The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: Guy Wilson on 14.09. 2015 18:38

Title: A small rattle in the engine department....
Post by: Guy Wilson on 14.09. 2015 18:38
During a ride at the weekend through the tea fields of Limuru, just north of Nairobi, a horrible rattle bought the bike to a halt faster than the front break ever could...
Initially I thought the dynamo chain had broken, when this was interacted, I though maybe its dropped a valve guide. Finally I thought, shouldn't those pistons be at the same height?
barrels off tomorrow. Its a mechanical 'pass the parcel' what will I find when I take the next bit off?
Title: Re: A small rattle in the engine department....
Post by: bsa-bill on 14.09. 2015 19:05
if the pistons are a pair that would be a yes then, so little end, big end maybe, timing side bush I think would have caused havoc before it got that much play, it will be interesting to see :(
Title: Re: A small rattle in the engine department....
Post by: Greybeard on 14.09. 2015 19:06
 *sad2*
Title: Re: A small rattle in the engine department....
Post by: RichardL on 14.09. 2015 19:57
A small rattle?

A few things I can guess at with little chance of being right.

1. We've seen a mod here on the forum where the crank was modified for, I think, 180 degree alternating up and down strokes between bores. I doubt that's what's going on here, so I'm not going looking for that topic to expand on the details.

2. Little end broke right next to the gudgeon pin letting one piston stay up while the rest of the rod rides up and down in the bore and, at the same time,  the other cylinder keeps running to propel the bike. (Talking to self: "But Richard, wouldn't the broken rod ultimately push the piston at least to the top of its stroke?") 

3. Piston fractured circumferentially at one of the ring grooves with same result (and same talking to self).

4. Broken crank?

If  a rod cap came off, the devastation to the crankcase would not be subtle.

I should just stop because, in fact, I really don't get this if the engine was still capable of running before disassembly.

Very anxious to see the truth.

Richard L.
Title: Re: A small rattle in the engine department....
Post by: bsa-bill on 14.09. 2015 20:42
Expanding on the possible but not probable scenarios, you have A65 con rod on one side, doesn't explain the rattle but might push you to get the barrels off and put the rest of us out of our misery  *smile*
Title: Re: A small rattle in the engine department....
Post by: muskrat on 14.09. 2015 20:52
Oh bugga.
I'd say rod snapped at big end or snapped crank. Time to look for a large journal crank & rods. *sad*
Cheers
Title: Re: A small rattle in the engine department....
Post by: chaterlea25 on 14.09. 2015 21:13
Hi,
 
BSF

Buggersh*tnf**k *problem* *problem* *angry* *angry* *work* *work*
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 15.09. 2015 05:19
ahmm...my tongue was very firmly in my cheek about the piston position. I've rebuilt / reassembled this engine's top end from the barrels up, so I do get the consequences of the piston positions. The engine is relatively low mileage, 20,000 or so but had only done about 50 miles since being put back together.

We'd been riding of about an hour an never exceeded 50mph. We were riding up a gentle hill, two up when this happened. There was no warning other than the engine appeared not to be pulling as strongly as it was, no unusual engine noise at least.  I put that down to the hill, two up and the 7000ft altitude. I had the clutch in almost immediately It made the noise, and coasted to a stop. It really did sound like the dynamo chain had broken and I was kicking myself because I didn't have an allen key to remove the timing case. if I had, I'd fully expected to be able to remove the chain and ride on.
When the chain was fine, I thought a valve guide or seat had dropped. It really didn't sound as serious as it obviously now is....
I'll pull the barrels off after work today and see what the real damage is.

More updates as I have them...

Thanks again for your thoughts. I'll have some serious and specific questions soon!

Guy
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 15.09. 2015 06:33
In responce to Richard's query. As soon a the 'rattle' started, I pulled the clutch in and coasted to a halt without the engine running. The picture of me looking at the engine is poetic license...The only noise at that point was 'how are we going to get home now?' from the photographer...
Guy
Title: Re: A small rattle in the engine department....
Post by: WozzA on 15.09. 2015 06:49
OUCH...  I bet you said a lot of IN & OUT words when you pulled the head off..   *doh*
good luck with what you find & the rebuild..  *wink2*
Title: Re: A small rattle in the engine department....
Post by: bsa-bill on 15.09. 2015 08:34
think I need my eyes tested again, I had not noticed the actual pistons in the pic, I was looking at the marks at the top of the bore left by the top ring which do look different but but no where near as bad as it is, hence my A65 remark.
If the marks I was looking at (top of the bore) are correct and not a camera angle thing then something has been out of place for a while and maybe not a sudden failure altogether,
Title: Re: A small rattle in the engine department....
Post by: duTch on 15.09. 2015 08:53

 Sorry, but I'm a bit short on envy for you... *cry*...when I busted a crank, it ran fine but had a rumble and a bad vibration (think earthquake)...

 I'm inclined to go with a dropped cap from the right hand rod bigend

 Not happy for you, hope it's not too bad good luck
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 15.09. 2015 09:09
let me pull the barrels off and maybe all will be revealed....Whatever the case, I've got to split the crankcase. I didn't split the crank when I rebuilt it as it seemed fine...'experience is what you generally  get just after you need it..' as my friend Charlie says..
Guy
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 15.09. 2015 09:11
yes it sounded more like a sudden failure. Certainly no earthquakes, it was more like an old alarm clock going off,
Guy
Title: Re: A small rattle in the engine department....
Post by: duTch on 15.09. 2015 09:24

 I guess a wayward rod cap would be a progressive thing though, something you'd notice
Title: Re: A small rattle in the engine department....
Post by: bsa-bill on 15.09. 2015 09:48
Quote
let me pull the barrels off and maybe all will be revealed

What!! and stop some of us making fools of ourselves  ;)
Title: Re: A small rattle in the engine department....
Post by: orabanda on 15.09. 2015 10:15
It is possible that 20,050 miles = blocked sludge trap
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 15.09. 2015 10:26
Lets not lose sight of how much fun this is...we'd all be driving electric scooters if we did.
Guy
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 15.09. 2015 12:35
It seems like the left hand con rod gave up. There's nothing left of the cup, just bits..The con rod  looks as thought may have had an existing crack or metal fatigue - part of the surface looks clean, like a recent break, the rest looks dull, like its been like that for a while as seen in the picture?
Any opinions on whether I can sleeve the barrels?
I have few evenings work here...
Guy
Title: Re: A small rattle in the engine department....
Post by: Greybeard on 15.09. 2015 12:37
Bloody hell; nasty!  *sad2*
Title: Re: A small rattle in the engine department....
Post by: RichardL on 15.09. 2015 13:46
Guy,

Sorry about your woes, but I'm sure you knew something was badly wrong when you took off the head. The award for correct diagnosis, of course, goes to Muskrat.

Richard L.
Title: Re: A small rattle in the engine department....
Post by: muskrat on 15.09. 2015 13:52
G'day Guy. *sick* yes she's been going for some time. I'd like a dollar for every " bottom end seemed/felt fine" only to let go shortly after.
Sleeve the barrels" Short answer is yes. The broken skirts would need to be blended (all rough and sharp edges removed) and crack tested.
 *sad*
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 15.09. 2015 14:32
Yes, thank you all. It could have been worse.. the cases seem intact although I won't know until I split them. I have a spare bottom end and barrels from a later bike. I was due to rid the bike in a rally on the 27th, so maybe, maybe, I might be able t o get it running on the second engine.
Good to get your opinion on sleeving the barrels. Again, it a benefit of this site that all you have to do is ask and answers come flooding back - all in a day! Much quicker than a Haynes manual - no disrespect
More photos to come.
Guy
Title: Re: A small rattle in the engine department....
Post by: groily on 15.09. 2015 18:16
Faced with that little lot Guy, you get my vote as 'Positive Thinker of 2015'.
For saying 'it could be worse' (let's hope it isn't when you have looked at the cases properly, but jeez, it's bad enough); and for wanting be out and about in 12 days' time using another set of bits. Why not??!!
The Very Best of Luck to you.
Title: Re: A small rattle in the engine department....
Post by: morris on 15.09. 2015 21:51
Faced with that little lot Guy, you get my vote as 'Positive Thinker of 2015'.

And mine...
Title: Re: A small rattle in the engine department....
Post by: trevinoz on 15.09. 2015 22:05
Maybe you should have opened it and cleaned the sludge trap.
Title: Re: A small rattle in the engine department....
Post by: RichardL on 16.09. 2015 00:28
Have you looked to see if there is still a bottom on your crankcase?
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 16.09. 2015 04:47
The sludge trap was clear and there appears o be no external damage to the crankcase.
I have to wait a few days before I can do much more..
Guy
Title: Re: A small rattle in the engine department....
Post by: RichardL on 16.09. 2015 05:50
Guy,

I'm probably chiming in too often, but now I'm really curious. Since you are talking about the external appearance of the crankcase, I take it you have not parted the cases. Without parting the cases you could not know if the sludge trap is clear. This leads me to think you may be mistaking the oil sump plate for the sludge trap. (Please pardon me now, if I am vastly underestimating your knowledge.) The sludge trap lives within the crankshaft and runs through both rod journals. It consists of a tube with holes in it that serve to separate, by centrifugal force, particulate that would otherwise stay in the oil and clog up the ways. If the sludge trap gets overloaded over some years, chunks might get released and block the holes leading to the journals, resulting in frozen rod bearings.

Richard L.
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 16.09. 2015 07:04
You're quite right, thank you,  I'd assumed the oil plate and wire filter was the sump trap. Just proves again how useful this site is how helpful it is to talk to people..My knowledge is expanding..
Guy
Title: Re: A small rattle in the engine department....
Post by: RichardL on 16.09. 2015 07:43
Guy,

I forgot to put in the obligatory "Don't ask me how I know" (DAMHIK). I know because when I did my first A10 engine rebuild I didn't know. It was about 100 miles (maybe) before my next rebuild, which was necessitated by a spun rod bearing.

Oh, one more thing. Everyone else here has a similar story.

Richard L.
Title: Re: A small rattle in the engine department....
Post by: duTch on 16.09. 2015 08:54

 ...and on top of all that, I hope you'll check over the spare that you're intending to use..? I bought Hex-Head sludge trap plugs from SRM..worth buying as many for as many motors you have..well, maybe at least two sets...
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 17.09. 2015 16:27
So I thought it best I strip my spare crank down to check the Sludge traps etc as I will use the spare until I know the state of the original,
Can anyone tell me how best to remove the gear on the end of the crank that sits below the oil pump worm. as in the picture below. There doesn't seem to be a way of getting a puller on it.
Title: Re: A small rattle in the engine department....
Post by: bsa-bill on 17.09. 2015 17:06
I always thought the two bits missing from the collar bit ( so vague I know) were intended for a puller, never used one tough.
I  use a hive tool, known to beekeepers, it's s very hndy bit of kit for all sorts of stuff.
insert the short L shaped end behind the pinion and apply pressure as if to force it off then give the end of the shaft a sharp tap, has worked every time for me. the tool is wide enough that you should not be able to damage the crankcase at all, goes without saying protect the threads on the end of the crank
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 17.09. 2015 17:29
Thanks Bill, that sort of makes sense and has logic. I'll sleep on it. I was nervous about banging the end of the crank unnecessarily, but if its necessary...
I'll post the pics of the broken bits tomorrow
Guy
Title: Re: A small rattle in the engine department....
Post by: chaterlea25 on 17.09. 2015 19:41
Hi Guy,
Theres a "special" puller for the gear
I machined up two legs that fit a universal 2 legged puller that works great
How tight they are varies from engine to engine  *eek*

HTH
John
Title: Re: A small rattle in the engine department....
Post by: duTch on 17.09. 2015 19:52

 Hi Guy, Similar to John, I used a couple of lengths of ~8mm threaded rod and welded a bit of 2.5-3mm plate on the bottom of each- not time to look now for a piccie though; use with uni puller
Title: Re: A small rattle in the engine department....
Post by: shabashow on 17.09. 2015 20:33
You're were really lucky there (if having broken a con rod could be called luck) that the rod didn't go through the side of the cases. Looks like all is repairable - all it takes is time and money! The barrels will be easily sorted by fitting liners. The previous owner of my bike threw a rod while trying to do 100 mph. The crank cases were destroyed and the barrels had the same big chip out of the bottom. I got them resleeved and they're just like new. I've got a 52 bike with 53 cases, crank and rods, 52 head and 2013 pistons :-)
You'll learn a lot, and hopefully have a worthwhile experience sorting your bike out. Plenty of advice available here, keep the forum updated with your progress, and I'm sure folk will chip in with good and useful advice to get the bike back on the road for another 20,000 miles or more.
John
Title: Re: A small rattle in the engine department....
Post by: muskrat on 17.09. 2015 21:53
G'day Guy.
re chaterlea25's post the puller is used in the slots cut in the pinion (see pic).
Sorry Bill but I think hitting the crank is the last resort before throwing it in the bin.
Cheers
Title: Re: A small rattle in the engine department....
Post by: metalflake11 on 17.09. 2015 22:53
One of the most depressing threads I've seen on here this. Horrible seeing bits of mangled and broken engine parts.
Good luck with the re-build Guy!
Title: Re: A small rattle in the engine department....
Post by: orabanda on 18.09. 2015 00:13
Hi Guy,
Hammers and engines don't mix; leave yours in the tool box!

Like others have explained, I found a compact 2 jaw puller at an automotive tool store. The legs were hardened (to be expected), and too thick to fit into the slots on the gear. I ground them down until they fitted, and have pulled apart dozens of A10 engines with this tool.

See the link attached; this is same the tool I modified - you have to grind the bottom of the jaws down (flat).

http://www.ebay.com.au/itm/Kincrome-Bearing-Puller-19-35mm-K8101-/390940122411?hash=item5b05d8dd2b

Alternatively, you might take your bottom end to an engine repair shop; they will probably have something similar and be able to pull it off for you.

Don't forget to clean the sludge trap on your spare crankshaft, or you will end up going through this again.

Richard



Title: Re: A small rattle in the engine department....
Post by: RichardL on 18.09. 2015 00:20
This got it done for me for about $8.00.

http://www.a7a10.net/forum/index.php?topic=8738.msg62472#msg62472

Richard L.
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 18.09. 2015 05:00
I'll go with the puller option. I'll figure out how to make something to fit..
Guy
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 18.09. 2015 07:01
Dutch,
The sump trap plugs from SRM you bought. Are they the same as the Triumph ones? I can't see BSA plugs listed.
I'm making a puller today!
Guy
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 18.09. 2015 07:53
found the correct SRM site now, so I'll write directly to them on the Sump trap plugs..
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 18.09. 2015 08:02
They seem very reasonably priced in comparison to not checking them...only slightly more than the cost of the fuel I used before it went so very wrong....
Title: Re: A small rattle in the engine department....
Post by: duTch on 18.09. 2015 08:10
 
Quote
.only slightly more than the cost of the fuel I used before it went so very wrong....
Yeah. .. Funny that. .. And they make it so much easier to check anytime you feel the urge *conf*....
 I dug out the pullers I made- no way I'd've found this morning in the half dark. ...Hopefully self explanatory, but I might edit them later on the big screen. ..

 edditt...?? They're a bit bodgy, but did the job;- maybe if you can check and confirm the thread form on these plugs, the ones that came out of mine were 7/8" 11TPI which match's 7/8" BSF, but a query here a while ago disputed that, so now I'm curious... and I hope you get the old ones out without too much drama!!
Title: Re: A small rattle in the engine department....
Post by: Greybeard on 18.09. 2015 09:16
found the correct SRM site now, so I'll write directly to them on the Sump trap plugs..
To avoid confusion, they are sludge trap plugs
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 18.09. 2015 10:46
My home made puller. A large washer with a nut and bolt welded on. Two slots either side (its adjustable!) and I ground off the heads on the two bolts so they would grab the gear. A jubilee clip held it all together and the gear came off very easy...hammer left in the tool box.
The sludge trap (thanks Greybeard for your attention to detail) looks horrible...
Title: Re: A small rattle in the engine department....
Post by: Greybeard on 18.09. 2015 11:19
That puller will now go in the box of home made special tools that we BSA'ers tend to have. In mine there is a tool to help reassemble plunger assemblies, a fork spring compressor, a BTDC piston stop etc.

I'm sure someone will chime in with a great method to get those sludge plugs out. I drilled out the centre punch holes and applied heat, (a plumbers gas torch is your friend), *an impact driver - [see image], (with the near crank web held in the vice*).

Wait till you see the shyte that comes out if the trap hasn't been cleaned for a while!

** Oh dear, now I'm in for a bollocking. The plug came out easily for me so no damage to the crankshaft; honest!
Title: Re: A small rattle in the engine department....
Post by: bsa-bill on 18.09. 2015 11:34
Quote
Sorry Bill but I think hitting the crank is the last resort before throwing it in the bin.

yep puller is the option of choice, if you have or can make one.

"hitting" covers many sins "tapping" is what I said and tapping is what you do once the puller has put pressure on the pinion - yes
Having  talked to on old blacksmith on our estate for many years and watched him shape, bend and weld metal with some of the many hammers that hung around his forge I conclude a hammer to be a tool of some finesse in the right hands.
(not saying my hands but you get my drift) - ha "drift" it's the way I tell em
Title: Re: A small rattle in the engine department....
Post by: RichardL on 18.09. 2015 13:44
The sludge trap (thanks Greybeard for your attention to detail) looks horrible...

I don't think the plug is out. Does anyone see a slot in the plug? i don't. If you're looking for ways to get the plugs out, here's the way I did it:


http://www.a7a10.net/forum/index.php?topic=1241.msg8886#msg8886

Oops, sorry. The link in that link is dead. Look,at the post above it.

There are other methods in that thread and elsewhere on the forum. For,example: drilling and using an easy-out instead of a hex key (per my chosen method); enhancing the slot and using a hammer-driven impact tool with a fat screwdriver bit; welding on a bolt that you can get a grip on, etc.  one thing about welding, you can always try that after trying the other methods, but drilling or enhancing the slot really gets difficult after welding.

Richard L.
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 18.09. 2015 14:08
The plug is not out...I read up on the drilling method option. It looks easier and less traumatic. I've ordered some new sludge trap plugs from SRM, so as long as the old ones come out without damaging the crank, I'll be happy.
Guy
Title: Re: A small rattle in the engine department....
Post by: RichardL on 19.09. 2015 01:17
With the hex-key method, as long as you drill in the center of the plug you shouldn't be risking damage to the threads in the crank. Of course, you've already read about lightly drilling out the punch marks used to keep the old plugs in place. Behind the plugs you're going to find a tube inside the crank. This is held in place with the radial flywheel sludge-trap fixing bolt. Not too big a problem if the tube is damaged, as they are readily available. The tube and fixing bolt are not shown on all exploded views of the crank assembly.

Richard L.
Title: Re: A small rattle in the engine department....
Post by: Greybeard on 19.09. 2015 08:45
Behind the plugs you're going to find a tube inside the crank.

No tube in mine.
Title: Re: A small rattle in the engine department....
Post by: duTch on 19.09. 2015 09:21

Quote
    Behind the plugs you're going to find a tube inside the crank.


No tube in mine.

 Could be wrong, but I think the small journal cranks didn't have them, just the LJ's...?
Title: Re: A small rattle in the engine department....
Post by: muskrat on 19.09. 2015 09:53
It would be a small journal unless a PO changed it. The SJ has 6 bolts around inside the of the flywheel.
Cheers
Title: Re: A small rattle in the engine department....
Post by: RichardL on 19.09. 2015 13:09
Yes, looking down into the crankcase that's on the bike you can see that it is small journal, and that jive's with it being a '55 (learned by going back to Guy's earliest posts). However, the spare cases are from a later bike, as Guy said. The shape of the crank around the plug, and the size of the plug itself, says to me (am I "hearing things"?) that the spare is large journal.

About that plug, it almost looks like someone tried to weld it over or remove it by the welded-bolt method and failed. Guy, are you sure there is a threaded plug there?

Richard L.
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 19.09. 2015 16:40
I fortunately ordered both sizes from SRM so I should be covered on plugs. I'm sure they're a minor point the greater scheme of things.
I'v almost got the original engine out of the frame and will probably spilt the crank tomorrow.

I have a related question regarding spanner sizes. I have a fair number of imperial spanners that are marked in fractions etc. I bought them at Halfords in the UK.  With the exception of the 1/2 inch and the 7/16 i think, nothing much else seems to fit. I have a couple of old spanners of my fathers that are marked BS (British Standard?)  Can anyone give me an education on spanners. What should I be using? 
Title: Re: A small rattle in the engine department....
Post by: a101960 on 19.09. 2015 17:11
Quote
I bought them at Halfords in the UK.

Guy, I think that you might well have bought a set of AF spanners. As far as I know Halfords only sell AF and metric tools.

John
Title: Re: A small rattle in the engine department....
Post by: bsa-bill on 19.09. 2015 17:40
You need Whitworth stuff which although easily available here in the UK might cost a bit to post to Kenya,
here is a conversion chart that might save you a bit if you have some spanners already

http://classicmechanic.blogspot.co.uk/2011/06/mm-af-bsw-bsf-spanner-conversion-chart.html (http://classicmechanic.blogspot.co.uk/2011/06/mm-af-bsw-bsf-spanner-conversion-chart.html)
Title: Re: A small rattle in the engine department....
Post by: muskrat on 19.09. 2015 20:38
http://www.sat.dundee.ac.uk/psc/spanner_jaw.html#Jaw_Size_Table
Common sizes on BSA 1/4, 5/16, 3/8, 7/16 BS
Cheers
Bill got in 1st.
Title: Re: A small rattle in the engine department....
Post by: trevinoz on 20.09. 2015 01:18
The small journal crank has a different sized plug to that fitted to the large journal crank. The one with the tube, that is.
The Road Rocket L.J. crank uses the same plugs as the S.J.
Title: Re: A small rattle in the engine department....
Post by: WozzA on 20.09. 2015 08:20
& the small journal doesn't have a tube inside..

well mine didn't..  *wink2*
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 21.09. 2015 04:51
All in all I think I've been very lucky. The Crank cases appear undamaged. The crank looks repairable
I've not got the sludge traps out yet,
Title: Re: A small rattle in the engine department....
Post by: RichardL on 21.09. 2015 05:00
I mean, don't take my word for it because there is much more expert advice than mine here on the forum, but I think that left rod may need to be replaced. ;)

Richard L.
Title: Re: A small rattle in the engine department....
Post by: Greybeard on 21.09. 2015 09:03
We need an empathy Unlike button like Facebook is getting.  *sad2*
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 21.09. 2015 09:50
I don't know for certain yet, but I will once I've removed the conrods from my spare crank, I'll know whether they are interchangeable or not. I've seen small and large journal references on a couple of websites, so I  may be looking around for a spare conrod or two...all part of the learning curve and stuff I can pass on to others in the future no doubt...
Guy
Title: Re: A small rattle in the engine department....
Post by: muskrat on 21.09. 2015 10:21
Yes mate your very lucky not to have more damage.
looks like a small journal from here. Give us a pic of your spare.
Whichever one you use get it crack tested and measured for true. Any 2nd hand rods are going to have a few ??? marks. They have a limited life span. New ones would be best if budget will stretch.
Cheers
Title: Re: A small rattle in the engine department....
Post by: RichardL on 21.09. 2015 12:03
Guy,

I apologize for picking a bad time for attempted humor and making it just a little too dry. The left rod is the one that is fractured and crumbled. That said, the right rod, which is still on the crank, may have taken a thrashing from the flying debris inside the crankcase.

It looks to me that the crankshaft web might be distorted on the left side. That makes me concerned for how straight and true it is through the centerline of the journals.  When you say the crank is repairable, are you referring to the distortion I think I'm seeing in that crank web? I could be imagining it. Anybody else see something odd about that left web?

Richard L.
Title: Re: A small rattle in the engine department....
Post by: Topdad on 21.09. 2015 12:10
Now you mention it  is at an odd angle .If it is twisted it's taken an almighty clout to do that .
Title: Re: A small rattle in the engine department....
Post by: Guy Wilson on 21.09. 2015 12:16
I'll stick it on the lathe at the crankshaft grinders and see if/how straight it is.
Title: Re: A small rattle in the engine department....
Post by: bsa-bill on 21.09. 2015 12:35
Quote
Anybody else see something odd about that left web?

from the photo I'd say nigh on impossible to say either way, I think Guy your going the right way getting it tested/measured
Title: Re: A small rattle in the engine department....
Post by: muskrat on 21.09. 2015 13:45
OK now be honest. How many looked at the right side web then moved their head to the left to get a straight look at the left web?
I did  *bash*
Cheers
Title: Re: A small rattle in the engine department....
Post by: bsa-bill on 21.09. 2015 14:11
up here on the topside of the globe we have to lean the other wat *smile*
Title: Re: A small rattle in the engine department....
Post by: RichardL on 21.09. 2015 15:10
I don't have the bell-shaped crank on either of my bikes, but that sppears to be the type on Guy's. Bike. In the attached photo, the plunger crank that is shown does seem to have a chamfer which I may have confused for distortion. I'm sure there are better pictures out there and people (you know who you are) that actually know the facts here.

Richard L.
Title: Re: A small rattle in the engine department....
Post by: duTch on 21.09. 2015 19:36
 
Quote
OK now be honest. How many looked at the right side web then moved their head to the left to get a straight look at the left web?

 I'm digitally advanced- clicked and dragged the photo over... *eek*