Author Topic: 54 650 head gasket blowing  (Read 2186 times)

Offline chaz

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54 650 head gasket blowing
« on: 13.02. 2013 21:35 »
started the old girl up ready for the MOT now its near after having it 5 years... was running ok before christmas now it seems to have blown the head gasket, runs but pops and bangs a lot and weeps on left side.  been told its got flat top pistons. as Ive not been inside the motor since Ive had it any hints and what about the flat tops good, bad ??
allways willing to learn
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Offline chaterlea25

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Re: 54 650 head gasket blowing
« Reply #1 on: 13.02. 2013 22:02 »
HI Chaz,
I dont believe gaskets fail while sitting in the shed??????
Firstly, check compression on both cylinders
Then sparks, try new plugs??
If the fuel has been sitting for a while drain it off and refill with fresh stuff, it doesnt take long to go off  *sad2*
You can also check the head nuts for tightness, its common enough to have a weep from the pushrod tunnel area
Wheres it weeping from??
Flat top pistons are fine for everyday riding

HTH
John
1961 Super Rocket
1963 RGS (ongoing)

Offline chaz

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Re: 54 650 head gasket blowing
« Reply #2 on: 13.02. 2013 22:18 »
Hi John, congrats on your 1000th post *eek*
modern fuel is poor, Ive just picked up a 750 guzzi not been on the road for 5 years yet with new battery and a few mins of cranking it started. the A10 has been run but for some reason seems to be dribbling out of the head joint, even seems to be a small bubble around one of the headbolts not weeping but air bubbles. bolts seem tight , just wondered if its unburnt fuel pressurised as tried kicking it over with a flat battery?
allways willing to learn
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Offline chaterlea25

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Re: 54 650 head gasket blowing
« Reply #3 on: 13.02. 2013 22:44 »
Hi Chaz,
Does your A10 run on mag or some other type ignition? electronic or distributor??
A mag doesnt need a battery???

I dont like the bubbles coming up the boltholes  *eek*
quite often the bolts are reluctant to thread any farther into the cylinder due to rust/crap in the threads
something to watch out for when you replace the gasket

Quote
Hi John, congrats on your 1000th post eek

Jeez that makes me feel really old  *ex* *ex*

Cheers
John
1961 Super Rocket
1963 RGS (ongoing)

Offline muskrat

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Re: 54 650 head gasket blowing
« Reply #4 on: 14.02. 2013 07:00 »
I must be ancient  *conf*.
I've seen bubbles coming from bolts that have had too much oil on them when tightened. When hot the air gap at the bottom of the bolt expands and bubbles the oil out. Flat tops shouldn't blow head gaskets. Check all that OLD John has mentioned.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline chaterlea25

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Re: 54 650 head gasket blowing
« Reply #5 on: 14.02. 2013 09:55 »
Hi Musky,
They say that "A man is as old as the woman he is feeling"  ;) ;)

John
1961 Super Rocket
1963 RGS (ongoing)

Offline muskrat

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Re: 54 650 head gasket blowing
« Reply #6 on: 14.02. 2013 10:26 »
Bugga, she's 3 more than me. *spider*
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Online bsa-bill

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Re: 54 650 head gasket blowing
« Reply #7 on: 14.02. 2013 10:44 »
Congrats John on you becoming a Kilomaileter, does your age theory mean I'm best not to take on a job as a  toyboy (might have just missed qualifying age by a decade or two mind). edit - like Musky *smiley4*
Now young Chaz flat head pistons are just fine, early bikes had dished ones (6.5 to 1 IIRC).
Compression test as John suggests would be good
would try to find out precisely where the oil is coming from, could be it's leaking oil into the a cylinder and fouling a plug, would examine both.
Yes now flat battery - not a problem if it is magneto for sparks if it's electronic then the test is easy just charge up the battery to full and then try it, most electronic systems seem to default to full advance when the battery gets low, so even if it fired up it would run wrong at low speed until the charging system got the battery up to at least 11 volts
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline a10gf

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Re: 54 650 head gasket blowing
« Reply #8 on: 14.02. 2013 14:32 »
Quote
Jeez that makes me feel really old
Should instead make you feel really helpful and valuable ! Congrats with the 1000 mark.

chaz, some things to look at, cylinder\head surfaces perfectly flat ? Torque wrench for the bolts (and re-tightened after a while) ? Tightening sequence > http://www.a7a10.net/BSA/techpics/sequence.jpg ?


A10 GF '53 My A10 website
"Success only gets you a ticket to a much more difficult task"

Offline a10gf

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Re: 54 650 head gasket blowing
« Reply #9 on: 28.03. 2013 23:09 »
How did it go ?

A10 GF '53 My A10 website
"Success only gets you a ticket to a much more difficult task"

Offline chaz

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Re: 54 650 head gasket blowing
« Reply #10 on: 29.03. 2013 08:32 »
just see a small mark where its been blowing , putting it all back and now one of the rocker bolts has a stripped thread!! got 4 new coming from Drags today.
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Offline bassgreg

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Re: 54 650 head gasket blowing
« Reply #11 on: 20.05. 2014 18:13 »
I have a similar question.

I paid some serious cash for a complete rebuild on my engine, it has sat in a crate for the ten years since, but been turned by hand regularly and it was full of graphogen paste.

I have been gradually checking things over and running the engine up slowly checking things over as I go. I now have what I consider to be a significant amount of oil running down the left barrel fins, shining a light into the gap between barrel and head shows a few bubbles popping from the head gasket while the engine is idling. I cant see any leak around the rocker gasket seals which leads me to believe it is the head gasket. And if it is the head gasket, where is the oil likely to be coming from? The only oil way is the pushrod channel, correct?

As yet the engine has not been under any load, I run it up to warm, checking the fuelling, idling timing etc.
It is entirely possible the head bolts simply need a re-torque, or it might be something more serious.

As a start, does anybody have the correct torque settings ( or know where I can find them ) for a 1957 plunger engine. They don't seem to be in the Haynes manual.
If that fails then I am into a complete strip down, in which case I am going to be in a right grump.  *smile*

Online trevinoz

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Re: 54 650 head gasket blowing
« Reply #12 on: 20.05. 2014 22:12 »
Could be coming from the front oil drain, there's one from each pocket in the head.
Torque to 30 foot pounds.

Trev.

Offline ericjervis

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Re: 54 650 head gasket blowing
« Reply #13 on: 02.06. 2014 18:38 »
Hi Bassgreg, I had the same problem, and thought the gasket had blown. Silly me, it was solid copper, and in fair condition. How I wished I'd taken the advice of my mate next door and just torqued it down a bit. But he rides japanese bikes so I put myself through a few weeks of aggravation instead.

Offline bikerboy

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Re: 54 650 head gasket blowing
« Reply #14 on: 05.06. 2014 00:15 »
started the old girl up ready for the MOT now its near after having it 5 years

Maybe I am reading this wrong but if its 1954 it does not need an MOT ?????????