The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: jachenbach on 08.12. 2014 19:04
-
I spent at least an hour yesterday with a drill, impact screwdriver, and propane torch trying to remove the sludge trap screw plugs from a crankshaft. Finally gave it up and last night searched the forum for suggestions. Sorry I don't remember who posted the instruction to drill and use a #5 screw extractor, but I'd like to extend my heartfelt thanks. It worked beautifully.
I have been wondering why I was doing this, because the crank bearings, rod bearings, etc all seem to be in excellent condition. When I saw the crap in the sludge trap, I felt much better about having gone to the trouble. All clean now, and just ordered new plugs and a gasket set. Hopefully they arrive quickly and I'll get this engine back together.
-
Funny how I've never had to resort to that method. The air impact driver and a good bit never fails, even if I'm too lazy to drill the center pops first.
The sludge trap should be cleaned out EVERY time the crank is out.
Cheers
-
I hope you ordered socket hex ones.??
-
Yes I did order the socket type. They were actually cheaper than the slotted ones. Muskrat, I tried to use my air impact, but my bits weren't a tight enough fit. Couldn't keep it in the slot. At least I now know how. Soon as I get this engine done I'll be starting on another (I've got 2 engines and will be buying another chassis).
-
i had to resort to the drill and extractor method as a last resort when everything else just broke. i used a snapon on no6 parallel extractor 7/16". expensive but made job easy. to clean out the thread for the small journal plug i used5/8"whit tap special with 20tpi. [found on ebay] and watch out for obscuring timing side oil feed hole with a plug that may be too deep. plugs must be flush with web. it does help to have such info to hand on forums and avoid wasting the day with frustration.
-
Another way, that's almost free, is drilling a hole and driving an allen key into the hole to use as the extractor. This is a published approach and has been mentioned a few times on the forum.
Richard L.
-
hi richard, i tried that method but the tool rounded the hole under extreem force. i also tried welding a bolt in the drilled hole but that snapped also. i dont have gas bottles which would be another ideal method so it was a parallel extractor for me which worked.
-
Ed,
Just curious, is this the method you used, following the advice for drill size and allen key size? If so, I'll stop pushing it. It worked for me and I have not heard of it not working for others, until now.
The previously mentioned technique removes the damaged portion of the threads and should allow for the removal of the end plug, although sometimes it is necessary to obtain additional torque to get the end plug to unscrew out of the crankcase. To obtain this extra torque, drill into the center of the end plug with a 5/16" drill bit (again with a bit suitable for drilling metal). A 5/16" allen wrench should then be obtained and L-bend angle cut off such that the allen wrench can be driven right into the drilled hole in the center of end plug. A wrench can then be used to turn the allen wrench thereby allowing for much more leverage then a screw driver could have applied (Side Note: this trick was passed on to me by Brian Pollitt of the UK BSA Owners Club).
Richard L.
-
hi richard , i remember one plug came out fairly ok but the other was brutal to remove probably due to the peening. nothing wrong with your method except the plug is only mild steel and wont take a lot of torque before it moves in the hole, whereas a quality extractor is a splined shaft and will hammer in the hole and dig into the plug better. only my chosen method i m willing to share with fellow anoraks . any method that works for you is fine by me. i believe srm use welding torch heat and a punch which is probably the easiest method.
-
I always drill a 10mm hole in the plugs and weld a short bolt in. I think the heat off the welding helps
It has never failed yet wardley bob.
-
That's probably the best idea so far- if there's a welder handy.....I tried Richards method, but it failed so I butchered them by drilling so they collapsed in....
-
many many years ago, back in my uni days I blew up several triumph tigress 250's because I didnt know about sludge traps. It was a valuable if painful lesson. *pull hair out*
Always worth the extra effort and cleaning them out.
-
Hi RR, I to saw saw off a few tigresses 250's (about 5 plus numerous bsa versions and not forgetting 15 Raleigh mopeds ,should got a medal for that alone ) I dropped a floor and 10 cars on em *roll* sludge traps were the least of there problems after that *smile* :!cheers bob
-
Bob,
Do you mean there was a collapse of an upper garage floor on to the floor below? Hope no one was killed.
Richard L.
-
Yep Richard, got 'em right on the snout ,thankfully no one hurt just a line of bikes as listed and 'twas over the weekend. happened at my 2nd BSA dealership cundall motors in 1970, Idiot manager ( not me for once 😀😀) didn't see the point in wasting money on a survey of the 250yr old building *dunno* *dunno* so just went out and bought a shed load of rubbish which were deposited in the showroom over my clearance area full of said associated rubbish ,bit of a test really ,if I could sell them I could sell anything ,you get the idea. anyway I waltze in Monday and was almost sacked for nearly pissing myself laughing at the hole ,wasn't, the damage etc just relief of knowing I wouldn't have to Inflict that crap on someone, When I drive past the building now 44yrs later I still have an inane grin on my face ! BTW did you have a good holiday regards Bob.