The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: JJH on January 05, 2017, 06:06:39 PM
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I am doing some long overdue maintenance. I have removed the cylinder and head. I carefully removed the piston/ rod from the cylinder being careful that it did not hit anything. I removed the circlip from the front of the wrist pin barrel ( a serious pain). I tried to then push the pin out the front. No joy. I heated the piston a bit and the pin move a bit. Then I got scared and stopped. I read a bit and it was recommended that I remove the pin from the rear. Why would this matter? I would assume the pin is symmetrical, but I also don't want to mess anything up. I will try to remove the rear circlip. Does anyone have any other tips, or failing that any new curse words to use? :)
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The pin is not tapered - remove it which ever direction works for you. The traditional method of heating the piston to release the pin is to pour boiling water over a piece of old towelling and then wrap the towelling around the piston.
A better and faster method is to buy a cheap heat gun and give the piston a good going over with it - be aware however that a heat gun can pump a lot of heat into a piston - wear gloves.
Above all else do not spend money on a ghastly tool called a "piston pin puller" - if you need one of these you got problems and using one when you don't need it carries with it the risk of damaging the bore in the piston.
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Like Tony said
get a decent heat gun your gonna need it for other repairs anyway
The cheap ones from Orielys don't last very long
They burn up
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Thanks for the help, first time doing this part, just being cautious.
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Agree with the others - remove the circlip from the front or back and go the direction you prefer (or is easier). I tend to prefer removing the front one (seems to be easier to see/access for me) and sliding the pin back toward the rear. A bit of heat, patient persistence, or some light oil and twisting back and forth of the pin (if you can get a grip on it with your fingers) generally seems to work on my airheads.
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Just curious as to why you are removing the piston wrist pin .
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Bob,
I want to clean the carbon off the top of the piston. I believe it will be much easier off the engine.
Thanks,
John
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Upon reinstallation of the pistons, there should be an arrow on the top of the piston, the arrow points forward .
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Upon reinstallation of the pistons, there should be an arrow on the top of the piston, the arrow points forward .
Ever since I got caught by a set of aftermarket pistons that were not so marked I put a daub of paint from a paint pen near the forward wrist pin hole.