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tappet adjustment. 10mm of play what!!!!!

Posted: 12 Mar 2010, 10:34
by probey28
hi this is my first post to 80/90 so i hope you all can help.

i have a 2 litre aircolled t25. i'm completey restoring it. work on the body work has come too a halt for time being so turned my attention to the engine.
me and a mate tried doing the valve clearences last night. my mates a mechanic and so he set abot doing it the way he's done it on other stuff in the past. getting it on the rock then setting the gap. then we hit 2 major problems. firsly we found that the gap was getting on for about 10mm and that when we adjusted it down we never had enough adjustment. please could someone tell me are we doing it wrong or is there something really worn inside the engine

Re: tappet adjustment. 10mm of play what!!!!!

Posted: 12 Mar 2010, 11:06
by dj biz r
go to wiki type tappets in search bar hope this helps "this is what i should have done before playing with mine!"

Re: tappet adjustment. 10mm of play what!!!!!

Posted: 12 Mar 2010, 11:33
by Aidan
sounds like he's on the wrong cylinder when setting the valves
1-4-3-2
iirc do it backwards starting at 1 then you can do both on the same side then reseal the rocker cover before doing the other side

Re: tappet adjustment. 10mm of play what!!!!!

Posted: 12 Mar 2010, 12:14
by bigherb
Like Aiden says it looks like he is adjusting the wrong cylinder you adjust the opposite cylinder to the one thats on the rock. But if the engine hasn't run then the hydraulic tappets would have drained down causing the large clearance.

Re: tappet adjustment. 10mm of play what!!!!!

Posted: 12 Mar 2010, 19:56
by toomanytoys
As said...

sounds like hydraulic tappets leaking down..

no "adjustment" needed..

now what you need to do is to set them to just touching, then 1/2 (half) a turn in.. NO MORE (the 2 turns preload in haynes is far too much).. once its running it will be rattly for a while, need to take it up the road for a run, then it will be quiet.. run it on a mineral 15w40 or 20w50...