hoggyf Posted May 3, 2016 Share Posted May 3, 2016 Decided to check the valves on my 4RT today and haven't done it on this before but have on previous bikes.All 4 valves were tight, couldn't get the feeler gauges under any of them so set it to TDC (checked Pistons was at top too, valves on the rock although its hard to tell on them) set the crank on the T mark and slackened the adjusters, wound the tappet out and reset to correct clearance then put all back together. When I tried to start it, it now has massive compression, it will turn over and can't hear anything untoward but doesn't want to start and the compression just "feels" wrong, so gave up for the day and to have a think. The only thing I could come up with last night at 10pm was that I hadn't reconnected the electric plug on the tank but can't see that making any difference. I must be missing something very obvious but any one any suggestions? Quote Link to comment Share on other sites More sharing options...
on it Posted May 3, 2016 Share Posted May 3, 2016 hello hoggy you have time timed it up on wrong stroke remove sparkplug and use long screw driver and check piston is tdc with timing mark(T) on fly wheel Quote Link to comment Share on other sites More sharing options...
sportsawyer Posted May 3, 2016 Share Posted May 3, 2016 Make sure you are at TDC on the compression stroke. And only turn the engine in the normal running direction, don't back up to the TDC mark -- if you overshoot a little, go another 2 revolutions. Quote Link to comment Share on other sites More sharing options...
hoggyf Posted May 3, 2016 Author Share Posted May 3, 2016 Thought I was on the comp stroke as piston was at top (checked through spark plug hole) and valves "rocking" ??? Why should I not back it up to get back the the T mark?? Quote Link to comment Share on other sites More sharing options...
sirdabalot Posted May 3, 2016 Share Posted May 3, 2016 Valves need to be closed, not rocking, to check valve clearances. Quote Link to comment Share on other sites More sharing options...
petert Posted May 3, 2016 Share Posted May 3, 2016 If the valves were rocking they could have been on the top of the lobes= 1 complete revolution out. If so no wonder it won't start as the valves are probably not opening Quote Link to comment Share on other sites More sharing options...
johnnyboxer Posted May 3, 2016 Share Posted May 3, 2016 I did say that 1 Quote Link to comment Share on other sites More sharing options...
spen Posted May 3, 2016 Share Posted May 3, 2016 I did say that "Doctor, everybody ignores me..." "Next." Quote Link to comment Share on other sites More sharing options...
ourian Posted May 3, 2016 Share Posted May 3, 2016 (edited) Why should I not back it up to get back the the T mark?? Because of Backlash You need to be at TDC on the compression stoke i.e. after the inlet valve has closed - not after the exhaust has closed suck squeeze This TDC bang blow not this TDC Edited May 3, 2016 by ourian Quote Link to comment Share on other sites More sharing options...
hoggyf Posted May 3, 2016 Author Share Posted May 3, 2016 Where's the egg on the face emoji?? On the wrong stroke oops, it is 28 yrs since I was taught lol all sorted now though and back running, at least I realised something wasn't right before starting!! Quote Link to comment Share on other sites More sharing options...
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