Apparently my clearances need to be adjusted. How tricky is it to replace the shims? I’m limited in experience, is it advisable for me to give it a try? Any suggestions on where I can source new one from in Cape Town? My bike won’t even start at the moment – are incorrect clearances a possible cause?
In correct clearances when cold will definitely cause trouble starting the bike. If you have any mechanical knowledge or experience and have the service manual (or the FZR400 one) then go for it! Just be sure you keep track of everything you remove or move, and understand what your meant to be doing BEFORE you do it. If after reading through the procedure in the service manual your at all unclear on what your doing, it might be worth paying a mechanic to do it for you properly first time. If you do stuff up, it can be rather expensive to fix - after all you'll be doing things like removing and reinstalling cams.
For valve clearance checking and adjustment try looking at this posthttp://fzr250.com/viewtopic.php?t=1597 I would try a few other things first though, like checking the plugs and seeing if you have fuel at, etc. Have you seen the engine running? Did it just refuse to start one morning? Was it sitting for 12 months? Will it start if you put oil down the bores via the spark plug holes? The full story will make it easier for other members to offer advice.
Ok here the full sob story... Bike was starting fine for the first month I had it. Stated making a noise like the exhaust was gone. It was sugested that I check my EXUP cables to see if they had snaped. Checked the cables, and they seemed fine. Put everything back and started the bike to let my friend here the noise. Next day it would not start, turned over fine but not firing We pushed it - still no fireing Replace the sparks, checked they were sparking. It fired a bit, still would not start. Bought some Quick start, sprayed it into the air intake. Fired more often, still would not start, could feel pressure coming bak onto the air filter when it fired. Took it to someone who knows more about bikes than me, they said it was clearances. This was about 3 weeks ago Any sugestions... I'm starting to feel that this may not have been a clever purchase...
Sounds a bit like valve problems. It is not hard to check the clearances just follow the procedure that I linked to in the other post. If the clearances are ok, do a compression test as the valves may need a grind or at least re-lapping by hand. The test should be between 100-160psi ( should just run - near new condition). If oil down the bore fixes compression look for a good second hand engine as I believe rings are made from un-obtainium and nobody has them.
ROFLOL! <!-- s:lol: --><img src="{SMILIES_PATH}/icon_lol.gif" alt=":lol:" title="Laughing" /><!-- s:lol: --> That's the best line i've heard recently describing motorcycle parts. Gold, pure gold! In regards to how to do a compression test... you'll need to go purchase a compression tester thats appropriate for your spark plug size. Most of them are one-size-fits-all, so just head down to an Auto store and ask for a compression gauge. It's just a matter of removing the spark plugs and sticking the compression gauge in there and cranking the engine over. The maximum pressure that's registered on the gauge will be your compression in that cylinder. As Dave said, ~160psi is in near mint condition (i think 175psi is what most engines these days achieve once they've been properly run in... assuming you run it in properly!), where as anything approaching 100psi is a little on the low side.
