Hi all, I'm new here, just bought a 92 FZR, really like it, but it has one problem. When the bike is cold, it takes about 5 minutes to start, luckily it has a good battery as it just keeps cranking! With full choke on slowly it starts firing picking up more and more until finally its running, usually a hint of throttle helps. Any ideas on why its like this? Tomorrow I am going to check the valve clearances, and resistances in the ignition system. It runs perfectly once warmed up by the way. It sounds like it has bugger all compression when cranking like this, do they always sounds like this? Thanks, Mark - New Zealand
prolli start by looking at the plugs. have a squiz and bang a new set in if you have any doubts about the ones in there, chances are that this will get it started, but not fix your problem. get your carbies/fuel pump etc checked out if your not up to it yourself. the 250/4 are such small motors that they turn over easily, if you are comparing to bigger bikes or cars it may sound like its low on comp, but it aint likely. if in doubt, check out compression, but if it aint blowing too much smoke, then i doubt it.
Thanks for that, will check plugs when im doing the valve clearances. Can do the carbs myself, but just wanted to rule out everything else first. When I test the compression, how much should I be looking for?
Over 110 is safe compression. 125+ is more ideal. If you have a lean setup it'll be more of a bitch to start when cold (like mine) but 5 minutes is a tad excessive..
if its running over rich, it will flood and you can end up cranking a long time, esp if the plugs get wet, wet plugs do not spark if your going to the level of doing valve clearances then do your carbs properly and after that, id be surprised if you have any problems... be very carful on thesaes little carbies as float level is CRITICAL!!! 1mm difference will make the difference between a well running fzr and one that is a bitch to start and seems to be slower than your mates cbr...... lol as soon as you see your plugs you will know whats going on. my bet is they will be overly sooty. you will prolly find that if it is over rich, that once you get it running, if you pull the choke it will stall, even when cold.
Hey on that note, what does it mean when your bike stalls if you put the choke on too quickly? Mine splutters if i do it slowly but doesnt stall.
It means you shouldn't put the choke on so quickly <!-- s --><img src="{SMILIES_PATH}/icon_smile.gif" alt="" title="Smile" /><!-- s --> A choke either decreases the amount of air going to the engine (hence "chokes" it), or slightly increases the amount of fuel going to the engine (technically an "enricher" not a choke). In either case, turning it on too quickly results in flooding the engine.
Hi, Took the plugs out after a few minutes cranking and they were still quite dry, after taking the tank and airbox off and sticking rags in the inlets, the bike started alot quicker, obviously pointing towards a lean mixture. Have taken the carbs off so will pull apart tomorrow. Can anyone lead me to carb specs, float level, etc? Hopefully I find something in the carbs or I'm running out of ideas!! Mark
Finally got it sorted, tested the compressions, got about 80 on the outer 2 cylinders, and nothing on the inner 2. Turns out all the inlet clearances are very tight. Nobody can supply shims around here so I'm getting them machined at the moment. Hopefully it should solve my problem, might even make it go better! Thanks your help guys, Mark
