Whaite smoke at idle
I recently obtained a 1984 RR 250. It has 19000 on the clock. I replaced all the obvious components like battery plugs oil filter, sealed tank, cleaned petcock. It starts up and runs smooth too.
My problem is this.....
... Whenever I start the bike, especially after its been sitting (say overnight) and even more so when Its colder outside, it releases a grayish white smoke from the exhaust. It almost smells like an old gokart or something. It will eventually dissipate, but i can still see faint smoke. Usually if its colder outside, it hardly goes away at all.
So what gives??
Is it bad valve stems? Bad head gasket? Cracked valve head? Bad piston rings?
Im really stumped, and I would like to fix this myself (even though ive never been inside of an engine but I learn fast! especially being a biochem major!). Id rather not get the shaft from the two local stealerships/mechanics.
IF anyone has any knowledge of or experience with this problem I would appreciate any input you may have. Thanks very much,It's normal for white smoke to appear out the exhaust in colder temps - there is a small amount of water present in gas that gets burned in the combustion process and is released as vapur, or white smoke, out the tailpipe. Other causes of white smoke are blown head gaskets on liquid cooled bikes - but as yours is air cooled, this obviously isn't the problem. Next time this happens, check the outlet of the muffler closely... if you see lots of water droplets coming out with the smoke then I'd suspect cheap too low octane of a fuel. Try a higher octane to see of the problem goes away.
White smoke can also be caused by unburnt fuel. If a spark plug is erratic in operation (ie: misfiring) it can fail to ignite the fuel/air mixture in the cylinder under compression forces and shoot it out the exhaust valve as white smoke. One other cause is the engine running too lean. As your bike is fairly old, I'd check the condition of the carb rubber intake boots. If they are cracked, this can allow air to get sucked in and lean out the mixture, causing white smoke. Another clue to a lean engine is that it will run very hot and the headers/exhaust pipes will turn a deep blue.,,,
Nov 10, 2008 |
2006 Beta RR 250