left cylinder misfire

D

dennis

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hi, my left cylinder started misfiring and i am really stumped as to what's causing it. i realised after that i had overfilled my oil (past the looking glass mark) and went for a two hour ride, took a break, and went back on the road and then it started misfiring. since the right cylinder fires the bike can still engage the gears. i was told that it was a blown head gasket because of the oil but my coolant level's hasn't changed. the left carb and intake had alot of oil and so i was thinking of opening the engine up but i'm not very confident in doing so. i have the manual but am not exactly mechanically inclined

what i've done so far:

-taken oil out using some piping to the correct oil level
-pulled the plugs and replaced them
-switched the boots to see if the misfire would switch sides
-drained carb floats
-pulled and cleaned the carbs and needles
-bought a new battery
-ran it with seafoam in the gas

the left carb was black with oil. also when i pulled over to see what was happening, the pod filter i had on literally blown off.

so i'm looking for guidance as to what i should do next.

what i'm planning on doing:
-switching coils to see if the problem switches side
-changing the alternator
 
Stop, back away from the motorcycle.

You have an internal engine problem - oil coming out the intake port, especially in sufficient amount to coat the inside of a carb, is Bad News. Blown head gasket seems plausible to me. Cease mucking about with it and get in touch with a mechanic ... a head gasket replacement may be affordable.
 
when i said i wasn't exactly mechanically inclined i meant that i'm not comfortable with working with the engine just yet. i bought a 250 with learning how to work on the bike myself in mind. so fari have worked with the carbs (changing the jets), removed the airbox and put pod filters, replaced my own chain and sprockets, put on a full pipe, and completely repainted the bike.

i'm in school at the moment and can't afford to pay for a shop to fix the bike. i live close to zdeno so parts are cheap. i was hoping some shop guys could point me in the right direction. i just don't want to spend a whole day changing the gaskets for nothing
 
Check compression on both cylinders. If the suspect cylinder's compression is found to be low, check and set the valve clearances (and it may be worth doing this regardless of compression results).

If the valve clearances are in a plausible range but compression is low, you've got bigger problems.
 
Brian P said:
Check compression on both cylinders. If the suspect cylinder's compression is found to be low, check and set the valve clearances (and it may be worth doing this regardless of compression results).

If the valve clearances are in a plausible range but compression is low, you've got bigger problems.
Click to expand...

Start with this. Then check spark on both cylinders. Then if everything comes back good, pull the carbs and clean them properly.
 
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