What Are The Symptoms Of Crankshaft Seal Leak

[nicbrrghs]

Im trying to get my 2003 270 running. At the minute when it runs sounds fine then dies and wont start again. apparently the 'expert' has tried different stator,coil,cdi etc. Hopefully nothing big but im questioning crank seals or piston rings as ive not had time to strip it as yet. It has cost me a lot of monies so far and still have a broken bike.

If its seals how expensive/difficult is it to fix them?

Any ideas welcome.

Thanks in advance

[zerorev3rev4]

wouldnt of thought the seals would let it run for only a short time n then stop it from running they would tend to cause a lean mixture due to sucking in air which would cause it to rev high at tick over also if looking at seal behind flywheel it could be wet with fuel ,,, if g,box side seal gone it could cause oil to blow out breather or it could suck gear oil in and smoke badly ,, changing seals wouldnt be too difficult ,, i would how ever use a car type strobe light and see if it fails to light when the bike cuts out this will determin if loosing spark ,, if thats ok you need a compression tester ,check when cold then run untill stops and check again ,( it does sound like gummed or jammed rings you could remove front pipe to have a look ) if thats ok try putting fuel down the plug hole after its cut out and see if it can fire on that ,,, has it been stood prior to this problem ,, did anything happen on last ride ,has anyone borrowed it could there be water in the fuel does coolant look ok and have no bubbles or steam when it does run ( wondering if head gasket has gone ) this should keep you biusey for a little longer then report back have fun

[nicbrrghs]

Thanks for help will be looking on Monday/Tuesday.Some good things to try there thanks.

[tltel]

I assume the expert has checked the fuel system, cleaned carb, checked flow from tank, cleaned carb banjo filter (dellorto) checked tank breather and fitted a new plug.

Always change the plug with this sort of problem, they are cheap and easy, just to eliminate it.

Crank seals are also quite cheap and easy enough to do but you will need a flywheel puller. (although it doesn't sound like a seal problem)

good luck and let us know what you find.

TLTEL

[nh014]

I have had a similar symptom on my 2003 270 numerous times. All easily fixed be removing and throughly cleaning the carb, especially the pilot jet. Do that first before undertaking more costly and time consuming alternatives.

[wobblenorbed]

Has it been stood a while before you tried working on it? It`s all ways worth changing the fuel when you clean the carb if it has been in there a while or of unknown origin. Dirt in the fuel will all ways end up in the carb ! Good luck.

[dan williams]

Expert doesn't sound very expert. If the crank seal on the primary side fails you will get transmission oil coming into the bottom of the crank and get a smokey exhaust and a fairly distinct smell of burning tranny fluid. A leaky seal on the other side will lean out the air fuel mixture causing pinging and loss of power. Neither will give the symptoms you describe unless oil is fouling the plug. The problem with Beta stators is pretty well known to be an issue with the trigger coils. Often they will put out a marginal pulse that is enough to trigger the CDI until the coil warms and the output drops below where it can fire the CDI.

As described a blocked pilot circuit can look like this if using the choke. Bike will essentially run on the choke circuit and then die when it warms up and the choke is flipped off. If you can start the bike at 1/4 throttle or with the choke on that's a good indication of a blocked pilot jet. Fuel starvation is another possibility and that is where the tank vent in the fuel cap comes in. Water in the fuel also comes to mind. Modern pump gas has ethanol in it which absorbs water (displacing oil in the process, bad for two strokes) however water that gets into the tank and isn't absorbed will sit in the lowest part of the tank and can get sucked into the fuel system gagging the carb.

As my esteemed colleagues have noted above start with (inexpensive) basics. Drain fuel tank and put in fresh premix. Disassemble carb and clean out with compressed air. Check condition of reed petals to be sure none are broken. Make sure fuel is freely flowing in fuel line and that fuel cap vent is open. Fresh plug and check plug cap, possibly replace in case plug cap resistor has broken down. Throw a compression tester on and kick a few times with the throttle open just to make sure you have adequate compression. Low compression will make a bike harder to start. I'm not sure but I think the last time I did the compression experiment I was seeing about 140PSI on the '08.

If that doesn't explain the failure I'm still thinking stator.