650 - Dumping fuel into oil

[Guest]

Guys,

I'm just about ready to scrap the thing, so help in restoring my sanity would be appreciated!

1981 GS-650 Katana.

Had problems a while back where it started dumping fuel out of the carb overflow pipes when running. Extremely poor performance.

New float valves fitted, heights etc checked and reset where needed. Performance greatly improved to the point where it would try and spit you off the back from 3000rpm upwards.

Fast forward a month or two, and the cases have been split for a complete geartrain replacement. All back together.

Oil level checked and re checked, as it was a dry fill (started up and checked/topped up as required repeatedly). Took it out for the first time today since. Oil level spot on (checked before I started it up).

Went 12 miles to bike shop, to get junior a new pair of boots. Not impressed with the performance, very lethargic, didn't really take off when given gas.

Parked up at bike shop, put on to centre stand (so I could check the oil again before I left, after it had had chance to run back down).

When I came out, oil level was totally above the sight glass (ie over full). Oil smelled heavily of fuel.

Any ideas as to the cause?

The fuel valve is fine (sat for a month with a 3/4 full tank off the bike and didn't leak a drop).

Over the 12 mile run, there was no pinking or other abnormalities heard.

The idle speed always has been a bit hit and miss, but today it was anywhere from cutting out when coming to a stop, to sitting at 2000rpm.

If that amount of fuel had been dumped down over 12 miles when it was running, surely I would have known about it (pinking/meltdown/clouds of smoke)?

So far i've only been able to pull no 1 & 4 spark plugs, due to my plug socket going walkies (resident teenager? - Probably!). 1 looks a little sooty, and 4 is fine (beigy/brown colour). Pity I can't check 2 & 3 as of yet.

I'm suspecting a carb problem of some description. The last time I had them apart (3 months ago), everything checked out fine. I'm just wondering due to the high mileage (69,000), the carb bodies have worn down, resulting in sticky pistons courtesy of excess clearance.

Any other suggestions? Or does anybody have a set of carbs (BS32) at a reasonable price, so that I can swap them out?

Thanks,

J

[hjfisk]

Check your petcock, pull the vacuum line and check for fuel there. There should not be any. It is common for the diaphram to go bad and leak there

[G0FHM]

Hmm.... You could be correct!

I forgot to factor in the petcock!

Obviously without the engine running, the spring will keep the O ring in the seat, stopping fuel flow. If there is a hole in the diaphragm.... Well yes, I remember now!

Will check it tomorrow.

D'oh!

James

[Steve]

I'm just about ready to scrap the thing, so help in restoring my sanity would be appreciated!

If it will help restore your sanity, I will be happy to scrap it for you.

By the way, where are you?

.

[G0FHM]

If it will help restore your sanity, I will be happy to scrap it for you.

By the way, where are you?

.

Steve,

If it was only that simple.... It belongs to she who must be obeyed, and such a decision is ultimately not mine! I'm just the poor soul that has to put up with the damned thing

Located in Norfolk, UK

J

[Steve]

By the way, where are you?

Located in Norfolk, UK

Might we convince you to add that to your profile?

Maybe even a short sig to mention the bike?

Makes things easier down the road, you won't have to remember to mention them when you ask questions.

.