Oil smells of fuel
 

Arfter some time sitting around I decided to get my Honda dominator ready for a trip to tunisia next year,It was running a ruff before I parked it up but due to work I havn't manage to get it sorted anyway just been out to the work shop and before I start it I thought I would check the oil when I did it seems a little high and really smells of petrol dose anyone have an idear on what the caurse would be?

Cheers
Gary

There aren't many ways fuel can get in the oil, the most likely being the fuel is leaking trough the carb into the piston chamber and through the rings into the sump. Could be a "open" float valve( faulty float) and a leaky fuel tap even if it were shut off during the time it was standing. Check the overflow pipe is not blocked which will come from the carb float chamber. If blocked the only way out for excess fuel is through the engine.

This may well answer for the rough running previously.

A good clean and replace a few bits should sort it. There will be a "carb kit" available for this.

Riding with fuel in oil is likely to end in a very bad day! :taz:

Thanks for the info will get on with it tommrow and see if i can solve the problem

If its been sitting and the oil is old its hard to tell. Old, past its best oil can smell weird. Best bet would be to give it an oil and filter change and monitor it from there. When piston rings are very worn you can get exhaust gases pushing down into the crank case causing contamination and also you can get contamination from the valve oil stem seals.

Don't be worried just yet though. Give it a service.

OK ted I've just taken thecarb off so i'm going to strip that then cheak and replace parts as needed then i'll give the bike a full service and go from there.

So emtyed the oil out engine cold the oil was thin like water and really smels of petrol.So took the carb off all the rubber parts are in good order but the slow jet was blocked the rest seems in order will check the float hight today.
I removed the rocker cover to have a look at the chain it seems in good order but maz need a small adjustment as there is a bit of slack but have to find out how much there should be.One strange thing is that the tappets in the cover are all freemoving bar one (B) it is very stiff I dismantaled it and put it back together but no change and i can not see any obvious reason any thoughts.

Cheers
Gary

Hot oil runs like water.... Don't worry :)

It will love the service..

The oil was cold ted i think not so good
:(

Cracked Piston?
 

Yeah.. not good..

the rise in oil level + the smell says cracked piston to me.

May be able to verify it with a camera down the spark plug hole.

Uhhh. No, not so good. Still, too early to condemn it..

Never a good sign that the oil and fuel comes in contact unless you have a twe stroke engine.

So I have drained all the oil out Not good 4.25 ltrs:(.So not sure how much it should have I think no more than 2.5ltrs?.So I geuss its time to stripe down the cylinder head and beyond lol.or invest in a bore scope and as suggested what ever the problem the old girls going to run like a dream after ive finish with it and there will be a bit of peace off mind to go with it.

Took the head off today done a leak down test and all the valves are leaking inlet and exhaust top of the piston looks good filled the the top of the cylinder with petrol will leave it over night to see if the rings areshot but i-m thinking the fuel tap left on and open valves are my problem what do you think?

If you're certain that your valves are leaking then it certainly is a problem.

With Dominator's, the engines are prone to the valve seats getting loose while hot. If you suspect this, you need to have new valve seats pressed in.

These engines are pretty solid and stand up to a lot of abuse but many have seen many miles, with little TLC and are starting to show their age.

However, they're simple engines. Easy to work on for a home mechanic.

I am going to be rebuilding my XR650L engine soon (same engine) and here is what I'm probably going to do. Mine burns/leaks a litre of oil every 100 miles. I bought it that way.

1.Head removed and completely stripped, cleaned and de-coked.

2.Valves replaced with new Stem seals and they will be lightly lapped in. (Kibblewhite Black diamond valves - Cheaper and better than OEM)

3.Bore honed and new rings fitted. Maybe an oversized piston to 101mm if the bore is Yet to be measured. Lots of companies make good value pistons and rings.

4.New camshaft and cam chain.


This will probably cost about £300-£400 in parts, gaskets and consumables.

It sounds expensive but is still cheaper than getting a GS serviced at a local dealer and your engine will be like new.

Parts are cheap in the USA. Even with shipping and tax, they're often half the price than getting them from a UK dealer.

1995 XR650L A Honda Motorcycle Parts

Thanks for info ted the valves are not leaking really bad and i think that if i lap them they will be good the cam and chain look really good asdose the top of the piston,but just been out and checked the feul in the piston and its gone so cylinder off in the morning and for sure new rings and as you said i might go for an over sized piston depends on the state of the bore.