gas smell in crank case and rain put a damper on my power

Hi - I have a 1980 650 XJ Maxim

A couple of questions from a neophyte to motorcycles and engines--I tried to search the forum but I don't have the lingo to know what to search for:

(1) where should I start to look/fix if there is the smell of gas in my oil crankcase? Is that what might be affecting my ability to start the motorcycle at times? The starter seems tempermental.

(2) We got caught in a wicked downpour today. After waiting out the worst part of the torrential rain and the lightning and thunder (under a big tall tree on a hill!!) on a gravel side road, we headed out through the rain--but my bike was now quite reluctant. It seemed gutless and got worse as we travelled in the rain. Once I was back on pavement, I could get very little acceleration power and had difficulty making it above 40 to 50 kilometers/hour (24 to 35 MPH). I stopped at a friend's to empty my boots out and was ready to leave the bike and pick it up at a later date--but after sitting for over a half hour (and the rain had pretty much stopped), it seemed to work again. It idled slowly at first and then seemed to rev itself back into life until the old character and power returned. Any suggestions/ideas?

Many thanks,
Carol from Kingston, Ontario.

 

As for your 2nd question, it sounds like you need to tune up the carbs. Rain can effect a bike, but once warmed up, normally not so. The indecision of the bike to settle on a an idle speed is a good sign of that.

As for the first question, I would go ahead and change your oil and see if the smell returns. If so, then I wouldn't know where to start. Do you have smoke coming from your exhaust pipes?

 

Re: gas smell in crank case and rain put a damper on my powe

Rain will tell you about all your electrical problems. Likely while it was wet you had one or more plugs not firing. Once you got it out of the rain the engine heat dried out and the problem rectified itself.

Go over your wiring harness. Make sure all the connectors are clean and tight. Pull the fuel tank off and run it in the dark. Look for any blue glow around the coils, ignition wires and spark plugs.

Gasoline in the oil is common in these bikes and indicates that you have 2 problems:

1) The fuel valve is vacuum operated. It should only deliver fuel in the ON or RES positions when there is engine vacuum. Unless you have been leaving it on PRI (which is only used to fill carburetors that have been emptied for some reason) you have a problem with the fuel valve. In my case this was caused by the seal behind the lever, some people need a complete rebuild.

2) The float valves are letting the carbs overfill. This could be mis-adjusted floats but most likely you have a leaking needle valve.

DO NOT OPERATE THE MOTORCYCLE WITH FUEL IN THE OIL. Solve your problem(s) and change the oil and filter before running the engine.

 

MiCarl, I think you nailed it with the carbs.

When Carol first got the bike I did the older brother thing and had a look at it. The valve on the fuel tank works as per advertised. I had the tank off and the fuel only comes out when the valve is set to prime. I don't have a manual here for the carbs (maybe someone could post a breakdown schematic) but can the float valve be changed from the bottom or do the carbs have to come out?
- Is there a way to check which carb it is?
- Would a tapping with a hammer help unstick the float valve?

As to the electrical question what's next if there is a glow around the coils etc? I'm guessing here but does one coil feed cylinder 1-4 and the other 2-3? Would she need a new coil or can you spray them with something to waterproof them?

Thanks for the help....tom

 

You might get the floats off on the bike but it would be far easyer and less likely to damage anything (the float posts can break) having the carbs off the bike.
You can "fix" the coils with a product that is a sprey on electrical tape.

 

Re: gas smell in crank case and rain put a damper on my powe

Thanks for the tips everyone. When I get some tools and a knowledgeable helper (aka - brother Tom from Ottawa), I can give each a try.

I have read elsewhere in this forum about changing the Petcock--I do smell a lot of fuel fumes around the switch -- is this the same as changing a valve seal?

I find all of this quite overwhelming but I am not anxious to pay someone over $70/hour to have a look at it either.

 

Re: gas smell in crank case and rain put a damper on my powe

It really is well within your ability to do a lot of your own work on your bike. Sometimes you just have to decide you want to go ahead and do it and not pay someone else (who may not even do as good a job as you could do!).

Its possible the petcock could be leaking intermittantly based on vibration or temperature. Fuel may even be leaking from the vacuum port. The rebuild kits are about $25.. maybe worth doing for some peace of mind.

 

Re: gas smell in crank case and rain put a damper on my powe

Well, the summer has come and gone, and I finally have the opportunity to update what I did to my bike. I changed the oil. I added Sea Foam to the gas tank, and opened the carb drains to drain the gas out and then sprayed a little bit of Sea Foam in the outlets. The bike was up and running wonderfully after my brother changed a spark plug, and I refilled the gas tank with yet a little more Sea Foam. And it continues to run well, without any other work. Woo hoo!!

Unfortunately, it was in the shop for over a week in order to have a bolt drilled out and the hole tapped when one of the exhaust collars broke off--the broken bolt was really welded in there and was very difficult to get out. It took the mechanic several hours and drill bits before it was done...and then the exhaust pipe had to be welded where he had cracked it in the process....And most recently, I managed to stupidly break off the brake lever when it got caught on the mirror of a friend's car as I tried to get up my steep driveway and past the car...right on the Saturday of a long weekend, with fabulous weather and all of the shops closed and no replacement part available...Ahhhhh!!!

Perhaps this weekend, the part will be in and I will be on the road again...

Thanks again to everyone for the input.

 

Re: gas smell in crank case and rain put a damper on my powe

I had a similar issue of poor rain behavior with my good 'ol cx500. When it was acting up, I pulled it into a darkened garage, and immediately found where one of the plug wires had cracked and was arcing to ground. I never would have seen it in the day! Best part of it was, I fixed it with electrical tape!

 

I had the same bad perormance in rain and two things fixed it.
1. I checked my wiring and found that the PO had rewired the coils in and left the primary connector wires exposed. So I rewired them and sealed them with heatshrink.
2. I pulled the coils and coated them in liquid electrical tape. Last rain I was in resulted in no problems.

 

If it's water that might be causing your problems then take off the spark plug caps and spray them with WD40, Yes the WD does stand for Water Displacement. Spray everything, the coils and where the ignition lines come from there to the spark plug caps. If that is the case then you have a water problem and not a spark problem.
Check that out, its only 4 bucks for a can of WD40 and your time to get the water out.

 

Broken studs are a quick removal with a TIG welder. The heat breaks those puppies free every time.

 

Re: gas smell in crank case and rain put a damper on my powe

What's a TIG welder? I guess I should have posted the question...it would have saved me 3 hours of labour cost and parts, etc. The bill came to just over $312 CDN. I guess he couldn't get the exhaust pipe off easily either and left it on and found it hard to get to the spot.

 

Tungsten Inert Gas welding. Great toy for welding. Most good shops have them.