Smells of gas

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#1 Unread post by **t_bonee** » Tue May 17, 2005 2:23 pm

Hi all,

When I having been practicing on my bike, I have noticed that it smells of gas when it is running. Not really raw gas but kinda of exhausty gas, it still as a bit a raw gas smell but it has an exhaust smell too.

Also there is some slight smoking coming out of the exhaust pipes. Not too bad but if you look you can notice it. If I goose the throttle up it comes out more and the goes back to being light.

Are these two problems related and what could be the cause?

Thanks.

Tom

Gadjet · #2 Unread post by **Gadjet** » Tue May 17, 2005 3:46 pm

sounds like your bike is running rich. Probably wouldn't hurt to have your carburetors adjusted and synchronized.

#3 Unread post by **t_bonee** » Wed May 18, 2005 7:37 am

Thanks for the tip. Is this something a inexperienced mechanic could do? Or am I better off just having the shop guys do it. I'm kinda on a budget but don't wanna get in over my head either.

Also, I forgot to mention that the smoke that is coming out is either white or light blue. It was twilight when I noticed it and like I said it wasn't heavy or anything so I couldn't tell the exact color. Does that change the diagnosis?

Tom

poppygene · #4 Unread post by **poppygene** » Wed May 18, 2005 7:56 am

Hey, Tom!

First, I'd better ask you to tell us everything you know about your bike, the more the better. Otherwise, we might lead you in the wrong direction!

Next, I'll ask you to remove the oil-fill plug and take a good sniff down the hole. Smell gas in the crankcase?

#5 Unread post by **t_bonee** » Wed May 18, 2005 1:48 pm

poppygene wrote:Hey, Tom!

First, I'd better ask you to tell us everything you know about your bike, the more the better. Otherwise, we might lead you in the wrong direction!

OK. Letsee. 1982 Suzuki GS650L. Bought as-is from the Harley dealership down the street. It was a trade in. They said they didn't get any service records but supposedly it had regular maintenance. A little over 10,000 miles. It seemed to run good when I looked at it. It is in good shape (it seems to me) for a 23 year old bike. My uncle drove it home and told me it ran well and he didn't feel or notice anything that seemed wrong. Though that was only about 2 mile drive. I've only been riding in my driveway to get the feel for the friction zone and starting on hills so it never gets out of first or going very fast. Seems to do fine on that little bit of riding. Nothing that is obvious fromwhat I can tell. Just the smell of gas and the smoke I mentioned in the other post.

The stuff I've noticed is not engine related. Horn kinda stutters, some screws on the front brake fluid reserver is stripped, low beam on the headlight doesn't work. Stuff like that.

poppygene wrote:Next, I'll ask you to remove the oil-fill plug and take a good sniff down the hole. Smell gas in the crankcase?

Yes I do smell gas when I do that.

Tom

poppygene · #6 Unread post by **poppygene** » Wed May 18, 2005 2:28 pm

Man, I hate it! So far it sounds like you may have a similar problem as in this thread, but maybe not quite as bad:

http://totalmotorcycle.com/BBS/viewtopic.php?t=2336

It isn't necessarily the carbs, though. Your petcock may be leaking, causing way too much fuel to enter the cylinders and get into the oil. The easiest thing to fix is the petcock, so you may want to investigate that first.

#7 Unread post by **t_bonee** » Wed May 18, 2005 3:14 pm

poppygene wrote:Man, I hate it! So far it sounds like you may have a similar problem as in this thread, but maybe not quite as bad:

http://totalmotorcycle.com/BBS/viewtopic.php?t=2336

It isn't necessarily the carbs, though. Your petcock may be leaking, causing way too much fuel to enter the cylinders and get into the oil. The easiest thing to fix is the petcock, so you may want to investigate that first.

Could this be the result of the petcock being put into the PRI position when it is not needed?

When I got the bike home, I noticed I could not turn the petcock at all I think(it was in the ON position though. Can't remember for sure that was 2 weeks ago

), after a couple days I figured out that the key in the ignition had to be turned all the way over to the "P" to move the petcock valve. I moved the petcock to all three positions to make sure it moved. It was in prime for only a few seconds, long enough for me to get it in, a slight pause then move it back to reserve then the on position. The petcock is kinda tough to turn so it may have had more time in the prime position.

Is it possible it was primed to much? Should I change the oil first then check it again after that to see if the smell is still there?

Tom

poppygene · #8 Unread post by **poppygene** » Wed May 18, 2005 3:45 pm

Setting the petcock to Prime for a few seconds shouldn't cause a problem, unless a carburetor float valve(s) is not seating or out of adjustment. If everything is working properly, setting the petcock to Prime should only allow the carbs to fill to their normal level.
I don't think the petcock should be hard to turn. The fact that it is makes me think that it is defective. You can get a rebuild kit for the petcock, but you'll want to get a sevice manual for your bike before tackling it.
I think you should first check your oil level before draining it. If the crankcase is too full, it may have a lot of gas in it. Then yeah, go ahead and change the oil if you want, but you need to find out how the gas is getting in there and get that fixed or else the fresh oil will be ruined before you know it.

Gadjet · #9 Unread post by **Gadjet** » Wed May 18, 2005 6:18 pm

My bike is an 83 GS650L, and I've had both problems that you are experiencing; a leaking petcock and a carburetor with a stuck float.

The petcock was easy to fix - take it off the tank (make sure you elevate the tank and tip it forward in order to clear any fuel that is left in the tank away from the petcock - you don't want it dump fuel all over the place)

take the petcock apart and check the condition of the vacuum diaphragm as well as the vacuum inlet - there is a little tiny hole in the inlet that allows air back into the chamber to release the diaphragm and close the valve. carefully clean this out, then reassemble - my petcock is also quite stiff, but I can't see the key position having anything to do with that, as they are not connected in any way ( at least they aren't on my bike, and the manual that I have doesn't say anything (covers all GS650 models, 81-83))

If your petcock is leaking, it will fill the carburetors and then the excess fuel will flow into the cylinders and the air chamber on the back of the carbs, where it will leak out the drain tube - is there a puddle of fuel under your bike?

If there isn't, then chances are your carbs are fine and just need to be synchronized, and possibly taken apart and given a good cleaning.

with only 10k miles on the bike, it is unlikely that you have problems with valve seals or rings going bad allowing fuel to get past and into the oil.

#10 Unread post by **t_bonee** » Thu May 19, 2005 12:35 am

I will try to check the petcock this weekend. The smell of gas in the crankcase isn't terribly strong or anything, but it is there.

So yours turns with the key in every position? On mine, the ignition has 4 positions Lock, off, on, P (which you have to push the key down to get to it, like the lock position). The only way my petcock will budge is if I move the key to that P position. Then it moves. It is stiff but not so bad that I have to strain to turn it or anything. Just stiffer than other bikes that I tried that on.

Also there is no puddle of any kind under the bike. Just clean pavement.

Thanks to all of you for providing insight and your help with this problem.