Gas in oil... again

[Anonymous]

I've been finding any excuse the past two weeks to take Mongo out for a spin. After each ride (each being anywhere from 5 to 50 miles) I check the plugs, oil level and generally look the bike over to make sure he's happy. Last night when I got home I put him up on the center stand to check the oil and it was at the very top of the window. I figured I'd let it cool and check in the morning to see if it went down, it went up. Took the 710 cap off and stuck my nose in there, sure nuff, gas. I just went into the garage and checked the operation of the petcock and it's working. So now I'm confused again.
Things that have been done to date:
Rebuilt petcock w/ new parts
Rebuilt and cleaned carbs with new parts (orings, needles, seats, gaskets, jets, fuel screws, plugs)
Fuel screws set to 2 1/4 tuns out
Floats set to 22mm across the board
I tested the float seats when the carbs were off the bike by flipping them upside down and sucking/blowing on the fuel line and couldn't move any air through. If I flipped them right side up again, air moved freely.

It was running smooth and didn't seem to be sluggish, had plenty of get up and go when running, but was/is tricky to start if left alone for more than a day or so. I assume that's because the fuel is emptying from the bowls into the motor, but how?

Sorry if this is longish, I just want to get the info out up front.

Thanks in advance

-Sean

[shaftzuki]

You've got to have some junk that's keeping one of the floats from seating and shutting off the gas - doesn't take much, probably something that snuck by from one of your first rides, could have been floating around in one of the carb bowls until it became lodged in the seat ... Ain't it grand!! 8)

[earlfor]

Re: Gas in oil... again

As shaftzuki said, your float needles are leaking. If they were not leaking, then no gas could pass through them. However, if you petcock was not leaking, then no excess gas would be flowing into your float bowls in the first place and leaking float needles would not matter. Your problem is with the petcock. The float needles on my 750 have always seeped slightly and I have rebuilt them with new seals, needles , etc etc numerous times. Finally, I gave up with that approach about two years ago and replaced the petcock with a Pingel which is a mechanical off, res,on type...no vacuum line. The fuel in the crankcase problem has never re-occurred even though I know for a fact that the float needles do seep. That now doesnt matter because the fuel is positively OFF when turned off. I would replace the fuel petcock. (I have never had good luck with petcock rebuild kits).
For the money, I think it is a better deal to buy the Pingel, pay for it once, and NEVER have the problem again. You're DONE. :-) :-)
The first thing I do with any bike is install a Pingel petcock...even if the OEM petcock is perfect.

Earl


[quote="howmuch"]
I assume that's because the fuel is emptying from the bowls into the motor, but how?

[Anonymous]

You can't guarantee a perfect float needle seal, and expected seepage while running is insignificant. When not running, that seepage should not present a problem, because only the small amount of fuel in the lines available to gravity could intrude. Not enough to worry about (or visibly raise your oil level). A small amount of gas will boil out of the crankcase while you ride without damage to the engine.

Your problem is with a leaking petcock. I bought a new one. Money well spent.

Are you really pulling the plugs that often? Are you concerned about unnecessary wear to the plug threads? I change my plugs in the Spring. If you're running well, and no symptoms have already been apparent when checking the plugs, I'd leave them alone.

[Anonymous]

shaftzuki wrote:

You've got to have some junk that's keeping one of the floats from seating

You are correct sir....

earlfor wrote:

Your problem is with the petcock.

You are also correct sir...

I've been tinkering and here's what I've found...

I opened the screws in the bottom of the bowls and a little rust came out. I guess I have to kreme the tank sooner than I thought. I also hooked up a vacuum and fuel line external to the bike to tripple check the petcock. If I do the suck blow, suck blow, all is well. If I just suck on the vacuum line and stop, gas will keep continue to trickle until I blow on the line to seat the oring on the diaphragm and stop the fuel. The ONE part that did not come with the petcock rebuild kit was the spring for the diaphragm. It must not be strong enough anymore to seat the oring. I briefly thought of trying to find a spring that was strong enough to seat, but wasn't soooo string that the vacuum couldn't open it. Ya'll are right, pingle time.

Al wrote:

Are you really pulling the plugs that often?

I want to make sure the mixture is perfect, it's just a reassurance thing.
I didn't think I was getting very good gas milage according to what was being posted here, so I was reading the plugs frequently, and they were looking good. Now I know where the gas was sneaking off to.

Again, thanks for the help guys!

[SqDancerLynn1]

use a spring from an ink pen

[Anonymous]

Re: Gas in oil... again

[quote="earlfor"]
For the money, I think it is a better deal to buy the Pingel, pay for it once, and NEVER have the problem again. You're DONE. :-) :-)
The first thing I do with any bike is install a Pingel petcock...even if the OEM petcock is perfect.

Earl

I assume that's because the fuel is emptying from the bowls into the motor, but how?

I agree with Earl............Solved my Problems

[Anonymous]

It'll take you a while to remember to turn on that Pingel fuelcock, though;-)

Here's how it goes... You are having lunch and a bunch of Harley tpes roll in. You finish and decide to leave them thinking, so you fire up the GS, ease out onto the road and accellerate briskly through first and second, that's about the time the float bowls go dry and it falls on it's face, so third gear goes BBBbbbddddrrrrrr. If you are quick, you might get to it before you have to pull over and stop... Not that I have done anything like that.

[Don Lobacz]

Just to balance out this discussion a little in case new forum members get the impression that ALL old GS members recommend Pingels...

I've put 100K+ miles on my bikes and feel that the stock petcock is the best way to go. The rubber pieces in it last 15-20 years (which will be the same for Pingels), so make sure that the components are in good shape (springs, too). Make sure that you get the right kit and that it is installed correctly (there is a vent hole for the diaphram that must be routed correctly).

Dirt/rust can hold open the diaphram and allow a drip, but the problem must be dealt with at the source anyways. The Pingel will not drip, but the dirt will still go past into the carbs and plug up things there. Dirty tanks need to be sealed or they will get you somewhere else.

Also, stock petcocks can be easily converted to on/off functioning: put a stiffer spring behind the diaphram to ensure tighter sealing and plug off the vacuum connections. Use PRI to turn it on.

[Anonymous]

Just thought I'd give an update on this....

I decided NOT to get the pingle. The pingle would cost me as much as the shocks I wanted and I need those to lower the rear end.

Soo... I put a stiffer spring in the petcock and no more drips. I also added a second on/off valve in-line just for my own peace of mind. I'll post a pic when all is done. I kinda got side tracked with installing the new drag bars.

[argonsagas]

So far, so good, but if you have a little rust showing up, you have a problem that will do nothing but increase until it demands, and gets, your full attention.

I dislike using the chemicals to re-do the tank, and chose to have it done professionally on my 1100G.

The cost was about CA$90. and I got a multi-year written guarantee. A package of Kreem was $40., plus tax, so the professional job was twice the price, but I got no worries about handling dangerous chemicals or their deadly fumes, (and their ARE deadly) but just installed my newly coated tank.

If going that route, you would have to ask the gas tank/radiator repair folks about the effect on paint. Mine was already stripped and the needed body work done before it was cleaned and coated.