Accidentally left on PRIME

[ssanderson1]

Hey guys....I don't mean to be non-PC, but I just can't think of a better word to describe myself than RETARDED!

I left the petcock on Prime on accident. It's been sitting there for a few days on the side stand.

I just tried to start it. I pushed the start button and heard a dull, low-toned pop, so I immediately released the start button. I noticed a small trail of liquid leading out of my garage. From what I can tell, the liquid is coming from the tube running down out of the airbox-carb piece.

The crankcase does not appear to be full of gas. My oil level looks, if anything, lower than a week or two ago.

I'm afraid I'll do damage if I try to start it again. Any ideas?? Thanks in advance. One day I'd love to pull my head out and stop making rookie mistakes. Ha

 

[cowboyup3371]

Check the oil again by smell and if necessary, drain it completely. You might want to also take the plugs out and turn the engine over by hand - I think anyway

 

[81ZUKI75]

Put bike on the center stand, jerk the spark plugs out, put the gearbox in 5th, rotate the rear wheel (in forward direction, see arrow on tire)....observe gasoline blowing out of spark plug holes.

Change oil....

The above describes MY experience

 

[bccap]

+1 on change the oil and filter. It's not worth taking a chance considering what the alternative could be.

 

[ssanderson1]

Should I change the oil, then pull the plugs and crank by hand? Or does it not matter in which order I do them?

 

[shinzon1]

I'd pull the plugs and rotate first. That way you don't contaminate your fresh oil with any gas sitting on the pistons. Although I doubt there would be enough to cause any problems, but that's what I would do.

 

[Agemax]

Put bike on the center stand, jerk the spark plugs out, put the gearbox in 5th, rotate the rear wheel (in forward direction, see arrow on tire)....observe gasoline blowing out of spark plug holes.

Change oil....

The above describes MY experience

or, just turn the engine over by hand, using the big nut on the end of the crank

 

[Crankthat]

Change the oil, run to clean.
Then change oil and filter again.
Run and ride bike.
You want to clean all gas out of case but just as important off the clutch fibers as they will break down if left soaking in fuel contaminated oil.

EDIT.. Of course that is only if you have gas in the crank case.

 

[ssanderson1]

Thanks for the help, guys. I'll try to get after it tomorrow.

I forgot to mention that I smelled just a tiny hint of gas in the crank case...even though I can't see any in there.

 

[chuck hahn]

Dont waste your time or energy with the manual turn over and all that crawling behind the bike it involves. Pull all the plugs and a rag over each hole..a few quick roll overs with the starter and your all set.


Drain the oil and a new filter...ride into the sunset and remember the petcock next time.

 

[Guest]

My 2 cents. If it was on the side stand and your floats are working like they should, then the gas more thdn likely followed the path of least resistance out the vent tubes and into the air box. How much gas was in the tank? Why did you have it on prime in the first place? I never put it on prime unless, 1) I'm running out, and prayer isn't working on it's own, 2) I did run out and I need to PRIME the empty carbs, 3) Drain the tank. You say there is a hint of a gas smell in the oil or are you smelling the gas that's still in your airbox. It is right there in the same vacinity. If you haven't changed your oil in a while, then do so, you needed to anyway, but if it's been recient, then drain it and inspect it. You'll know if there is gas or not. You could find ways to syphone some oil out and inspect your findings. I have access to 60cc syringes and clear tubing, but just the clear tubing and your thumb over the end will work. Remember your parents telling you not to play with your soda as a kid when you were doing the same thing with a straw. Actually a straw would work if you had a one long enough. If it looks good put it back in. I would pull the plugs and put a clean shop rag over the holes and use the starter. The cranking speed will repell the fuel, if there is any, up onto the rag. If you do discover gas in the oil, then pull the filter and replace. Well I guess that might have been 3 cents worth, good luck and quit putting it on prime.

 

[49er]

Yes, spin the engine over with the starter, once the plugs have been removed.

Just change the oil once. Any gas residues that remain in the crankcase will quickly evaporate once you take the bike on its next run. IMO, people get too anal about small amounts of fuel contamination.

 

[ssanderson1]

Alright, I pulled the plugs, covered the holes with rags and hit the start button. I was waiting for something spectacular to happen. One of the rags fell off....it had 5-10 drops worth of gas on it. All the other rags were dry as a bone. The rag with the 5-10 drops of gas was covering the far left cylinder(the same side that the bike leans when on the stand). I put the plugs back in and it started right up. White smoke came out of the left exhaust for 20-30 seconds then stopped.

The prime was on because I wasn't sure if the engine was getting gas(an earlier problem...) I just forgot to shut it off afterwards.

I really doubt there is any gas in the crank case. I'll probably change the oil anyway just to be safe.

Thanks for the help, guys! I sincerely appreciate your experience and willingness to help a guy out.

 

[chuck hahn]

The smoke was probably raw fuel that got past the exhaust side burning off.

 

[GSXR7ED]

Honest Mistake/Lesson Learned

Honest Mistake/Lesson Learned

Alright, I pulled the plugs, covered the holes with rags and hit the start button. I was waiting for something spectacular to happen. One of the rags fell off....it had 5-10 drops worth of gas on it. All the other rags were dry as a bone. The rag with the 5-10 drops of gas was covering the far left cylinder(the same side that the bike leans when on the stand). I put the plugs back in and it started right up. White smoke came out of the left exhaust for 20-30 seconds then stopped.

The prime was on because I wasn't sure if the engine was getting gas(an earlier problem...) I just forgot to shut it off afterwards.

I really doubt there is any gas in the crank case. I'll probably change the oil anyway just to be safe.

Thanks for the help, guys! I sincerely appreciate your experience and willingness to help a guy out.

Thanks for sharing your story. The key point is to learn from a mistake and try not to repeat it.

As of now I try to keep a full tank at all times. I don't wanna switch the indicator unless I have to.





Ed

 

[GER144]

Even if you had it on 'prime' the float needles are suppose to still do their job and not allow excess fuel out of the bowls, filling your crankcase/air box. If you do have fuel in the crankcase or airbox, the float needles/seats/seat o-rings are leaking and need to be repaired/replaced. Check the float heights too.
Todays crap fuel is hard on the o-rings around the float needle seats, and the needles themselves if they are rubber tipped.

 

[chuck hahn]

In a way yes AND no GER144. They ARE supposed to shut off the flow of fuel if floats heights are properly set. BUT.. They arent machined so precisely to not leak ever so slightly even when properly set up. In cases where the petcock is left on PRIme, the gravitated weight of the fuel pressing down will push fuel past them...regardless. Its just the way it works.

For this very reason, the petcock is designed to shut off the fuel as soon as the vacuum from the engine is gone..thus preventing the pressure of the fuel in the tank from even getting to the float needles in the first place.

 

[GER144]

I hear what you're saying Chuck and I understand how the vacuum petcock works. Vacuum petcocks are great. With the vacuum shut off, then there should be almost no way that the fuel can overflow the carbs. BUT, there are plenty of bikes out there that do not have vacuum petcocks.
Some stock bikes and ones with aftermarket taps (pingel) with just on/off and they have no trouble keeping the fuel from leaking out when left ON. (as long as everything is in good shape and adjusted correctly).
If the needles, o-rings, float heights are all correct, I still believe the fuel should not overflow if left on prime.
I ran my stock '83 katana for years with a pingel on/off petcock using stock carbs and VM33's and never once had a fuel leak/overflow issue leaving it in the 'on' position. But with todays fuel, that may be a different story!
With a vacuum tap, best to still not leave it on 'prime' just to be safe.

 

[shinzon1]

Most of our bikes have metal tipped valve needles. a small amount of fuel will leak past them if there is any pressure pushing past them like the weight of the fuel in the tank. Most ATVs and lawn mowers use a rubber tipped needle that is designed to hold the weight of the fuel because they don't have vacuum operated petcocks. Most of them are either on or off if that is even an option for off. The reason for this is that metal tipped needles and seats aren't machined to close enough tolerances to prevent all fuel from leaking past. The rubber tipped can form a complete seal as long as there is no damage to the needle or seat.

 

[Guest]

I've accidentally left both my bikes on "Prime" on the sidestand and yes they leaked.
I have since left one of my bikes on "Prime" again but this time no leak, the only difference I can think of was it was on the centerstand.
So, I'm thinking the level of fuel in float bowl being at an angle while bike on sidestand might not allow enough height to completely shut off the fuel resulting in a leak.