[C-Leigh Racing]

Only way, a 250R engine wont run lean & rev some once the fuel level is below or past the bottom end of the pilot jet, is if it somehow has been extended deeper down into the carb bowl or either the slide has been adjusted so it will close completely & have no idle at all.

If the silde has even the slitest crack, at the bottom of the venturi, that engine will suck air through that crack & run untill theres no more fuel being drawn in to supply it to run.

All my riders, be they on a 250R or a Yamaha blaster, their engines dont idle, at all & each have to learn how to ride the bike like that. When they chop the throttle, the slide closes.
Neil

 

[C-Leigh Racing]

What you could do, buy a can of VP C12 so you can keep it sealed & get one of those small qt size run tanks with the petcock on the bottom, mix up a qt of race, drain each carbs bowl & then hook the little bottle up & fill the bowl back up with race mix. Will last a whole lot longer than pump & you wont have to think if its hurting the engine any.

Lot of people dont realize, you out riding somewhere, stop, kill the engine & then cut the petcock off & then later start up & take off, only to remember about when the engine starts to stumble you forgot to turn it back on, it hurts that engine to some amount when that happens. The engine is hot & lower the fuel got it that bowl leaner the engine ran.
If the owner is the type of person likes to run the jetting right on the edge for top power, its even worse on their engine because it has so much heat in the engine to start with.

Its ok what your doing, anythings better than nothing. Most dont bother & just deal with it later.
I predict your engines probably lasting awhile, just by staying on top of things.
Neil

 

[C-Leigh Racing]

I do the same as you do, just pull the chock up when the revs increse.

Matt,, you need to be carfull pulling that chock up.
Say you pull the chock up & your doing the run the gas out the bowl deal, it revs up & jumps in gear & takes off. You done pulled the chock up & nothing to keep the bike from taking off. Hope nobodys standing in front of it.
:mellow: :huh: Neil

 

[C-Leigh Racing]

Oh lord! the things these boys have to put up with running PUMP gas.
Good quality race gas will last at least 6 to 8 months sitting without gumming up the jets.

When I did mower repair business few years back, 95% of the engine repairs I did was fuel related problems.
Carb rebuilds, stuck valves when they tryed to get by without repairing the carb, changing oil because it had gas in it where the float hung over the winter & gas ended up in the crankcase.

Briggs & Stratton almost went broke from replacing 12HP rider mower engines, & it realy wasnt their fault 90% of the time. You might could even say 8 of the 10% left it wasnt either, because of the out soursed gasket maker putting release agent on the gaskets so they would come out of the stamping dies faster.

Customer put the mower up in the fall, full of gas, you know, just like they heard the old folk say to do,,,,,,, pulled it out next spring,,, FILLED it up with gas & went to cutting,,,, did ya'll see that,, filled the gas tank.
About 2 passes across the yard cutting & the rod blows out the side of the block. Lucky none of the rod pieces hit the owners foot or feet or else that would have been a law suit for Briggs to deal with. See here again not Briggs fault, cause its no way they could hold each owners hand & show them every little detail every time they got ready to turn the starter key.

Now, where was I at,,,,, oh draining the carb bowl.
It is a good idea, to a point, but understanding what or why you are doing it is just as important.
Reason is the gas going stale & turning gummy. Gas sitting & being allowed to vent, is allowing the chemicals mixxed in the gas to vaporize out. Those chemicals added in are what keeps the gas from turning gummy in the first place & once they are gone, you know now whats next.

I would say, running with the petcock off, untill the engine revs up from the pilot not being able to pick up fuel & going lean, is to some amount just correcting some of the problem, or preventing one.
Even once it does rev up from being lean, you still have fuel in the lower part of the bowl around the main jet, BUT, the main jet has a bigger hole & less prone to gum up like the pilot will.
So, on a scale of 0 to 10, I would say doing its worth an 8.75 & it realy depends on the quality of the last batch of gas you put in the tank & the amount of time you leave the bike sitting.
Still, a good thing to do though, better than just leaving it as is & then hoping it will start & run next time you pull it out.
Neil