its fine to do that ,done it for years..

 

Should be ok!
If its gonna be sittin for a period of time which is pretty rare for me
I like to turn the gas off and then drain the bowl.
I feel more comfortable doing it that way.

 

So even though it seemed to rev up REALLY high..... quite a few thousand rpms I would think.....

Sorry, just want to be clear.... LOL

 

We used to do that after every trip with our 3 wheelers, both 2 stroke and 4 strokes. When it started to rev up from going lean, I would just be careful and try not to rev it too much. I quit doing that now and haven't had any problems with the carb after sitting for 3 or 4 months.

 

Thanks for the suggestions.... I will try it and see how high it actually revs. I was in the garage, and I know the echo is deceiving...

 

I actually have not taken the R on a trip to know whether I will have gas storage problems. My problems always come from the kid's DRRs, but the main jets are tiny in those, so any blockage is a big deal....

 

I do this after almost every ride. When the idle starts getting up there I just give a quick tug on the choke to drop the revs.

 

Ooooh.... good idea!

 

im pretty sure if its revvin when it runs outa gas your jets are off. you need to try a richer pilot that should fix the problem.

 

im pretty sure if its revvin when it runs outa gas your jets are off.....

you are huh ? ..can you explain why you think thats true ?..have you ever done as described above ..deatons 1st post ?

 

The pilot sucks fuel outta the bowl too, just like the main, so as the fuel level gets lower in the bowl the pilot starts sucking up some air too. It's like trying to finish a drink through a straw, and the last few drinks include air because the straw is bigger in diameter than the available soda....

As the pilot begins getting a mixture of fuel and air (due to the fuel level in the bowl getting low), the engine begins to rev, because of the increased air in the mixture....

That is my take on why this happens...

 

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

 

The pilot sucks fuel outta the bowl too, just like the main, so as the fuel level gets lower in the bowl the pilot starts sucking up some air too. It's like trying to finish a drink through a straw, and the last few drinks include air because the straw is bigger in diameter than the available soda....

As the pilot begins getting a mixture of fuel and air (due to the fuel level in the bowl getting low), the engine begins to rev, because of the increased air in the mixture....

That is my take on why this happens...

mine also .. good description ..just want to hear what he says ...concerning the pilot jet

 

you are huh ? ..can you explain why you think thats true ?..have you ever done as described above ..deatons 1st post ?

yep i fixed my cr 125 by doing that. as it ran out of gas it would rev up high. put a bigger pilot in it and no more rev up. if you pull the choke and it fixes it its usually true. My 250r does not have this problem anymore either.

 

hhhmm, not sure that explain the theory or reasoning ..
does it start good now ? ..1st kick or ? ...how many ?

ever ned to change main afterwrds or foul any plugs ?


use the choke to start ?

so your machine(s) NEVER rev up as the bowl looses gas ?
still not convinced that fixes any real problem that may have or not have been ...convince me


just asking questions cause I want to understand more on your point / suggestion etc

 

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

 

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

 

LOL.... Such drama Neil!

Yes, I am a pump gasser. We ride dunes, and will go through about 30 gallons in a weekend, just my family. I have two kids quads (DRRs), no way they are going to run on race gas, and this 250R.

With 30 gallons per weekend, that is ~$270 in race gas I would require, on top of 130 gallons in diesel round trip for the dune trip, plus any camping fees. You can see how things would add up so fast it would knock us right out of the sport.

The reason I don't have new KTMs all around is because of money. If I were making 6 figures per year I would not hesitate, but I am not.

To make our trips nice, stress free, and easy I keep everything on pump gas. I have to deal with a little bit of hassle (main jets clogging), but that's no big deal.

This post was to simply figure out a way to keep me from haviing to compressed air the mains out before each trip, making things EVEN easier.

At the cost of pump gas versus race gas, I could have a big bore kit within three trips, just with the savings. I understand you know what you are getting with race gas, and I respect that. That is why I keep my compression nice and low so I KNOW I can run pump, not on the hairy edge of needed high octane at all. So I sacrifice a little power, big deal. There is always someone faster, I am counting on being able to outride them.

 

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

 

hhhmm, not sure that explain the theory or reasoning ..
does it start good now ? ..1st kick or ? ...how many ?

ever ned to change main afterwrds or foul any plugs ?
use the choke to start ?

so your machine(s) NEVER rev up as the bowl looses gas ?
still not convinced that fixes any real problem that may have or not have been ...convince me
just asking questions cause I want to understand more on your point / suggestion etc

nope my quad Never does this. Not everythings needs an explanation. and one thing. the only way a carb can suck air from the bowl, is if it sucks it from the over flow tubes, try putting on one of those carb line filters and that might keep it from sucking air in the over flow tube.

 

:huh: ...ok^
well I guess I'll leave my machines as is ...they all run great B)
& needs no additional tuning just for draining the carb bowl at end of day

 

Yah, see your point..... I honestly never touch the petcock unless they are going to be stored, for quite a while.

 

Yah, see your point.....

Glad to hear it ..others can do as they please
til someone can reteach me carbs or at least explain
something logical about a reason for thinking they know better than me
I will continue to go with what I know is best !

 

Well, that is an interesting point, I mean the only place the bowl gets air is from the vents, or through the needle to jet needle seal..... So if the pilot is no longer submerged in gas, it is pulling air from somewhere... Not sure that warrants a pilot adjustment though, since it will always pull air from somewhere, as I just mentioned....

 

:huh: ...ok^
well I guess I'll leave my machines as is ...they all run great B)
& needs no additional tuning just for draining the carb bowl at end of day

i didnt ask anyone to do any more tuning. just thought i would let the thread starter know how i fixed this problem.