Won't start and has black fuel in exhaust pipe...

[dinkyguitar]

dinky put your bike on a trailer and take it to a place, where you can test it and ride it with the jetting , that i spoke off and maybe you need a little bit practice how to kickstart the 250 in the right way...   

Yep...I'm with you on that....That would be the best.

Just have to find "that place".

dinky,

[Foxx4Beaver]

I wouldn't ride it at all until you're SURE it's not suckin air somewhere...or you will fry it.

remember, you said you weren't sure how your 1st attempt went because you couldn't get a good seal, but it lost pressure quickly...secondly, you said the intake boot looked iffy...and third, you've said twice that the idle fluctuates up and down.

that's 3 tell-tale signs of an air leak...unless you don't care if it blows...then by all means, go tear it up!

[dinkyguitar]

I wouldn't ride it at all until you're SURE it's not suckin air somewhere...or you will fry it.

remember, you said you weren't sure how your 1st attempt went because you couldn't get a good seal, but it lost pressure quickly...secondly, you said the intake boot looked iffy...and third, you've said twice that the idle fluctuates up and down.

that's 3 tell-tale signs of an air leak...unless you don't care if it blows...then by all means, go tear it up!

I'm with you...the ride won't happen for a while. I was just agreeing with riding once I get these issues sorted. Plus it's cold, bikes still has parts that are not on....and I don't have a trailer or carrier for it yet.

I'd like to do a proper pressure test it also...no worries. I'm not in any rush.

dinky,

[motopunk]

I wouldn't ride it at all until you're SURE it's not suckin air somewhere...or you will fry it.

remember, you said you weren't sure how your 1st attempt went because you couldn't get a good seal, but it lost pressure quickly...secondly, you said the intake boot looked iffy...and third, you've said twice that the idle fluctuates up and down.

that's 3 tell-tale signs of an air leak...unless you don't care if it blows...then by all means, go tear it up!

I'm with you...the ride won't happen for a while. I was just agreeing with riding once I get these issues sorted. Plus it's cold, bikes still has parts that are not on....and I don't have a trailer or carrier for it yet.

I'd like to do a proper pressure test it also...no worries. I'm not in any rush.

dinky,

no mx-track near by you??

 what you can do before the next ride is to change all gaskets and seals, if there are still old ones. dont forget the little seal on the exhaust valve rod (right side of cylinder) thats often the location of air leak ..replace the intake boot!  so youre on the safer side.. 
you can do a very simple air leak test on the running engine... take brake-cleaner-spray to the outside of the running engine to all gaskets/seals where you mean, there could be an airleak.. if the engine immediately idles higher, you have found it...

i would need a video of the running bike, to see and hear how it runs and idles in cold and warm condition.

[dinkyguitar]

Update...

The day started out with me cursing  but ended on a surprisingly good note  .

I built a pressure tester:



The gauge if anyone is interested is a low pressure slime product you can get at pep boys for ATV tires. I unscrewed it and fitted it on the tee fitting. The only part I had to make was that plug on the right which consists of 2 pieces of 1/2in. aluminum screwed together with gasket sealer between to the two halves.

After pumping it up I traced an air leak I thought was coming from the exhaust port plug but was actually coming from the governor rod/rack. It would loose air pressure in a matter of seconds but could hold 3 psi pretty good.

After cursing some more, and researching I found out I had installed this part backwards.



After reinstalling and re-lubing, I added 6 psi. and after 12 minutes I only lost .5 psi.

I didn't think this would be possible with a motor that old, but hey, I replaced every seal and bearing I could find...

Also, that .5 psi. is because I have 2 small air leaks on each side of the reed cage. I had used gasket sealer on the intake boot, cage, but not on the gasket to cylinder surface, which is where the leak is coming from...That will most likely get fixed either with sealer, or a Boyesen RAD-12 intake.

I'm happy now...

dinky,

[Foxx4Beaver]

excellent!...I knew it had an air leak ...which would've also contributed to the hard starting.
use a small skim layer of yamabond on the reed cage gasket to cylinder...problem solved.  

[dinkyguitar]

excellent!
use a small skim layer of yamabond on the reed cage gasket to cylinder...problem solved.  

Yeah, that was my solution too...but under normal conditions, should you need to use sealer?

It seems like using sealer would be like "rigging" it to work.

And I've used yamabond exclusively on this build. Good stuff, as recommended here. Glad I went with that.

dinky,

[Foxx4Beaver]

It seems like using sealer would be like "rigging" it to work.

not at all...there's a few guys that use yamabond on the reed cage gasket...it's one of the critical points, as you just found out
I even use yamabond as thread locker on certain nuts/bolts/screws....it's more forgiving and holds better than thread locker in some areas.

[dinkyguitar]

Never thought of using it as a thread locker....good to know!

dinky,

[dinkyguitar]

So I'm able to start my bike consistently now.

I installed a bigger main jet and pilot, and replaced my worn kick start lever.

But I "believe" the issues I had starting it was my lack of knowledge starting a 2 stroke.

I now prime it by 3-4 slow kicks, find TDC, retract the lever and kick it like hell.

In the past, when I found TDC, I couldn't kick past that next compression stroke. My foot always stopped and I wasn't able to follow through.

Now with the new lever, and confidence that the lever won't break, I'm able to kick all the way through.

And today I was able to start it in 4-5 kicks, and it's about 20 deg. outside, so I think I should be good this summer.

Thanks again for all your help,
dinky,

[Foxx4Beaver]

right on Dinky...

yes, 3-4 slow kicks 1st is the key...some guys like to lean the bike over until fuel drools out the overflow tubes...I myself never understood why anyone would want to dump fuel on the ground every time they start a cold bike, when 3-4 slow kicks primes it the exact same way.
I don't even have to prime my 250...it doesn't matter if it's sat for 4 days, or 4 months...1 good kick, and it lights right off every time...it's a keeper!
My 500, 4 slow 1/2 kicks, then one good kick and it lights right off.
Not sure how much riding you'll be doing over the next couple months in 20 degrees ...it's only 6 degrees where I'm at ...but pay attention on how it runs, you may need to go a little richer, or a little leaner...the end of your silencer will let you know if it's rich, if it starts leaking black kucka and spraying your rear fender with black speckles....WOT plug chops will tell you what you need to know/do also.
Keep in mind also, you'll want to lean it out again in a few months once the temps start getting warm again.
Have fun and enjoy!!

[Foxx4Beaver]

But I "believe" the issues I had starting it was my lack of knowledge starting a 2 stroke.

I'm sure that played a role to some extent...but that air leak issue I suspected you had, played an even bigger role in the hard starting.

[treedodgingfool]

I'm a bike leaner, but it depends on the fuel you use. With Cam 2/Sunoco 260GT 110 race gas, when I roll the bikes out every weekend the float bowl fuel has already evaporated. So on goes the petcock, a quick lean over, put it in gear and rock back & forth about two times to charge the cylinder.  One or two good full kicks to get the 250, 300 or 500 fired after the drill (whether its 95 or 14 degrees out).  When we used pump, usually could just roll 'em out, give a couple of good kicks & fire right-up. 

[Foxx4Beaver]

yup, every one has their own starting preference...I used to run cam2 for years...and I still prefer it, there was a gas station 20 minutes away where I could get it right at the pump, then they suddenly stopped selling it because they didn't sell enough of it....then it became a pain in the a$$ to get around here. Luckily I live literally 200 yards from my Kawie dealer, and they sell the 5gal buckets of vp-c12. 

[dinkyguitar]

Not sure how much riding you'll be doing over the next couple months in 20 degrees ...it's only 6 degrees where I'm at ...but pay attention on how it runs, you may need to go a little richer, or a little leaner...the end of your silencer will let you know if it's rich, if it starts leaking black kucka and spraying your rear fender with black speckles....WOT plug chops will tell you what you need to know/do also.
Keep in mind also, you'll want to lean it out again in a few months once the temps start getting warm again.
Have fun and enjoy!!

Nope, no riding in this cold weather....just starting it every few weeks. I like to start my "key" equipment every now and then. Not really a big fan of not starting it for months, unless it's my 25 yr. old lawn mower, which starts first pull every time no matter what.

When I was in my teens I always rode things not matter what temp it was. Be it my moped on the ice lake, or the 73 Suzuki 350 2 stroke street bike my uncle gave me....but back then I had a place to ride and no one really cared what noise you made. Now it's different.

But I still have to rebuild my rear shock which drips every time I sit on it, front fork seals, grips, etc.

dinky,