90 blaster won't rev

[Coreyrcox]

I've looked for cracks in the intake boot and couldn't find any. The carb doesn't leak any gas/oil mix.
I know not to run engines without filters. Just easier sometimes to leave it off, kick it over and flip the throttle to see if there is any progress. And right back off since there hasn't been.
I'll put the carb back together in the morning and see how it goes.

 

[Herpderplol]

intake boot is one of 6 places this simple motor could leak...

 

[Coreyrcox]

I've looked for cracks in the intake boot and couldn't find any. The carb doesn't leak any gas/oil mix.
And having the exact same issue with two carbs kinda seems odd to me. Maybe it is electrical(my first thought).
I know not to run engines without filters. Just easier sometimes to leave it off, kick it over and flip the throttle to see if there is any progress. And right back off since there hasn't been.
I'll put the carb back together in the morning and see how it goes.

 

[Coreyrcox]

It can leak at the crank seals ,intake boot, and reed cage. Those are the only four I can think of....

 

[Herpderplol]

base and head gasket
i counted the seals as 2
spark plug (really bad if it leaks here haha)

technically more, i counted reed to cylinder and boot to reeds as one

 

[Herpderplol]

leak test it and you will know. is there a green paper gasket on the bottom?

 

[Coreyrcox]

Yes. Leak down test turned up ok.

I did another compression test as well and was running 138psi.

 

[Blaaster]

Header leaks,head leaks

 

[Coreyrcox]

Put the carb all back together today. Every orifice was cleaned and no blockages at all. Starts first kick and still no increase in rpm.

I checked for restrictions in the exhaust and there didn't seem to be any, Reeds looked good with almost no wear.

I still think its electrical, I'm leaning towards the stator.
I will be buying an oem stator next week I guess.

 

[jus_me]

YES! try an oem stator.. I have a strong feeling that it is one of the "R" stators.. Same if not similar problems with those stators..

 

[Coreyrcox]

It appears to be a "high out put stator, 75 watt"
Off eBay.

 

[harley1-5]

I put 3 junk stators]brand new]on my shee wouldn't run.Put on oem fired right up

 

[Coreyrcox]

I had a weak spark I thought when I first wired it up.

Messed with the grounds a bit and got a decent spark.
But still was questioning the output of it.

It is for are sucking plenty of fuel out of the carb while running. There is no way that it's fuel related now. I just don't think the spark is keeping up with the fuel input.

 

[harley1-5]

you still need to leak test

 

[Coreyrcox]

As in holding cylinder pressure?


Or?

I'm used to working on four strokes,
I can do cylinder leak down test in those, but idk if it is the same on the two strokes since there are really no valves...

 

[harley1-5]

there is a thread on here somewhere on how to do a leak test

 

[speedyslyder]

waste no more time get rid of stator and that orange coil
GET tested good used oem staor and coil,or brand new stator and coil

broken record

 

[Coreyrcox]

I have OHMd the coil and it is right in spec per the service manual.
I also checked the coil with a coil tester. And it's within spec.

The stator is what I'm going to replace. As it was what I originally thought was wrong with it in the first place.
I only get 3-4 volts out to the coil.

 

[speedyslyder]

ok well when the stator solve's 90 percent of the problem before you create another thread on how your blaster is acting up, then you will half to replace coil with oem to solved that problem
but yeah save as much money as you can i would to

 

[Coreyrcox]

I rarely post on forums asking for help.
I usually read as much as possible and try to figure it out myself.
I'm fairly knowledgable on electrical and mechanical(automotive mechanic for a living) issues.
I'm just not to familiar with two stroke motors and how they operate, I know the basic principals of it,
I've only had three yz250's.
Two cr250's, one trailblazer 250,
And one 250r
But all of them just needed Mainly mechanical work.

I've had multiple four stroke bikes, quads, and ATC's.
But this one really stumped me.
I have the coil tester that mounts to the wall and constantly supplies power to the coil and you move this knob farther and farther away until the spark stops, It got a good 5" away before it stopped sparking.
That's why I'm not going to buy a coil along with the stator.



I already had a leak down tester in my box.
After watching a video that was posted on this forum my engine is in fine shape sealing wise that is. It didn't budge after 2-3 minutes.