Stock carb mod

[Smoothe]

Nice mods Egor!

I have a few free days coming up, and a few engines I bought from a guy on Craigslist: (screamin' deal). This would be a good time to "Tear into them" cause that's what I bought them for: Mucho Modification.

I think I was semi-scolded here once by someone for "Tearing Into" my engine. I have since bought, built, and sold five of these little turds and have learned alot, (thanks to you guys and my mechanic friends). This is great information and I'm going to run with it....Its MY engine, I bought it with MY money, and I can do whatever I want to it.

Thanks Egor, & can you post more pics?

 

[ken murphy]

Hey egor I still have flat a flat spot on both of my bikes on the top end the raw engine is still slower than the the one I bought from spookey tooth they just won't stay rapt out,it goes in & out.They both have the carbs drilled that worked well thank's,I would like to figure it out,I still think it fuel,any Ideas?

 

[misteright1_99]

Main jet is too small.....

 

[Bikeguy Joe]

Nice mods Egor!

I have a few free days coming up, and a few engines I bought from a guy on Craigslist: (screamin' deal). This would be a good time to "Tear into them" cause that's what I bought them for: Mucho Modification.

I think I was semi-scolded here once by someone for "Tearing Into" my engine. I have since bought, built, and sold five of these little turds and have learned alot, (thanks to you guys and my mechanic friends). This is great information and I'm going to run with it....Its MY engine, I bought it with MY money, and I can do whatever I want to it.

Thanks Egor, & can you post more pics?

Dude! Some here tore into you for tearing into your engine!?! Here?

Are you sure it was here and not another site?

I agree totally, it's your engine to do as you see fit.

 

[Bikeguy Joe]

Hey egor I still have flat a flat spot on both of my bikes on the top end the raw engine is still slower than the the one I bought from spookey tooth they just won't stay rapt out,it goes in & out.They both have the carbs drilled that worked well thank's,I would like to figure it out,I still think it fuel,any Ideas?

Goes in and out? You mean pulls hard, then goes flat? That is usually fuel foaming in the float bowl, or the fuel flow is not enough to keep up with the demand at higher RPM.

 

[TexasDav]

Goes in and out? You mean pulls hard, then goes flat? That is usually fuel foaming in the float bowl, or the fuel flow is not enough to keep up with the demand at higher RPM.

I was thinking at one time building rubber motor mounts for my bike, but after my engine was just slightly loose it foamed the fuel and killed the power at higher speeds. So my thinking now is, if I isolate the motor with rubber motor mounts, it would let the motor vibrate more, causing even more foaming.

 

[mechanickid]

well that didn't work... i drilled a hole just like yours on page 1 maybe a tiny bit smaller, and now it only idles with the choke on, and shuts off if i turn the choke off unless it has more throttle. and even then runs really rough. i drilled some holes in my air filter but that didn't help... what did i do wrong? good thing i have an extra carb!

 

[captainrichhill]

I was hooked on this mod and was ready to start drilling right until MECHANICKID said it didn't work for him. What went wrong?? I only have one carb and would hate to be out of service until a new carb showed up.

 

[misteright1_99]

well that didn't work... i drilled a hole just like yours on page 1 maybe a tiny bit smaller, and now it only idles with the choke on, and shuts off if i turn the choke off unless it has more throttle. and even then runs really rough. i drilled some holes in my air filter but that didn't help... what did i do wrong? good thing i have an extra carb!

Sounds like an air leak to me. Are you sure you got the carb/ intake sealed up when you reinstalled? When you choke it the engine should die right away, sure sign of air from somewhere else......

 

[mechanickid]

yea like the hole i made to get air from the float. so now it needs more gas? does that mean i need to get a bigger jet?

 

[misteright1_99]

But that hole that you drilled is pulling a saturated mixture of air and fuel, and being soooo small, that should not be the problem, especially since you say the hole you drilled was smaller than .041 What size drill did you use to make the hole? I would check the jet to make sure there is nothing in it restricting the fuel flow if you are sure there are no air leaks. Then you could try a larger jet.

 

[ken murphy]

All that I can say is that after much comtemplation I took Egors advice after I tried ordering extra jets drilling them thinking that my motors were starved for gas opening up the the holes on the jets did nothing made it worse.On the other hand if you do it just like Egor says it will help. it helped both of my motors,both on top end and Idol.I was so convinced I drilled my third carb thats going on my OC schwinn chopper before installing the motor.

 

[mechanickid]

well i guess mine wasn't smaller! .0625 i know the jet is clean, and i cleaned everything else with compressed air. if it was just gas saturated air then it should run with the choke off. i drilled my hole a little to the right of where Egor drilled his, so its not at an angle and more in the center. was that a mistake? i dont see how it could make a difference...

thanks for the help guys

 

[ken murphy]

When I drilled the jet on my one engine,from what ever size it comes from the factory,thinking that my engine needed more fuel to .040 the motor ran like crap so Im thinking it's .025-.030 I dont know I dont have gauge pins to measure it.So the point is I dont think you can change it much so if you did drill the carb.0225 larger and not with the air flow 45' you may have made a mistake use a torch tip cleaner to open the jet,a little at a time. that monkey losend my plug and it blew out yesterday.

 

[misteright1_99]

well i guess mine wasn't smaller! .0625 i know the jet is clean, and i cleaned everything else with compressed air. if it was just gas saturated air then it should run with the choke off. i drilled my hole a little to the right of where Egor drilled his, so its not at an angle and more in the center. was that a mistake? i dont see how it could make a difference...

thanks for the help guys

The hole is too big. It is drawing too much air and fuel, probably mostly air if it runs with the choke on. I would solder it closed and redrill it at the .041 or leave it soldered closed. You can get the bits at most hobby shops, The drill desingnation size you would want would be #59 although I am sure a #58 or #60 would work fine......

 

[mechanickid]

thanks, that sounds good, i'll do that.

 

[misteright1_99]

Just make sure you take the carb completely apart, idle screw, float, float seat and needle, there might be some orings that could melt..
Good Luck........

 

[mechanickid]

thanks a lot

 

[captainrichhill]

Let us know how things go. By "us" I mean me. Thanks. Rich

 

[ken murphy]

Does anybody know if the coil C.D.I or whatever it is the little black box that the spark plug wire comes out of is worth up grading? Still can't get the rpms I want.