Stock carb mod

[Biker Mike]

Hey dave, does the shaved piston skirt go on the intake side or both. If you shave it to much will it cause the engine not to start. I just re assembled mine and it will not hit a lick . It has good fire and is getting fuel. It just will not hit. Any suggestions would be appreciated. Thanks, Mike.

Got it going. Wires were crossed...Duhhh!!

 

[Egor]

Mike the piston skirt mod only goes on the intake side, you can leave the ends long and only carve a notch the size of the port in the center 1/4 up max. Round everything over, no sharp edges. Let me know how it works. have fun, Dave

Hey dave, does the shaved piston skirt go on the intake side or both. If you shave it to much will it cause the engine not to start. I just re assembled mine and it will not hit a lick . It has good fire and is getting fuel. It just will not hit. Any suggestions would be appreciated. Thanks, Mike.

 

[Biker Mike]

Mike the piston skirt mod only goes on the intake side, you can leave the ends long and only carve a notch the size of the port in the center 1/4 up max. Round everything over, no sharp edges. Let me know how it works. have fun, Dave

Dave, it worked great. It seemed to improve the overall performance. I did not notice a big increase in HP however it seems to run much smoother in all RPM ranges. It also seems to have increased the top RPM's. All in all I would recommend this MOD. If someone could post a step by step guide, it would be great. I did not have a camera at the time of my Mod. I think more people would attempt this with a guide to go by. Thanks for the help.

 

[Home-made J]

does anyone know the torque specs for these China motors? Also, Egor, the size of that hole..is that mm or in. I have down to 1/64th" (0.40mm) is that big enough?

 

[Biker Mike]

does anyone know the torque specs for these China motors? Also, Egor, the size of that hole..is that mm or in. I have down to 1/64th" (0.40mm) is that big enough?

Hi J, 1/64th is WAY too big. E-bay has a set of micro bits with a .039 bit that will work, Search Item number: 260288126783. What part are you needing to torque? Head bolts are 10 to 12 ft lbs. Hope this helps.

Here is another set of bits on e-bay. This is the set I have. Search Item number: 300259348928

 

[misteright1_99]

does anyone know the torque specs for these China motors? Also, Egor, the size of that hole..is that mm or in. I have down to 1/64th" (0.40mm) is that big enough?

When I did my carby I went to the local hobby shop, they carry alot of individual micro bits....

 

[Home-made J]

thanks for the torque specs on the head bolts...I'm gonna do some porting today and didn't want to over-torque...Thanks for the drill info. I might still drill the stock carb, but my buddy used to have a pocketbike/scooter shop and wants to give me a tuned pipe and performance carb to play with...the biggest upgrade I've done so far is getting a 34T sprocket from Kings! Went from 32mph top speed (at about 6k rpm) to 40 mph at 55k rpm, but I know with some porting and ignition I could get to 45mph no problem.

 

[Biker Mike]

thanks for the torque specs on the head bolts...I'm gonna do some porting today and didn't want to over-torque...Thanks for the drill info. I might still drill the stock carb, but my buddy used to have a pocketbike/scooter shop and wants to give me a tuned pipe and performance carb to play with...the biggest upgrade I've done so far is getting a 34T sprocket from Kings! Went from 32mph top speed (at about 6k rpm) to 40 mph at 55k rpm, but I know with some porting and ignition I could get to 45mph no problem.

Be careful if using stock head bolt studs. I hear a lot of people strip them out around 9 ft lbs. I would upgrade to better studs if you do a tear down.

 

[Egor]

Be careful with the 9 LB. that is a bit high. I never use a torque wrench on these little engines. I use as small of a 1/4 ratchet as I can find and just put a little Wallie on it, not to much. I also use a small amount of Silicone, and I mean small, just enough to make it shine. I always put the gasket facing the same way and the same top. Yes the .040 is in inches a 39 will do. I need to get a photo essay to show the way. Have fun, Dave

 

[Venice Motor Bikes]

I think I'm going to invest in a extra carb before I do any mods on my only one.

"BUT I'M NOT DRILLING MY JET!!! PERIOD!!!!!!!"

 

[Goat Herder]

Tork wrench the only way to go, as an active ASE mehcanic this is all I use

 

[ken murphy]

My motor seems like it could use more fuel at top end and the pipe has to much back pressure I'm going to make a ex.chamber I already orderd the extra stock pipe It' gona take a bit but i'm going to do it.

 

[Egor]

Well for top end that is the main jet, that's wide open throttle. The needle is for all the mid range. I drill the hole in the runner to introduce some mix to the idle. You can do it. If you ordered a pipe wait till you run it before you jet the carb. One trick I do is, I use the cleaning wires for a welder tip. I just file the jet a little at a time to see if I can get it where I need, so far so good its easy. Have fun, Dave

My motor seems like it could use more fuel at top end and the pipe has to much back pressure I'm going to make a ex.chamber I already orderd the extra stock pipe It' gona take a bit but i'm going to do it.

 

[ken murphy]

Heres the pipe I put together works well took away some vibration,seems to starve for gas still on the top end

 

[TexasDav]

great info

 

[ken murphy]

my third engine will be here on the 18 I want to take mt first motor apart eventhough its working fine I want to re seal the motor it seems to leak out the bottom of the cylinder at the gasket any suggestions to seal it? I also am going to fabricate another pipe for my second bike I sent pic's.I'm going to build a trike with the third motor. Do those boost bottles work? What do they do? I think i just figured it out da how to send the pic's.

 

[ken murphy]

after I drilled the carb it worked well so I drilled the other two I have seems to work well with the pipe I faricated. My first bike that I built goes 45 I'm ready for the race in april with spooky tooth,thank you for the tip.I bought a three wheeler & an oc scwinn chopper I'll send pictures when I getem done.

 

[Egor]

Glad to hear that it is working well. It would be an easy addition for the factory and make the little carb work better for Idling. I have a few with the Yamaha carbs on they work only just a little better. My favorite bike has the Happy carb and Ill leave it alone. Have fun, Dave

 

[ken murphy]

Tell Chuck to let the monkey try to pick up a plug fresh out of the engine a hot one he'll laeve it alone.Mikey gave one a lit ciggeret monkey was pissed!

 

[Egor]

LOL we could only stand that Monkey for about a month and we had to get rid
of it. We named it after Chucks mean brother Steve. But it was fun to have as a pet as we worked on our race bikes, it would run through the rafters and get into everything, our plugs were off limits but it would get them and then drop them from the, you guessed it ( rafters ) Have fun, Dave

Tell Chuck to let the monkey try to pick up a plug fresh out of the engine a hot one he'll laeve it alone.Mikey gave one a lit ciggeret monkey was pissed!