Idle problem...please help

[Mrknobblies]

So i have a mini baja and i recently purchased a stage one performance kit. of the kit i have installed a new carb with 0.37 jet and bored out tube, air filter and header pipe. i had to install a new bracket for the throttle return spring and i dont know if i messed something up with the springs or its something to do with the carb. the thing only starts on full choke and when it starts the idle is really high (like she'l take off with no throttle) also its like the idle is "pulsing" quite aggressively as it goes through the revs. When i take it off choke it dies and refuses to start with less then half choke.
Is this the idle screw, Is something off with the gov/ return spring? Any suggestions would be greatly appreciated!
Ive attached some pics.

 

[TheDullCarbide]

I don't think this would be the idle screw's fault. The pulsating tells me something is off with the idle mixture. I can't load your pictures for some reason.

 

[Mrknobblies]

I don't think this would be the idle screw's fault. The pulsating tells me something is off with the idle mixture. I can't load your pictures for some reason.

Bummer you can't load the pics, how do you suggest I fix the idle mixture? If that's the issue

 

[TheDullCarbide]

Bummer you can't load the pics, how do you suggest I fix the idle mixture? If that's the issue

Looking at my Greyhound, the adjustment seems to be at a right angle, below the head of the idle speed screw. I've also heard people say it is on the left side of the carb, in the flange that bolts up to the intake port.

Other questions:

Do you still have the governor in? If you do, try starting it up, hold the governor arm closed, and see what happens. Wouldn't be a bad idea lifting the back tires off the ground.

Try copy/pasting the pictures in your next post. It would really help if I could see the linkage.

Ty

 

[Mrknobblies]

Looking at my Greyhound, the adjustment seems to be at a right angle, below the head of the idle speed screw. I've also heard people say it is on the left side of the carb, in the flange that bolts up to the intake port.

Other questions:

Do you still have the governor in? If you do, try starting it up, hold the governor arm closed, and see what happens. Wouldn't be a bad idea lifting the back tires off the ground.

Try copy/pasting the pictures in your next post. It would really help if I could see the linkage.

Ty

Yup governor is still in okay hopefully this works

 

[TheDullCarbide]

Hey it WORKED! Just took 10 minutes to load. Crazy good picture quality.

Couple things:

The choke lever is going to pop off it's shaft when you ride. Either get a hold down bracket or put it in your pocket when you ride.

I looks like the throttle rod (between the governor arm and the butterfly) is just sitting on top of the butterfly. I should be put locked between the two tab thingys in the butterfly. I'll take a picture of mine soon.

Did you drill out the emulsion tube yourself or did you buy it? I read somewhere that the whole point of changing it was to have one with less holes to increase vacuum...something like that. If the throttle rod doesn't fix it, try throwing the stock e-tube from the other carb back in and see what happens.

 

[TheDullCarbide]

Here are those pictures. I still rock the stock everything on this engine. That's going to change very soon.:shifty: I also rock the Craptacular 2002 Kodak that weighs almost 4 pounds.

 

[Mrknobblies]

Here are those pictures. I still rock the stock everything on this engine. That's going to change very soon.:shifty: I also rock the Craptacular 2002 Kodak that weighs almost 4 pounds.


Haha the craptacular kodak ain't too bad!
Okay I have fixed the throttle arm and locked between the black tabs (dunno how I missed that in the first place) and I installed the choke rapport.

The emulsion tube is after market and the 0.37 jet as well, I too think that one of these is causing the issue...why would it be the emulsion tube and not the jet?
When I installed them the jet was a little bigger then stock but the bored out tube was a lot different them stock.

Thanks for your help man, I really appreciate it.
P.s what's the mini bike? What you putting on her?

 

[TheDullCarbide]

Here are those pictures. I still rock the stock everything on this engine. That's going to change very soon.:shifty: I also rock the Craptacular 2002 Kodak that weighs almost 4 pounds.


Haha the craptacular kodak ain't too bad!
Okay I have fixed the throttle arm and locked between the black tabs (dunno how I missed that in the first place) and I installed the choke rapport.

The emulsion tube is after market and the 0.37 jet as well, I too think that one of these is causing the issue...why would it be the emulsion tube and not the jet?
When I installed them the jet was a little bigger then stock but the bored out tube was a lot different them stock.

Thanks for your help man, I really appreciate it.
P.s what's the mini bike? What you putting on her?

I wish this one was a mini bike. It's a 2004 Chinese Ty-Rail 2-seater gokart. The only reason I like it still is that it only weighs 180 pounds with the roll cage.

Yes the jet is bigger so you get more fuel at 3/4-full throttle. The emulsion tube takes care of 1/4-3/4 throttle the way I know it. How many holes are in the new e-tube?

As for the bike wanting to run away at idle, the throttle rod should have fixed that.

Ty

 

[Mrknobblies]

I wish this one was a mini bike. It's a 2004 Chinese Ty-Rail 2-seater gokart. The only reason I like it still is that it only weighs 180 pounds with the roll cage.

Yes the jet is bigger so you get more fuel at 3/4-full throttle. The emulsion tube takes care of 1/4-3/4 throttle the way I know it. How many holes are in the new e-tube?

As for the bike wanting to run away at idle, the throttle rod should have fixed that.

Ty

So I fixed the throttle rod and I replaced the bored out e-tube and nothing has really changed, it seems to be more steady and runs for a bit with full choke but the moment I open up it dies. The idle is also still high causing her to wanna take off...ive played around with the idle screw and that only seems to make the 'pulsing' stronger an faster or weaker.
Anymore suggestions?? I'm going crazy with this thing

 

[SAS289]

If you can't idle without the choke you should probably focus on the low speed circuit. Try to figure out why you do not have enough fuel to idle without the choke on.

Are the carb gaskets in the correct position not restricting air flow? Have you removed the pilot jet and blasted carb cleaner through it? Have you blew carb cleaner through the pilot jet air path?

Focus on getting the idle corrected first, then test for higher engine speed/throttle response operation.

 

[Mrknobblies]

If you can't idle without the choke you should probably focus on the low speed circuit. Try to figure out why you do not have enough fuel to idle without the choke on.

Are the carb gaskets in the correct position not restricting air flow? Have you removed the pilot jet and blasted carb cleaner through it? Have you blew carb cleaner through the pilot jet air path?

Focus on getting the idle corrected first, then test for higher engine speed/throttle response operation.

It's a brand new carb, new tube and jet.. I'm pretty sure I installed all the gaskets correctly, there is definitely nothing that I know of restricting air flow. What else could it be?

 

[SAS289]

Another thing I failed to mention was have you checked if enough fuel is even going into the bowl? Remove the bowl and turn the gas on. Is there plenty of flow? If not why not?

Even though it is a new carb you may want to go through the process on this video. Especially if you cannot return the new carb. Brand new doesn't mean there can't be an issue.

[video=youtube;kMw91fiIXNc]https://www.youtube.com/watch?v=kMw91fiIXNc[/video]

 

[FOMOGO]

It's a brand new carb, new tube and jet.. I'm pretty sure I installed all the gaskets correctly, there is definitely nothing that I know of restricting air flow. What else could it be?

Unmentioned as of yet is the plastic spacer. They have been known to crack and cause a vacuum leak.

It sounds like you are experiencing a vacuum leak with the choke making it run and no choke causes it to die.

But the gaskets installed incorrectly could be the source of a vacuum leak as well.

Doug

 

[Mrknobblies]

Unmentioned as of yet is the plastic spacer. They have been known to crack and cause a vacuum leak.

It sounds like you are experiencing a vacuum leak with the choke making it run and no choke causes it to die.

But the gaskets installed incorrectly could be the source of a vacuum leak as well.

Doug

What's the best way to find if I have a leak? What is the plastic spacer exactly? I thought that's removed for the after market air filter or is that another spacer/gasket?

 

[Mrknobblies]

Another thing I failed to mention was have you checked if enough fuel is even going into the bowl? Remove the bowl and turn the gas on. Is there plenty of flow? If not why not?

Even though it is a new carb you may want to go through the process on this video. Especially if you cannot return the new carb. Brand new doesn't mean there can't be an issue.

[video=youtube;kMw91fiIXNc]https://www.youtube.com/watch?v=kMw91fiIXNc[/video]

On second thoughts, watching this video has made me think I've mixed up the the 2 rear gaskets. I think I've replaced the old air bleed gasket (one with the little hole) with a new gasket that actually belongs behind the rear insulator (without the little hole.)
Could this be the problem??

 

[FOMOGO]

On second thoughts, watching this video has made me think I've mixed up the the 2 rear gaskets. I think I've replaced the old air bleed gasket (one with the little hole) with a new gasket that actually belongs behind the rear insulator (without the little hole.)
Could this be the problem??

Yes it could

 

[OND]

Yes it could !

 

[FOMOGO]

Yes it could

Yes it could !

What's the old saying..... Oh yeah, "Great minds think alike".

Doug

 

[Mrknobblies]

What's the old saying..... Oh yeah, "Great minds think alike".

Doug

Well it did!! We are running smooth as a whistle!
Thanks everyone I wouldn't have figured it out without your help...now for the next problem - brakes haha that little drum doesn't slow her down too well