212cc vm22 bogs

[bob geo kart]

Hello everyone, I just got my go kart done. Thing runs good till about 3000 rpm then it cuts out and bogs. I have a 196cc clone, the governor removed, straight pipe and a knock off 22mm mikuni. I got the clip closest to the bottom. I thought it jetting but this is how the plug looks. Any help would be appreciated.

 

[jmaack]

Same deal as mine. I never could get it tuned right. Plug also looks identical.

 

[bob geo kart]

Are you running a clutch or a tc?

 

[jmaack]

tq convertor.

 

[bob geo kart]

Same. Maybe the tc has something to do with it bc I got mine set on the most torque. I'm also running a 10t to 60t sprockets so I should get to about 35 to 40 mpg and I only get like 20. I also have 20 I wheels to.

 

[Denny]

Sure looks like It’s running way rich. Leaner jet is needed.

 

[bob geo kart]

i ran it with needle in 3 slot with stock jet and still bogs at around 1/2 to 3/4 throttle wont go full. It runs really good between idle and 1/2. i also put a 152 keihin jet which is a 130 on a mikuni.Runs the same. i just dont think it would be lean. Most ppl upgrade to 120 to 140 from what i been reading.

 

[jmaack]

Fwiw mine is a stage 2 ported head and billet shelf parts. I am using the racing autopilot plug which is cold from whatbim reading. for giggles yesterday I applied choke halfway and it didn't have as much bog and the center electrode was clean. I am going to order some jets and test out but it is going to be in a week or so as my daughter arrived this afternoon. so no minibikes for a while. I like you have a hard time believing I'm running lean and am just about to throw the carb in the garbage.
I will stay tuned to what you find.

 

[bob geo kart]

Ok. Keep us updated.

 

[madprofessor]

Black and sooty plug means running rich already, jetting larger won't help. That bogging at higher rpm sounds like either a fuel starvation problem (fuel filter, pump, float hanging, etc.) or a timing issue, which is my guess, not enough timing advance.
jmaack: My performance guy says that racing plug is great for dragstrip or track racing, but just putting around with it can foul it in minutes.

 

[jmaack]

Black and sooty plug means running rich already, jetting larger won't help. That bogging at higher rpm sounds like either a fuel starvation problem (fuel filter, pump, float hanging, etc.) or a timing issue, which is my guess, not enough timing advance.
jmaack: My performance guy says that racing plug is great for dragstrip or track racing, but just putting around with it can foul it in minutes.

good to know. I will try a different plug.

 

[bob geo kart]

So spark or valve timing advance?

 

[madprofessor]

??????? Don't know the first thing about valve timing, far as I know when the camshaft comes around it's the cam lobes that tell the valves when and how to open and close.
I was referring to ignition (spark) timing advance not sparking off the mixture soon enough to get a good burn of the mix. Checked with a mechanic I trust (takes care of my van) and he agreed that retarded timing can cause poor burn, black plugs, and failure to freely get higher rpm on the motor (bogging).

 

[Denny]

We do not use the term “retarded” any more as it is offensive. We use “advancely challenged”.

 

[Bansil]

I am going to order some jets and test out but it is going to be in a week or so as my daughter arrived this afternoon.

Congratulations

 

[madprofessor]

Making a "retarded" joke, or misinterpreting? Ignition timing gets advanced or gets retarded (ahead or less of TDC). Hope nobody really thought I was making the disgusting slang reference about mental progressions.

 

[bob geo kart]

I'm just gonna buy a Predator 212 and if it does the same thing just get a fly wheel key or a billet flywheel and it should fix it?

 

[madprofessor]

Yippeeeeeeee!!!!!!!!!! Bone stock reliability for $149!!!!!!!! Loads of fun motor without a single modification.