Problem with Mini Bike? Start it and it goes!

[Infidel Strong]

Hello,

Well I just rebuilt my mini baja, Cleaned the carb., engine, etc..
After putting it all back together I went to start the mini baja.

Gas is on and chock is on.
When I pull start it the engine revs up really high and starts to go a little bit. That is only when it is on choke, Last maybe one or two seconds and then it dies. So I am thinking maybe a new spark plug.

I checked the throttle cables they look fine, Look like they are working as usual.

Any help would be greatly appreciated.

Shelby,

 

[Infidel Strong]

Anyone???

 

[milo raptors]

hmm check the governer a spring may be jamed it may be runin lean ???????

 

[mgregg85]

This is exactly what mine did after I pulled the governor, my throttle was stuck wide open. Check and make sure that your throttle is free to move and isn't stuck or sticking in the open position.

 

[Strigoi]

which engine are you running?

give it more than 2.5 hours before starting with the anyone? stuff. this isn't the fastest moving board out there.

 

[Infidel Strong]

Well I think I need new linkage and carb.

Looking at probably around $60.00 or so there.
A good friend of mine has a Greyhound 6.5 HP Horizontal Shaft Overhead Valve Gas Engine. He said I could have it for $85.00
http://www.harborfreight.com/cpi/ct...cpc&zmam=33951326&zmas=12&zmac=112&zmap=66015

I could figure out to take the TAV2 off the other engine and put in one this one correct?

It is brand new in box.

Should I go for it and throw it on the mini bike and set the other engine aside?

 

[milo raptors]

well what engine is on there now a 6.5?

 

[minibikedude]

Is your current engine new or used. I would think that if the engine has low hours you be better to find the problem and fix it. If it is trying to speed up when start it something is not set up properly either in your linkage or you idle speed set screw could be turned in to far. The engine that comes on those has a lighting coil on it ,I would try and keep that engine on it. Maybe someone on here that has one with the stock engine could post a picture of the stock linkage set up. Picture are worth a 1000 words.

 

[Strigoi]

if you're currently running the stock engine the 6.5 won't just bolt in. you'll need to drill/slot new holes for it to fit. you could also get the engine plate from cjtmini (member here) which makes it a direct bolt-on.

 

[bucksboysdad]

I think you may have the governor spring in the wrong hole. Play around with it in different holes to see which one works best. I had it in the wrong one too after taking off the carb and cleaning it....

Are you sure you didn't over tighten the throttle cable? This would keep the throttle from going all the way back to the idle position.

 

[Infidel Strong]

Is your current engine new or used. I would think that if the engine has low hours you be better to find the problem and fix it. If it is trying to speed up when start it something is not set up properly either in your linkage or you idle speed set screw could be turned in to far. The engine that comes on those has a lighting coil on it ,I would try and keep that engine on it. Maybe someone on here that has one with the stock engine could post a picture of the stock linkage set up. Picture are worth a 1000 words.

A picture would help a LOT! Anyone have one.
Engine is new less than 8 hours on it. Bought the bike brand new.

 

[Infidel Strong]

if you're currently running the stock engine the 6.5 won't just bolt in. you'll need to drill/slot new holes for it to fit. you could also get the engine plate from cjtmini (member here) which makes it a direct bolt-on.

I don't have a Doodlebug, I have a Baja Warior/ Blitz. If the 6.5HP Baja motor is came with I am sure another 6.5HP would directly mount on there.

 

[Strigoi]

yeah, the 6.5 will bolt in no problem on those.

 

[Infidel Strong]

I am about to give up on the linkage on this engine but going to keep trying.

OK in this picture below ( Not my engine just showing you the part ) circled in red on the carb. there is a little black piece and it moves back and forth.

On mine it is set up backwards or something, It goes the other way. So when I pull on the throttle it stays there. The black piece needs to open and close as I pull on the throttle.
Confused? In really simple terms it is backwards so when I pull on the thottle it is already open :thumbdown:.

Does that little black piece need tightened or ???? :doah:

Any help would be appreciated. Trying to get it fixed before tomorrow because family is coming in town and they would love to ride it.

 

[minibikedude]

I think the engine in the Baja Heat/Warrior are similar to the Harbor freight 6.5hp clones. I went out to the garage and took some picture tonight of the new 6.5hp clone I just got, This is how the linkage was set up from the factory. I hope these pictures can help you out.

 

[Strigoi]

have you thought about picking up a cheap Mikuni? that way you don't have to worry about throttle setups since they use a dirt bike style setup. it makes life much easier IMO.

you will need a manifold though. you can either go with the AGK one or get a Briggs Animal one and modify it.

 

[Oldschool]

The bike is the MB165 and it probably had a Jin Dong clone from the factory. The throttle is cable opperated and moves the regular throttle lever on the engine.

If you moved the location of the governer spring from one side of the three holes ( used to adjust sensativity of the gov ) to the other this can affect the idle RPM. Some engines use different spring than others. Generator springs run at a higher idle for some reason but are the same length ( I don't know why ).

So try moving the spring from out to the holes further out on the govern arm and see if the idel speed drops. I have mine set to idle around 1500 rpm. I also run two springs one slightly longer and stiffer than the other to let the arm come all the way back and sit on the idle screw but when I twist the grip the stiffer spring lets me rev up to my top speed at 4700. I have a box of gov springs and no two seem to be the exactly the same. I had to try a few to the pair I use.

I had the same problem with my Lifan clone and just had to keep trying different springs and governer arm holes untill I found a combination that let the shutter close right down at idle and then pull all the way up to my desired speed.

There's also the rod that connects to you gov arm nd carb. You might have that in the wrong hole as well.

These are not very good governer the speed and sensitivty adjustments are not that easy to do and require you to take too many parts off. I think in the long run you might want to completely remove it