Baja Doodle bug 97cc carb/governor problem

[allstar59]

I know this has been asked more than once but I can't seem to get this engine to run right. I bought this doodle bug on Craig list and the guy I bought it from said it ran before he took the carb off. He gave me the old carb and linkage in a plastic bag. I put a new carb on it and put the linkage where I thought it should go.
It starts and idles just fine but when throttling up the governor pulls the throttle back and it never really reaches full power. If I manually move the black plastic piece at the butterfly it runs perfectly. I'm stuck and don't really know what to do. I've tried putting a different governor spring on it, gotten rid of the springs and made direct links with paper clips. Nothing seems to work. I'm not sure about the top linkage inside the spring, I've seen pictures both with and without it and I've tried it both ways.
I know a 212 would be great but this bike is for a couple of 9 year olds that have never ridden before so I'd really like to keep it on the docile side for now. Any sugestions would be great. Here's a couple of photos of the linkage as I have it set up.

 

[OND]

Hey allstar, I'm fixing to run out to the shop ..and I have one of these engines on a bike....I'll snap you a couple of pics and post them for you in a little bit.

 

[OND]

Hope these help !

 

[OND]

 

[allstar59]

Thank you for the pics.Aside from return spring being hooked in a different hole everything looks pretty much the same. I'll keep messing with it

 

[minikenny]

I know this has been asked more than once but I can't seem to get this engine to run right. I bought this doodle bug on Craig list and the guy I bought it from said it ran before he took the carb off. He gave me the old carb and linkage in a plastic bag. I put a new carb on it and put the linkage where I thought it should go.
It starts and idles just fine but when throttling up the governor pulls the throttle back and it never really reaches full power. If I manually move the black plastic piece at the butterfly it runs perfectly. I'm stuck and don't really know what to do. I've tried putting a different governor spring on it, gotten rid of the springs and made direct links with paper clips. Nothing seems to work. I'm not sure about the top linkage inside the spring, I've seen pictures both with and without it and I've tried it both ways.
I know a 212 would be great but this bike is for a couple of 9 year olds that have never ridden before so I'd really like to keep it on the docile side for now. Any sugestions would be great. Here's a couple of photos of the linkage as I have it set up.

It sounds like it is working right. The governor is trying to maintain a speed or rpm, not a power level. If the engine isn't under much load it won't open the butterfly very far at full speed.

Under a heavy load it will open the butterfly all the way and might not be able to maintain full governed speed. :shrug:

I'm sorry if you already know this, but from your description it sounds like it is working, and your pictures look like it should work. :thumbsup:

 

[OND]

Also it looks like the little spring in the back on the govenor lever is in the second hole down from the top and yours looks like its in the third hole down.

 

[allstar59]

Thanks for the input guys! Minikenny I really don't know that much about it, just enough to screw things up. Thank God for google, youtube , and oldminibikes.com to come to the rescue. Next time the kids come over I'll toss em on it and see how it does.

 

[Raskin]

. this is what I do..the paper clip is going from thottle to governor arm..the top pointer is where I put a weak return spring that is attached to the muffler cage..this setup will not allow governor to pull throttle back so it won't limit revs.. you can limit revs by using a throttle stop..if your stop screw there..I threw mine away..use this at your own risk.. when mine almost screams..I let off throttle

 

[minikenny]

View attachment 88942 . this is what I do..the paper clip is going from thottle to governor arm..the top pointer is where I put a weak return spring that is attached to the muffler cage..this setup will not allow governor to pull throttle back so it won't limit revs.. you can limit revs by using a throttle stop..if your stop screw there..I threw mine away..use this at your own risk.. when mine almost screams..I let off throttle

He didn't ask how to bypass the governor. :001_rolleyes: It's for some 9 year old kids who have never ridden before.

 

[Raskin]

hehe..It just seems more responsive overall..throttle stop can be used says i

 

[chipper]

Save yourself a lot of heartache and get the 212 , you can set throttle stop scew perfectly where it will give just enough rpm's to engage the clutch , it'll run great , start with one pull for years if taken care of and when the kids aren't around you can back that screw out in 2 seconds and have some big boy fun ! Good luck .

 

[allstar59]

Thanks everyone for all the input. Since I already have the engine i think I'll try Raskin's suggestion. If that doesn't do it then it just makes sense to put a 212 on it and slow it down like chipper said. I really don't have that much small engine experience so I'm learning as I go. I have an old Briggs 5hp flathead that came off a Manco go kart that needs a carb rebuild so if that works it might be an option also.

 

[chipper]

You'll get it Bro , it's a learning curve that comes quickly , lol !!

 

[minikenny]

:laugh: Well it certainly is the wild wild west here anymore :2guns:

Just a few months ago, giving instructions to disable the governor without a stern warning to upgrade the rod and flywheel was a huge no-no. :shrug:

I just hope the 9 year olds don't get hurt. :doah:

 

[allstar59]

I think it'll be ok. I went ahead and did mod the linkage and it didn't turn it into a raging beast. It still just goes putt...putt.,putt. It really didn't bypass or disable the governor because it still retards it somewhat but it did improve the performance but even wide open the rpm's are still well under what I would consider over revving and I certainly wouldn't do any thing that would hurt the kids.

 

[Fisher1983]

Assuming your governor system is working properly, clean the crap out of the carb and jet it. What I did on my Dirt bug was buy a pin vise handle and a set of wire drills #61-80. I found the bit that fit the stock jet and then drilled it out with the next size up. The pilot jet, which is pressed in below the idle speed screw, took the smallest bit (#80.) I just kept spinning the bit in the pilot jet until I felt satisfied. I put it all back together, set the air bleed screw on the right side of the carb to 3.5 turns out from seated, and it runs excellent. My carb stock is the Huayi version which I feel is better. With a little tinkering and patience it can run well. Post some pics of your carb!

 

[Fisher1983]

Id also like to add that the 2500 stall clutch spring from Hot Rod Mini Bike helped a bit. My engine also has a header and I burn ethanol-free gasoline from the local marina. All these little tricks helped my bike immensely and that says a lot considering my bike is still brand new...it had 3 hours run time when I bought it last month.

 

[PennsyDutchman]

Assuming your governor system is working properly, clean the crap out of the carb and jet it. What I did on my Dirt bug was buy a pin vise handle and a set of wire drills #61-80. I found the bit that fit the stock jet and then drilled it out with the next size up. The pilot jet, which is pressed in below the idle speed screw, took the smallest bit (#80.) I just kept spinning the bit in the pilot jet until I felt satisfied. I put it all back together, set the air bleed screw on the right side of the carb to 3.5 turns out from seated, and it runs excellent. My carb stock is the Huayi version which I feel is better. With a little tinkering and patience it can run well. Post some pics of your carb!

++
I had similar problems with my parade bike and after cleaning the jets it runs way better. Same carb on the stock Baja engine.