Predator 212 surging

[minibiksteve1234]

Just put predator 212 in neighbors bike. Stock 212 besides an air filter adapter and a 95 jet. Today was fire up.day. Got running and it's surging at full throttle you can see govonor arm opening and closing the butterfly. Engine rpm is 3860 to 3720 ish when it surges. He doesn't want to bypass govonor if possible he has a kid that rides it occasionally. How do we prevent the surging? I'm out of ideas

 

[Minimichael]

What rpm range are you trying to reach?

 

[ole4]

When the governor hits the adjusted rpm the motor will modulate the throttle and that causes a slight surging which is normal.

 

[Minimichael]

When the governor hits the adjusted rpm the motor will modulate the throttle and that causes a slight surging which is normal.

Ahh. So bumping up against the rpm limit it's set at. Maybe adjust to the next hole over?

 

[minibiksteve1234]

When the governor hits the adjusted rpm the motor will modulate the throttle and that causes a slight surging which is normal.

Right I understand how it works but the drive ability is not there. If we take off full throttle it surges and bucks just trying to figire out how to smooth it out

 

[BrownStainRacing]

Right I understand how it works but the drive ability is not there. If we take off full throttle it surges and bucks just trying to figire out how to smooth it out

Look up under the fuel tank.
See what hole the spring is in, and move it to the farthest right.
If it's too fast for the kid, turn the throttle stop screw in to slow it down.

 

[sparkwizard]

TRY THE STOCK JET>

 

[minibiksteve1234]

TRY THE STOCK JET>

With then new air filter it would only run on choke so that's why we changed jets

 

[sparkwizard]

Is the stock muffler still on it? What does the spark plug look like?
Did it surge before you added the air filter?

 

[SAS289]

Is the stock muffler still on it? What does the spark plug look like?
Did it surge before you added the air filter?

That's what I'm wondering. If you're going to run stock engine RPM why would you use an air filter kit? And then isn't a 95 jet .037"? There's no need for that big of a jet to run 3600 RPM.

 

[sparkwizard]

BINGO! I am curious about why it would only run on choke after a free flow air cleaner swap. Did it run with the stock air box? If so, look at the gaskets.

 

[Mr. Pink]

If you're going to run stock engine RPM why would you use an air filter kit?

Because it looks cool!
At least that's my reason.

 

[minibiksteve1234]

Look up under the fuel tank.
See what hole the spring is in, and move it to the farthest right.
If it's too fast for the kid, turn the throttle stop screw in to slow it down.

Thanks I'll try that

That's what I'm wondering. If you're going to run stock engine RPM why would you use an air filter kit? And then isn't a 95 jet .037"? There's no need for that big of a jet to run 3600 RPM.

Clearence. The original air.box wouldn't fit due to the size of the bike and we had to build a.spacer for the engine which made it too high for original air box.

 

[minibiksteve1234]

Is the stock muffler still on it? What does the spark plug look like?
Did it surge before you added the air filter?

No stock air box and muffler would not fit due to clearence issues. We bought a header pipe for it.

 

[minibiksteve1234]

BINGO! I am curious about why it would only run on choke after a free flow air cleaner swap. Did it run with the stock air box? If so, look at the gaskets.

Yes ran fine with stock air box when we ran it for the break in before it was mounted in bike

 

[minibiksteve1234]

That's what I'm wondering. If you're going to run stock engine RPM why would you use an air filter kit? And then isn't a 95 jet .037"? There's no need for that big of a jet to run 3600 RPM.

It would not run unless itnwas on choke. Came with a 95 jet with the filter adapter. I assumed since it would only run on choke that it needed more fuel. Maybe I'm wrong. Everything stock worked great when we ran it for break in before we mounted it to the bike

 

[minibiksteve1234]

No stock air box and muffler would not fit due to clearence issues. We bought a header pipe for it.

I'll have to pull then plug. It was the original plug with 1/2 hour break in on it.

 

[VeritableFox]

Because it looks cool!
At least that's my reason.

Time to throw in the "Well ackshually" on this. Dyno tests I've seen from gopowersports and rando youtubers have shown stock predators going from 6.5-6.6 hp up to 8.7-9.1 hp from a air cleaner/exhaust swap with a 95/98 jet still on the governor. So, if you're looking at an arguably massive HP upgrade for often less than $100 on an engine you can get on sale for $100, it's a really good way to go.

 

[Minimichael]

I say try jetting up. The intake and exhaust upgrades could mean it's running too lean once you're up in full throttle range.

 

[sparkwizard]

Intake spacer gaskets are leaking.