Modern Buddy

My roughhouse seems to be running too rich

when I first start it, the first couple take-offs are good and peppy.

but from then on it bogs badly at low and mid speed and takes forever to get up to speed.

coming out of a turn is a joke.

are there some carb adjustments i need to be making?

air / fuel mixture screw

mine has come loose and worked it's way out in the past.
easiest thing to do is download the service manual, set it to stock then adjust

+1

I've also seen roller weights act somewhat similar, but it's unlikely.

where can i find the manual?

@ray // thanks

no problem

the manual is crap but it'll show you where the screw is. You'll have to pull our seat off to make it easier to get to.

OK, so i tweaked the mixture screw from all the way stopped down to wide open and everything in between and it has almost no effect on the performance at either end.

Does it matter that I have the Prima pipe on there?

How many miles do you have on the machine?

If it was running good and you have made no changes the problem could be in the transmission. A poorly "shifting" clutch could cause these symptoms. (as mentioned above)

Ray Knobs wrote:How many miles do you have on the machine?

If it was running good and you have made no changes the problem could be in the transmission. A poorly "shifting" clutch could cause these symptoms. (as mentioned above)

1500 miles, got it in July.

i have been told that it may need a different jet to get it to perform right??

Did you just put the pipe on and now it doesn't run right or was the pipe already installed and it used to run correctly?

In theory when you install a pipe you need to install (or drill) a bigger "slow" jet. Although scooterworks claims this pipe was designed to need no jetting change.

You left the pipe out of your 1st post. It's kinf of a big piece of the puzzle. Was the pipe on before the problem or is it the problem.

Ray Knobs wrote:Did you just put the pipe on and now it doesn't run right or was the pipe already installed and it used to run correctly?

In theory when you install a pipe you need to install (or drill) a bigger "slow" jet. Although scooterworks claims this pipe was designed to need no jetting change.

You left the pipe out of your 1st post. It's kinf of a big piece of the puzzle. Was the pipe on before the problem or is it the problem.

let me back up to the beginning: I bought it used (300 miles) and it had a pipe and a carb that according to the dealer i bought it at was jetted better for the pipe. This dealer is not near my house.

Within 100 miles of riding it, the acceleration started bogging badly. I took it to the local dealer to see what was up and they put a new carb on it which is on there now, and it is stock, no jetting. the new carb runs better than it did when the old one went bad, but not nearly as well when it was working well.

but the performance is consistent although bad.

It takes between 40 and 60 seconds for the motor to finally wind up and clear out and find any power. a slight hill or headwind makes it even worse.

the thing that bugs me is that the first couple of starts when it is still cold are awesome, and then once it is warmed up, it sucks.

I de-restricted the tranny a couple days ago. didn't effect anything other than give me more top speed, which is to be expected.

I am approaching the point where i can't be that much of a help to you anymore as i have not had these similar problems to solve on my own machine yet.

So take this with a grain of salt, this is what i would try to do before giving up and taking to the dealer (it's cold as hell here and warranty work is free)

I would start my sticking a larger jet in. I don't know what the 50cc stock size is. There are couple guys here that will know. They'll chime in with there set ups that work. Buy the next two sizes up and experiment. Jets are cheap, can't find larger. Get another stock size and a proper drill bit to enlarge. The manual you downloaded should show where the jet goes.

This part may be totally wrong but makes sense in my mind. When the engine is cold the electric choke on the carb enriches the mixture, (you run good at the low/mid end) When the engine warms up, the choke goes off, and your back to your loosely mixture. (need more fuel = bigger jet ??) Your top end has been unaffected by all of this because it is controlled by a separate jet.

Hopefully someone else will post and tell me i am full of crap or close. Hopefully this gets you pointed in the right direction

My guess is your auto chocke is f'd up....

nissanman wrote:My guess is your auto chocke is f'd up....

I know mine is f'd. A new one is on order but it failed in a way that it doesn't turn on so it's like not having a choke at all at start up.

The shop that changed your carb may not have hooked it up right (but probably not). If it runs good cold, and acts up as it gets warm your choke might be staying on.

is the auto choke something i can change?

Probably. I haven't messed with mine yet, it hasn't broke.... yet. There's still time for mine.