Carb? By 89newbie (Read 788 times)

[89newbie]

HAving a problem with flat spots. then good. Ordering a new intake fitting, at the same time considering an 18 MM carb upgrade. Question is when I do the other things to the engine is this the carb I would want of a bigger one. Any help would be appreciated.

[Bashan]

How many ccs in your engines, that makes a big difference on what carb you put on. I'd first get the stock running right before you start throwing different parts at it, it doen't sound like it's malfunctioning that badly. Flat spots are a big red flag for vac leaks, check all your lines, intake manifold, and fittings, I had a bad coill cause the same problem once, you can ohm out a coil, it's in the tech section, but I like to keep a good coil around for testing purposes. Rich

[sprocket]

May want to check the CVT. It could be the pulleys are worn/grooved or the belt is slipping a little.

If it is truly engine power related other than the coil, the CDI capacitors can get lazy and the pick-up coil can miss a few beats...

Could even be as simple as a fuel filter. Many guys use automotive fuel filters and they suck on these scooters. Get one from a riding mower or generator.

It could be at higher RPM the fuel filter is not allowing enough flow and the float is running short on fuel every so often...I have seen it happen.
feels like a brief loss of power, but the engine is still running...

Could also be a weak vacuum on the petcock.. it will starve the gas flow for a few seconds too...especially at WOT

[Alleyoop]

To pinpoint what could be causing your problem, need a little more in detail what is happening. Does it Bog or hesitate when you give it throttle does the engine make a BOGGing sound or the engine runs good. Or when your riding it sort of lurchs forward and backwards OR when your riding the engine itself slows down and then speeds up.

Different ways the scooter is acting point to different things that need attention.
Alleyoop

[89newbie]

Apr 6, 2011 12:19:45 GMT -6 Bashan said:

How many ccs in your engines, that makes a big difference on what carb you put on. I'd first get the stock running right before you start throwing different parts at it, it doen't sound like it's malfunctioning that badly. Flat spots are a big red flag for vac leaks, check all your lines, intake manifold, and fittings, I had a bad coill cause the same problem once, you can ohm out a coil, it's in the tech section, but I like to keep a good coil around for testing purposes. Rich

have done it all. My thought is time to quit foolin with it beause Im changing exhaust to match. Time is money and if Im going there why not?

[89newbie]

Apr 6, 2011 17:08:51 GMT -6 Alleyoop said:

To pinpoint what could be causing your problem, need a little more in detail what is happening. Does it Bog or hesitate when you give it throttle does the engine make a BOGGing sound or the engine runs good. Or when your riding it sort of lurchs forward and backwards OR when your riding the engine itself slows down and then speeds up.

Different ways the scooter is acting point to different things that need attention.
Alleyoop

Not WOT its when starting out kind of like a closed choke. at about 5 to 550 then O.K. again.

[Alleyoop]

Do you let it warm up or does this happen when you take off when its Cold. Just sound like all you need to do is Adjust your Air/Fuel mixture, it is not running good at lower rpms.
Alleyoop

[89newbie]

Apr 6, 2011 21:39:33 GMT -6 Alleyoop said:

Do you let it warm up or does this happen when you take off when its Cold. Just sound like all you need to do is Adjust your Air/Fuel mixture, it is not running good at lower rpms.
Alleyoop

Air Fuel has the cap on it.

[Alleyoop]

Well, then your in a Pickle, no way to adjust your carb, suggest you get one with the Air/Fuel Adjustment open. They have them the exact carb as you have but with the Air/Fuel mixture screw available.
Alleyoop

[sprocket]

It could be plugged or it could be capped. If it is capped, then there is an adjuster screw under it. Need to drill a small hole in the cap and pull it out with something hooked.

If it is plugged then I would buy a new carb... but if you are running way lean adjust the throttle needle. Move the c-clip a slot or two toward the point...or put a small washer under the needle on the 'non-adjustable' needles. The aluminum pop-rivet washers work very well...

[89newbie]

Apr 7, 2011 11:43:34 GMT -6 sprocket said:

It could be plugged or it could be capped. If it is capped, then there is an adjuster screw under it. Need to drill a small hole in the cap and pull it out with something hooked.

If it is plugged then I would buy a new carb... but if you are running way lean adjust the throttle needle. Move the c-clip a slot or two toward the point...or put a small washer under the needle on the 'non-adjustable' needles. The aluminum pop-rivet washers work very well...

B]This is what I found pulling the needle. There was a slight little fold in the flange of the thin rubber top of the thinggie. Three groves snap ring on center. dropped ring to bottom then took some gas soaked the rubber thingie a while to get it good and wet and carefully and slowly resealed it br positioning properly and rubbed around and around with index finger. Once it looked uniform I installed the spring and top. Hit the start and instant start, rode it 10 miles. Top end better hills and I mean hills are now 4-5 MPH faster ( chinometer) Stopped several times and let it idle and the rpm fluctuations are gone, must have been that little bubble. Went to the barn late last night started it and it did what it was supposed to, no rpm up and down, left it run and all good. Started it this morning let it idle for 20 minutes still all good. Almosr forgot hesitation is gone. Now Im gonna tear the muffler apart and see whats up in there, LOL Mrs Newbie says Im a 9 year old with this thing rofl.