Problem with after market driven pulley on trail master

[Ryanhodge2715]

Brother there's a chance maybe my piolet jet was a little clogged wich made me thing those jets are to big, with It shuddering out the hole. That 95 I absolutely got my speed an rpms the highest she ripped! About two laps around my back yard ( 2 acre circle) then I got a little spudder (no where near as bad) but I be damn if it didn't start raining when I ran it the way it was. Thinking I need to just adjust the screw that I assume is the fuel screw with it being at the back of the carb going to the engine right? An maybe this will actually (not ****ing with you) solve my problem MAYBE

 

[bob58o]

Yes if screw is on the engine side it controls fuel. Turn in to allow less fuel, which makes it more LEAN.

Turn it out to allow more fuel, which makes it more RICH.

Out of curiosity, I asked chatGPT what the usual jetting required for gx200 clone with cone filter and 1” straight pipe with no muffler… to see how well these forums trained our future overlords…

here’s the AI response…

“
For a GX200 clone engine with an aftermarket K&N style cone air filter and a 1" straight exhaust pipe with no muffler, you’ll generally need to adjust the jetting to ensure optimal performance. Here are some typical recommendations:

1. Main Jet: Start with a size around 0.036" to 0.038". This helps to compensate for the increased airflow from the high-flow air filter and exhaust.
2. Pilot Jet: A size 0.020" to 0.022" is usually effective.
   “

 

[Ryanhodge2715]

I be damn. Just guessing with you saying the .85 equated to what like .32 in inches (just guessing didn't go back an look) the 95 is about where I need to be?

 

[Ryanhodge2715]

So between my Monday night buzz an me being dedicated I said **** the rain. An by farrr the 95 is doing great. Same thing tho, I only cut 3 laps by the last one I had some shuddering (no where near as bad as befor but definitely there). I'm hopeful to think with some tuning she will run good. But rain has picked up hear in south cackalickey to much for me to continue. I will be back tomorrow an give a update. An I can't say it enough thank you brother an to all the guys that helped along the way. I know this seems to be something I over looked. Idk what it is tbh but it WOULD NOT RUN last I used the dif jets.

 

[bob58o]

Who knows with China jets? I use a set of tiny drill bits and calipers. I don’t trust those markings on China jets to be accurate.

Could be a size 85 jet from any number of companies, could be 0.85mm, I never know which sizing they use unless I buy official jets.

1.00mm = 0.039”
0.95mm = 0.037”
0.90mm = 0.035”

But often a 90 jet is not 0.90mm exactly.
Some jets #85 might be 0.036”

 

[bob58o]

So between my Monday night buzz an me being dedicated I said **** the rain. An by farrr the 95 is doing great. Same thing tho, I only cut 3 laps by the last one I had some shuddering (no where near as bad as befor but definitely there). I'm hopeful to think with some tuning she will run good. But rain has picked up hear in south cackalickey to much for me to continue. I will be back tomorrow an give a update. An I can't say it enough thank you brother an to all the guys that helped along the way. I know this seems to be something I over looked. Idk what it is tbh but it WOULD NOT RUN last I used the dif jets.

Try a new coil. It’s like $15. Still sounds like fuel bowl not filling fast enough or the coil. Or test the one you have if you have a multi meter with OHM setting.

you suggested the ignition coil when this started when you said the “Stator” was bad, then I suggested it, then I suggested it again, then others suggested it.

If you don’t have digital multi meter, that might be a better use of the $15… but still may end up needing a new coil.

These are $10. Used to be free gifts at Harbor Freight.

 

[bob58o]

Or try the old flywheel. Maybe the magnet on $30 flywheel isn’t working the way it should? Not sure how a magnet wouldn’t work right, but who knows?

Both coil and magnet don’t work as well when hot.

 

[bob58o]

Spark plug type?
Spark plug gap?

Wrong gap, or wrong type adding more resistance and heat in the ignition system?

Wrong heat range?

 

[Ryanhodge2715]

I'll have to wait till Thursday but I'll get one. But the 95 with fuel screw backed way out has my speed back for the first time I didn't clock it but atleast 30 ish. But I can still tell it has a little more in it I feel like.
It will idle with the screw backed out like I got it. But after I ride an go to slow down it kills out. Like it's to much. I'm assuming backing the screw out affects the piolet jet phase as well an it's to much for the low side but great when it kicks to the main jet. I could be wrong but almost thinking I need a little bit bigger tbh. I still got some spudder man... the thing hauling *** on my first run down the road then the spudder still but it sounds great to begin with. Then I slow down it kills out. I crank it right back up an floor it an the spudder is gone for about the same amount of riding then happens again. An I just hand tight the spark plug I have not used feeler gauge on it once. It has a thin spacer under it though?..

 

[bob58o]

Backing out the fuel screw all the way implies that’s a larger pilot jet would be better.

You want the fuel screw in the middle.

If the fuel screw is most of the way in, a smaller pilot jet would be needed.

If the screw is most of the way out, a larger pilot jet is needed.

ideally a correctly sized jet would be closer to the middle, not all the way in or out.

I don’t remember what a good setting is…
Something like lightly seat the screw, then back out like 1.5 - 2.5 full rotations?

 

[bob58o]

How is the primary clutch / driver unit?
This thread is titled ”Driven Unit” something or other. But wondering about the DriveR unit.

When the engine dies, can you push the kart freely or does the driveR unit seem stuck open?

 

[bob58o]

Lastly, the pilot jet should have a couple of O-Rings… you might want to inspect those to see if missing or damaged.

I assume you already learned how to remove the pilot jet?

 

[Ryanhodge2715]

Backing out the fuel screw all the way implies that’s a larger pilot jet would be better.

You want the fuel screw in the middle.

If the fuel screw is most of the way in, a smaller pilot jet would be needed.

If the screw is most of the way out, a larger pilot jet is needed.

ideally a correctly sized jet would be closer to the middle, not all the way in or out.

I don’t remember what a good setting is…
Something like lightly seat the screw, then back out like 1.5 - 2.5 full rotations?

Yeah sounds good, but I'm not sure I always just seat them in there never tried backing them out. An yeah the driver (clutch) is good only about 1month or so old. Was originally asking about the driven pulley I got. Had to use grinding compound to work it down on there. An yes I removed an cleaned the pilot jet an it was all in good shape. But it idles fine and takes off good with no hesitation. So I could be wrong but in my mind just changing my main jet to a larger size wich will help in my main jet phase (1/2 throttle n more) so I won't have to compensate so much on the adjustment screw wich I'm guessing affects both phases overall. In doing so maybe stop the dump of Gass when throttling back down? Also she spitting pretty good flames now. That I sign of to rich or normal for straight pipe?

 

[Whitetrashrocker]

Alright. You have a running engine for the most part. Now your getting into fine tuning.
Now you need to start reading the spark plug.
With a clean plug. Get to full throttle and run it for a bit and then kill the spark and coast to the garage. Pull the plug and see what it's telling you.

 

[ezcome-ezgo]

 

[bob58o]

This video shows a good way to do the testing that WTR mentioned. This guy cuts up the plug to get a better reading after the test, but I posted it just to show how to conduct the test.

I still think it’s best to get the pilot jet dialed in first before the main jet. A micro drill bit set with sizes 61 - 80 is in the range you would want IIRC. I think it only goes up to 0.039” but should cover 0.019 - 0.022” range for the pilot jet. Kit with these bits and a hand twist drill are fairly cheap.

 

[bob58o]

I’d say some flames from the exhaust doesn’t necessarily mean too rich with straight pipe. And when letting off the throttle with a straight pipe, you might hear some pops from after-fire in exhaust. (Is after fire the right word? Not backfire in the intake. After-fire in the exhaust? Sorry brain fart.) But I think this is normal too, to a certain point.

 

[bob58o]

so I won't have to compensate so much on the adjustment screw wich I'm guessing affects both phases overall.

No.

Fuel screw is for idle / pilot circuit only.

If the screw is almost backed all the way out to get the engine to run best with a certain PILOT jet, then that PILOT jet is too small.

The fuel screw should have little to no impact at 1/2 throttle and above.

 

[Ryanhodge2715]

No.

Fuel screw is for idle / pilot circuit only.

If the screw is almost backed all the way out to get the engine to run best with a certain PILOT jet, then that PILOT jet is too small.

The fuel screw should have little to no impact at 1/2 throttle and above.

Ok it definitely seemed to run bit quicker to me. But if that's the case wouldn't it be sluggish out the hole an maybe even give me shuddering then if it was to small/lean? Personally it didn't seem to affect my idle really at all an definitely didn't affect my initial take off. Only when I get back off the throttle it's noticeable.i have a few jets to play with an I have what I know as a torch head cleaning set of tiny files gonna look an see what they are labeled as an if there is one small enough to use that for today

 

[bob58o]

Ok it definitely seemed to run bit quicker to me. But if that's the case wouldn't it be sluggish out the hole a maybe even give me shuddering then if it was to small/lean? Personally it didn't seem to affect my idle really at all a definitely didn't affect my initial take off. Only when I get back off the throttle it's noticeable.i have a few jets to play with an I have what I know as a torch head cleaning set of tiny files gonna look an see what they are labeled as an if there is one small enough to use that for today

If the screw is all the way turned out, it’s the wrong pilot jet. I don’t have the energy to tune a carb over internet posts or explain the nuances of transition from one circuit to the next. There are YouTube videos that can teach this better than me.