Be careful with the K&N. This last weekend was very dusty, and we rode for about 3 hours without stopping. When I looked at the filter, it was caked with dirt. I took it off and washed it, but I found dust in the carb inlet. I just put on a new foam filter from the other guys, which I heard was better for my dusty conditions in the desert.

 

Good tip. And I did find a part # in this forum for "the other guys".

 

basseyl,

Not sure if this is what your looking for.

Automatic choke replacement with a Plunger Primer.

Step 4

Primer

SB.

 

I really do not think it is a choke poblem. Mine does the same thing and I have put a manual choke and modified the electric choke, but it still does not start in the cold. It is the carb. Basically, you need to find a replacement to fix the problem and that may not even do it. All I do is shoot the K&N filter a couple times with starting fluid and it fires right up and runs great. I have learned to live with it.

 

Just did a rejet of my 150 quad due to an air filter mod. I also had some issues with cold starts. Along with a very lean condition. Now my quad has the manual choke(fuel enrichment). I no longer have the cold start problems that I was experiencing. You may want to go up on your pilot(slow jet). My stock slow jet was a #35 I took it to a #40. The main was a #111 it went to #135. I had to shim my needle with two shims. The needle did not have slots cut into it, so I had to shim it. I did run into a problem with my pilot jet at first. The pilot that was in the carb was 23.5 mm (26 series) but when these carbs were originally made they had the 21 series slow jets installed in them. So I installed the 21 (28mm)series slow jet in mine. Try and go up one or two slow jets. Your cold starts should go away.

Here is the jet chart to go off of if you decide to rejet.
Your mains should be N424-36 or the 99101-393
Your pilots(slow jet)N424-21

Jet Chart

Carburetor Circuits
Air Screw = Idle to 1/8 Throttle
The Pilot (Slow Jet) = 1/8 to 1/4 Throttle
The slide valve = 1/8 to 1/2 Throttle
Jet needle = 1/4 to 3/4 Throttle
Main Jet = 3/4 to Full Throttle

Don't know if the info helps, but something to think about.

SB.

 

Hi everyone, Ive been reading this thread due to the fact i just bought a used 150 for my son 2 weeks ago. This has been a big help lots of good information. The first thing i did was get a new K & N installed,big improvement. Last weekend after about an hour ride the thing just stoped going, it runs good but wont go forward. Must be the CVT slipping, I have read the post about using belt dressing for better grip, do you think thats what i should start with? And should this thing be shifting gears or it only a stright drive?

 

It is a CVT tranny which means it is a constant velocity transmission( no gears). No shifting gears. Infinate gear ratio. The belt may be bad and needs to be replaced. Does it move at all? I would NOT recommend belt dressing because the cvt needs to be clean at all times.

 

Hey, thanks a bunch for all the info, I'll be all over it. Did you remove your choke assy or leave as is?

 

I left the choke alone. My quad has the manual choke. It operates off a cable. The set up is a little different than yours but with the manual cable I can control the amount of enrichment that I want. It works real well. Have not had any problems with it so far. Now only time will tell.

You can see the cable in my pics. The Pipe Reducer Pic has a good shot of it.


SB.

 

Thanks, thats what i thought. Is this going to be a tough job and where do I get a new belt? Ive seen posts about Patriot is this a parts supplier for the Yamoto?