I did a few things.

1. New NGKs
2. Stretched Choke Springs
3. Pulled and cleaned carbs.
4. Shimmed needles to .04 (radio shack shims, measured to .02 each)
5. 3.25 turns front, 3.5 turns rear

Now the 5-7mph popping is gone.

I thought I would go 142/145 but Im happy with the results and see no reason.

 

Thats great !! Ive been chasing that low throttle popping myself. Might try lowering my clip a notch and see if it helps.

 

The slow speed popping really pissed me off. I ride around with my son in our cul-de-sac and rarely go over 8mph, plus tugging them around in the snow, you dont go very fast. Also I will be spraying weeds this spring so I wanted consistent slow and steady running.

I was screwing around on a gravel road today and got about 60mph top speed, Im 6.3 300lbs and have a windshiled so I think Im doing fine. [img]i/expressions/face-icon-small-smile.gif[/img]

That choke setup is kind of lame, I wish it just had a simple plunger on the carb side.

If you shim, I dont see any reason to look at the plugs. As I can only be enrichening correct?

 

dude by a jet kit. You will need to mess with the jetting if you put a pipe on to. Ive put a ton of kits on the praries and the instruction get you in the ball park. Rule of thumb i learned is to go one more clip than the instructions say with a pipe and header. and depending on the kit make sure you put the right jet in the right carb. Also test the runnability at 20 to 30 miles an hour. Ive had lots of probs in that speed range. I documented every kit i put on (what pipe what kit what year etc.) I now can put a kit on and dont have to mess with it any more. All i can say is its a good thing you dont have to take the carb off(with the right magic tools of course) to do it or i would have shot myself by now. As far as shimming the needles you need to do more than that. The carbs are so lean from the factory to meet emmsions that you have to back the mix screws out three to for turns to make a ega tester happy. all you'll do by razing the needles is carbon up the head. a kit is 70$ just do it.

 

Wooga, thanks for the advice. I wont be doing any other modding, so I think I should be kosher. I have used Dale Walkers/IVANS kits on motorcycles, and they are far more comprehensive than the atv 'kits'; from what I see in the atv kits you get an air filter, and some needles that you can change the height on. You dont get slide springs new needles, ect. Do you even get new mains in a K&N kit?

There are lots of guys on the board here running .04 shims and 142/145 mains, I havnt seen anything bad come about? Not saying it wont though. Also in my tinkering I have already solved the cold starting with the pilots, works great. 3.25-3.50

Can you explain in a bit more detail since these bikes are so lean from factory why shimming a needle will carbon up the head? Im not saying your wrong but there are a lot of people here NOT using 'kits'.