Tri-Z Carb Tuning

[Yamahauler]

I installed a new rod, ball, ajuster, fibres, metal plates, and spring in my clutch and it now works perfect. But now I have a few other problems.

There are a few carb problems that I could use some help figuring out.

1) When you rev it up, dump the clutch, it slows the engine right down and you cant take off fast. Its got absolutly no low end power.

2) Mid range is alright, but when you get to WOT, it breaks up.

3) First, second and third gear will not wind right out, its not until you get to 4th it will wind right out.

4) Very low idle (I'm just going to try and ajust the idle screw)

It had a 490 main in it earlier today and that was even worse, I fouled my plug, so I went down to the only other jet I have right now which is a 480. I'm going to order some more main ones, any suggestions on which sizes?

Everything is stock except for a Cobra exhaust with blown baffles (I need a new pipe)

I am going to try the Blue Marbel oil I have next fill up, and I hear its supposed to richen it up.

If someone could help me out with this, It would be great

[Yamahauler]

I didnt do an "official" plug chop, I only had one extra plug and the hardware store was closed. But I took it for a small rip and checked the plug, half of the insulator was black, the other half had nothing on it.

[straight pipe]

i'm wondering if it is muffler related. i heard if your 2 stroke runs out of power you should burn the exaust out...but there again i never owned a 2 stroke trike or dirt bike.

[TimSr]

Start with some clean plugs and good plug readings, but with the stock setup and Cobra pipe, your probably going to find its too rich. You didnt mention what mix you currently run, but I always found stock jetting somewhat on the rich side with the Cobra and the stock pipe, as well as the DG pipe. I also always ran the needle at the leanest setting or lowest position but left jetting stock and tolerated it being a little rich. With Blue Marble expect to drop jetting even further unless you are currently running a Castor type oil like Maxima. I ended up with 420's in both of mine, and its a little dark but runs perfect.

[Yamahauler]

I'm going to order a DG silencer. I was thinking of ordering 470 460 450 440 430 420 jet sizes, Do you think I'd need to go all the way down to 420 to run blue marbel, is it worth ordering a jet that small?

[TimSr]

I think thats a good selection of jets, especially if you are ordering them, and cant run down to the local shop for a couple more if needed. When I got my 420's I was looking for 440's but they didnt have them. I got 420's with the intentions of drilling them out, but after trying them, and doing plug checks, I was right where I wanted to be.