When my DS is under a load (RPM’s low coming out of a corner or climbing a hill) it stumbles. If I try to give it more throttle it gets worse. If I back of the throttle some and easy into it or down shift it pulls like crazy.

The plugs look good
(hard to get a good reading, lots of snow and no wide open stretch)

I am running a dyno jet 180 main, needle on 2nd clip just like the instructions said mixture screw is 2.5 turns. The Engine is stock except K&N filter and Supper Trap end cap with 6 disc.

Does this sound like a jet needle problem? If I richen it up it gets worse


Thanks

 

That settings sounds about right.

What altitude are you running the DS? We are running similar setups at 5000 ft above sea level. We actually use 185 Dynojets. The DS's have either no lid on or have bigger intakes on the airbox.

Try running the DS without the intake pipes connected to the airbox or even without the lid.

If it runs better without the lid or the intake pipes, then the min jet might be a size or two to large. Try going a size or two smaller. If it is worse without the lid, try going up a jet size or two.

Let me know if the problem gets worse or better.

 

Sounds rich to me. Try lowering your needle (raising clip) and/or smaller main jet. 180 sounds like a huge main jet for no real mods....

 

180 is what I use. it works great. what did you do to richen it up that makes it worse? the only thing different from yours to mine is, I have my mix screw at 3 1/2 turns out. and a different endcap.

 

This was the first time I rode it since the end cap mod. Before that I ran the stock exahust with the stock main jet and the stock needle on the last clip and it ran good. I will try and move the needle down a step. It's just weird that being rich would cause it to act like that.


I found a DJ to Mikuni cross reference and it looks like the DJ 180 main is only a little bigger than the stock main jet (is this true?) if so the next step down would be the stock main. If thats what it needs than the end cap mod didn't do much for flow.

 

yea, thats right. thats why I am still on the fence about being to rich. allthough, the needle is thinner and also contributes to more fuel. I would consider adjusting mix out a turn more. mine ran like that before I adjusted to 3 1/2 turns out. whats your elevation? 5000?

 

I am pretty sure my elavation is 600

 

Try putting your stock needle back in. I had no luck with the DynoJet needle. Yeah, I know, $69 for a Dynojet kit, when you could have just bought a $2 mainjet. We've all been there.

 

Stock needle with the DJ 180 main jet?

 

Thats how mine ran when i was to rich.I had a 175 and clip on lowest groove.
I changed to a 170 and stock groove it now runs good.At least it did before the drop in temps.