Ok i have a 99 polaris 400 sport when i got it the stock motor was fried! So i took a 90 Polaris 400 double and cramed it in it. It euns great idles great problem im havin is when i put it in forword it jumps out of the hole but once i hit like 15 mph it acts stupid like its a carb issue but its nothin with motor because when i put it in Reverse it comes alive!!! I mean stupid fast in reverse almost like forward abd reverse are switched the guy i got it from had his hands in the trans any ideas?

 

As far as a sled motor,can't help you much on that,but sounds like it's limiting in forward by your description. Pull the reverse limiter black wire located under the front panel and see if solves the problem.

 

Sled motor is fine it in the trans i believe because in reverse it flys as if i was in foward but i didnt see any wires comin from the trans

 

The limiter is under the front panel. Just pull the black wire from item#30 and see if it helps. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

Ill check that out now does that go staight to the trans or to the motor harness?

 

It goes to the electrical harness not the gear case. If a limiter starts failing it can default in forward range also. May or may not be the problem,but wont hurt to disable this module that fails quite often and see if it helps.

 

I used the sled harness deleted the atv harness could the reverse gear and foRward Gear be backwards? Cuz some idiot said he rebuilt it?

 

Kinda hard to swap these gears around because the internal silent chain has to ride on the forward gear.Reverse is actually gear to gear and the forward range is driven by the silent chain allowing faster speeds. Still think you have some sort of limiting problem,but I've been wrong before. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

Well in reverse it dont spit and sputter but in forward it does at like 15 to 20mph idk

 

I got it thank u old polaris tech!