03 yz85

[yz450thumper]

What would be the best pipe for bottom end on this bike? My son doesn't ride hard enought to keep it rapped out so i need to get it to run off the bottom better any suggestions?

 

[03YZ85Rider]

I don't think any aftermarket pipe will noticably increase low-end power on the YZ85. I have a Pro Circuit platinum and it actually has less low-end power now then it did with the stock pipe, and yes it is jetted properly. I would spend my money on Eric Gorr's low to midrange porting if I were you, it's half the price of a new pipe and probably twice as effective. Keep an eye on the silencer packing, mine likes new stuff every 2 or 3 weeks or it runs terrible at low RPMs. You might want to experiment with larger rear sprockets, maybe a tooth or two bigger. With the stock 14/47 gearing you really have to slip the clutch or shift like a madman to keep the bike in the power. You could try a shorty silencer too but I don't know if there are any real power gains to be had there either. Hopefully someone that has tried one will chime in. I hope this helps some.

 

[yzJoKeR]

The gearing change was the best thing I did when Julia was riding a 80.On her 96 yz 80 I ran a 13/52 which I think is around 4:1.

 

[trout]

My wife rides an 03 85. we test rode whyzee's sons 85 with a flywheel weight, it didnt have more bottom but my wife said it felt less pipey. He might like that better. Im gonna try some different sprocket sizes once they wear out and see if that helps. My wife just putts around on it in trails so I think a little more bottom would help her.

 

[wade450f]

My son went from a xr100 to the 03 yz85.
we trail ride and cross country race

The transition was much better with
a smaller countershaft sprocket.

First gear was very slow but the
bike was always 'on the pipe'
and it didn 'load up' and foul plugs
(I had the lean out the jetting also)

He eventually went back to the stock countershaft
sprocket after getting comfortable with
the powerband and bike in general.

 

[yz450thumper]

This bike has been a nightmare to jet and still it aint right i'm gonna get a leaner needle and see if that helps if not I got a 03 yz 85 for sale LOL.

 

[wade450f]

Make sure you check the float.
I did a search here and found some jetting help
last april when the bike was new.

 

[yz450thumper]

Make sure you check the float.
I did a search here and found some jetting help
last april when the bike was new.

I have checked everything the from the floats to the reeds and even did a top end on it and still runs like crap. :eek:

What kinda compression do you guys have on your 85's?

 

[whyzee]

Not sure where you are located, i.e. elevation, temps etc... but, get the jetting right before changing the pipe or reeds. no sense chasing a problem without a baseline to start.

Eric, you look like you've been on a shopping spree in the arcade. LOL