11/28/2018 6:02 PM
Edited Date/Time: 11/28/2018 6:03 PM
The orange power band works best.
I have an '02 RM 134 that I bought last year. I don't trust used bikes until I have personally redone at least the top end. I've found disconnected power valves, really worn rings, missing jets, frozen linkages, etc, etc,etc.
When I got mine it "needed nothing". It ran like crap- no power down low, then a violent hit. I found a loose spark plug, a torn air filter, the powervalve 2 turns tight, way too rich jetting, and... that's all I remember. The linkage was almost rusted solid and there was NO lube in the steering head. The chain was new, the sprockets worn. I fixed all that and rode it for 5 hours before I couldn't stand not knowing and did the top end.
Your bike does have an adjustable power valve and the thing to do is remove the two bolts and pull it out. Make sure it's set to "zero" and then start with it about 1/3 turn up from there. I'll get pictures if you don't know what I'm talking about. The adjustable valve is lots of fun and will definitely change the hit, but it should still run clean at all RPM's.
Also, don't guess at the jetting. Find Pro Circuit's jetting chart, look at the OEM specs on RockyMountain ATV, and go from there. If your jetting deviates significantly from those, something is most definitely wrong.
2019 KTM 150 SX
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