Top end loss, Low RPM's, F7 smoked me

[paddocm]

Hey Guys. Having a little problem with my 03 RX. Seems like this year I've lost a bit of top end. Last year I saw 190km's on the speedo, this year the max is 176km's. Only seeing 9400 rpms. It hits 9400 right away but won't increase at all after that. I just installed a new belt and it's sitting nicely in the secondary now. What should I do?

On a side note, I raced a 03 F7 from a roll on. He pulled about 3 lengths on me in mid range. I was slowly gaining on him on the top end. Then he blew a belt Popped a hole in his belly pan. Those F7's are rockets. I need to get mine running perfect to take him.

 

[JDMCRX]

Yeah the 03 are rockets

What clutching u have done? and did u check ur air box for any little friends homes in there

 

[LABRADOR WARRIOR]

rpm's

I had the same problem with my 04 RX Warrior this year!!!!190's last year and this year 170ish Anyway ..I used this site to cure the problem the guys here are#1 My problem was in the clutching..Why the big change from last year ??I don't know why???But after listening to people like Turk and Lazy Bastard I installed a set of heavy hitters with a o-s-o primary spring and a silver sec spring set @ 6-2 and with 5/16 washers When I pin the throttle now ..the rpms jump to 10400 and stay there all the way through top end...took a little tweeking but man can this thing pull!!!top end now I'm hitting 195-198 on dream meter on icey road..It gets there alot faster also
I know my sled is a little different setup but,these few changes made a big difference

LW

 

[change_up]

The first thing you could do is check and make sure all the airbox boots are seated on the carbs properly. After tumbling dads 04 warrior last year i had the same problem, thought I damaged a few parts, beleive it or not, the difference between 1000 rpm and 20km/hour was that ONE of the carb boots was not on correctly. May not be your problem but for the time it takes you might aswell check that.

 

[grader]

something aint right. 9400rpm is no ware near max power on these motors. it has to turn 10200-10500. check center to center and offset, clean ignition coils, remove rubber and clean with brake cleaner to remove carbon. check airbox fit and clean foam. if these all check out and it still wont pull rpm, let us know.

 

[TonyVT]

Dont forget the belt..!!! This is huge.

The fact that yours blew makes me think it was well worn. Your gear ratios as well as shift points will all be out of whack witha worn belt.

I like Yamaha stock belts myself...

 

[culvert]

Tony the F7 blew the belt. not the yammy. if you havent cleaned carbs or clutches since last season, that is where I'd be looking

 

[paddocm]

I had the sled completed cleaned and tuned at the beginning of the season. I'm starting to think that where the problem is. Not sure I trust the dealer here. Not a lot of performance 4-strokes around. The mechanic couldn't provide me with any tips to improve the performance of the sled.

The sled is completly stock with the execption of the 1.25" track. 7200kms. Just replaced the original belt. Looks like I'll have to do a bit of clutching. What's the first thing I should change? Spring in the primary?

 

[grader]

change the primary spring to a yamaha orange-silver-orange.

 

[RX1-er-2005]

Make sure your only burning REGULAR gas 87 octane max...I was loosing 200 to 300 rpm's using premium.

I didn't beleive this t'ill I tried it!