2015 pro RMK shy on rpm

[Klimbing Kitty]

sled will hold around 7800 rpm. spikes to 8000 and the falls off. dropped 2 grams in clutch and did not make a difference. On flat hard packed it may hold 8000 to 8050. When sled was new it would hold 8350 no problem. Any ideas? compression? clogged fuel filter starving for fuel under load?

 

[Reg2view]

Sounds like you know its time for a fuel filter, anyways. Then start with the belt if haven't put a new one on already - even tho they look good, at 500 miles, it's not unusual to start losing RPM, put a new (washed and broke in, of course) one on, and wham-o, RPMs back. Then sacked springs, worn buttons, binding. Can be other issues, fuel pump, plug wires, caps, injectors, VES, etc., next, but it's like chasing a ghost, especially if you don't nail down clutching completely, first.

 

[Pro116]

How many miles on your beldt.Have you checked your deflection?

 

[Klimbing Kitty]

How many miles on your beldt.Have you checked your deflection?

Belt has maybe 100 miles and was broke in properly. roughly 2000 miles on sled

 

[Pro116]

I would try cleaning the valves.

 

[eyefish123]

I had the exact same issue on my 2015 660 Pro. Went through clutch, new fuel filter, exhaust valves, plugs, etc. Am not sure if I got problem fixed because it happened at end of year and snow got heavy so am hoping some loss of RPM was due to the heavier snow. Hope this thread keeps going and you get your problem figured out. Good Luck!!!

 

[Klimbing Kitty]

I would try cleaning the valves.

Have cleaned the valves

 

[The Bob]

Have you done a compression check? Rebuilt top end? 2000 miles on stock pistons would be a worry of mine.

 

[FlatLander909]

TPS is off. Had this problem on my 15 800 pro.

 

[FTXMOTORSPORTS]

We've seen a lot of CFI engines with the exhaust valve pressure port through the cylinder plugged with carbon also-another quick easy one to verify that will kill rpm!

 

[trench]

A lot of good suggestions here , but just to add seems like you might need a top end .
do a leak down test will tell the whole story .