First run after rebuild/ cpr head jetting suggestions??
162.5 162.5 165 main
1 3/4 1 3/4 1 3/4 fuel screw (change to 1 7/8 to lose idle hang?)
e4 e4 e4 clip postion
47.5 47.5 47.5 pilot
stock needle jet
Cpr head mod
Slp triple pipes
Shooting for 0 degree sealevel jetting.
Mostly just the first brake-in run. On off on rinse and repeat... mototune type breakin run
0 to -5 F
540 ft elev.
Dropped mag cyl for a while, swapped center and mag plug picked up all cylinders.
Backfiring a bit and hanging at 3k on idle, blip would bring it down to 1900.
Back fire never quite went away but the motor seemed to be getting stronger as it ran in abit. About 20 minutes of running on a snow covered lake.
Not quite pulling the 8900 the pipes call for (8600ish) but it really needs to be clutched for higher altitude (3000-5000) and I'll never have it fully loaded at this altitude do to crappy trails at this elevation anyway. We'll deal with clutching AFTER we get it running right.
Comments, Suggestions.
No I haven't pulled the plugs yet it was dark and this was mostly just a breakin trip but something didn't seem quite right jetting wise.
Thanks guys
Erik
162.5 162.5 165 main
1 3/4 1 3/4 1 3/4 fuel screw (change to 1 7/8 to lose idle hang?)
e4 e4 e4 clip postion
47.5 47.5 47.5 pilot
stock needle jet
Cpr head mod
Slp triple pipes
Shooting for 0 degree sealevel jetting.
Mostly just the first brake-in run. On off on rinse and repeat... mototune type breakin run
0 to -5 F
540 ft elev.
Dropped mag cyl for a while, swapped center and mag plug picked up all cylinders.
Backfiring a bit and hanging at 3k on idle, blip would bring it down to 1900.
Back fire never quite went away but the motor seemed to be getting stronger as it ran in abit. About 20 minutes of running on a snow covered lake.
Not quite pulling the 8900 the pipes call for (8600ish) but it really needs to be clutched for higher altitude (3000-5000) and I'll never have it fully loaded at this altitude do to crappy trails at this elevation anyway. We'll deal with clutching AFTER we get it running right.
Comments, Suggestions.
No I haven't pulled the plugs yet it was dark and this was mostly just a breakin trip but something didn't seem quite right jetting wise.
Thanks guys
Erik
Last edited:
Why the 165 on the mag? That could cause your backfiring and needing to swap plugs.
I would run slp specs on all cylinders, deviate from there and your in trouble. The head mod is insurance and you don't need to modify jets to accomodate (someone correct me if I'm wrong).
I would run slp specs on all cylinders, deviate from there and your in trouble. The head mod is insurance and you don't need to modify jets to accomodate (someone correct me if I'm wrong).
Belt was sitting about 2-3 mm below secondary (adjusted now)
Black(?) primary,
8DN10s with what looks like steel rivets in the tip and middle
(swap to aluminum in the tip)???
red and black team secondary probably 58-44
2 inch lug 144 needs to work best from 3-5000 but see some shelled out trail duty in the 0-1k range
Black(?) primary,
8DN10s with what looks like steel rivets in the tip and middle
(swap to aluminum in the tip)???
red and black team secondary probably 58-44
2 inch lug 144 needs to work best from 3-5000 but see some shelled out trail duty in the 0-1k range