• Don't miss out on all the fun! Register on our forums to post and have added features! Membership levels include a FREE membership tier.

Carls 910

S
Oct 22, 2008
10
0
1
48
Just got a carls 910 with bored carbs and all electrical. Is this motor supposed to run twin pipes?, will it run a single? Should I pull the oil pump and presto mix? I had a psi 990 that's had big air carbs and twin pipes, but also a couple of good buddies who real,y knew and had the motors, I moved away so I'm on my own now. Any info is appreciated!
 

Merlin

Well-known member
Lifetime Membership
Oct 7, 2004
1,183
300
83
Medicine Hat, AB
Forum members sled_guy & BILTIT both run these and would know for sure.

My recollection of my friend's 2 910 engines was that SLP twins were needed along with boring of the factory rack carbs(don't remember what size?). Oil injection was removed and fuel was premixed. Those engines seemed to need substantially more air than an 800 so plan on intake mods. as well.



Just got a carls 910 with bored carbs and all electrical. Is this motor supposed to run twin pipes?, will it run a single? Should I pull the oil pump and presto mix? I had a psi 990 that's had big air carbs and twin pipes, but also a couple of good buddies who real,y knew and had the motors, I moved away so I'm on my own now. Any info is appreciated!
 
S
Oct 22, 2008
10
0
1
48
Carl's 910

It does come with the bored out carbs. I'm just looking for a set of pipes, I found some cpi twins. I have called Carl's cycle just haven't talked to anyone yet.
 

BILTIT

Well-known member
Premium Member
Apr 9, 2011
1,682
482
83
45
Lloydminster, SK
Yes they need twin pipes, SLP's are the recommended.

Additional air is key, these things need to breath deeply!

What sled are you putting it in?

I have some spare slp twins for an rmk chassis.

I still run oil injection.
 
Last edited:

sled_guy

Well-known member
Premium Member
Jul 5, 2001
3,566
843
113
Riverton, Utah
Biltit is right. Never ran anything but SLP twins. I know some people tried the SLP single, but never got it to work. The cylinders have a different mounting flange setup so you need the flanges from Carl's for them.

I run the oil pump and run a little premix oil in the gas as well.

These are NOT pump gas motors. You'll need to run at least a couple of gallons of Av or race gas depending on which head you have and what altitude you run at.

sled_guy
 

BILTIT

Well-known member
Premium Member
Apr 9, 2011
1,682
482
83
45
Lloydminster, SK
Good point about the avgas/racegas, forgot about that.

I run 30% avgas/premium at 2200ft, i do not recall which compression head i have but it is not the highest.
 
S
Oct 22, 2008
10
0
1
48
Carl's 910

It has 160psi per cylinder, is it worth running individual air filters on the back of the carbs? I had a 990 psi with big air carbs that was set up that way! I do plan on mixing race fuel with clear fuel( non ethinol). I ended up getting a set of cpi twins for it, talked to a guy at Carl's who said they would be fine. I'm just wondering about clutching I'm at the 6000 to 8000 range of elevation and just need some base lines to start at!
 

BILTIT

Well-known member
Premium Member
Apr 9, 2011
1,682
482
83
45
Lloydminster, SK
I think stock airbox is best, thats what i used.

I run at 2200 so i dont think my setup will be of much help.

Sent from my SM-G925W8 using Tapatalk
 

BILTIT

Well-known member
Premium Member
Apr 9, 2011
1,682
482
83
45
Lloydminster, SK
I had mine in an 03 vertical edge for one or two mountain trips but i cannot recall the clutching setup. I also had an atacc on it so i didnt need to adjust jetting from what i had at 2200ft.

Sent from my SM-G925W8 using Tapatalk
 

BILTIT

Well-known member
Premium Member
Apr 9, 2011
1,682
482
83
45
Lloydminster, SK
What i do remember is it didnt swing much more weight than my 800 did, but i also had a lower initial primary spring in the 910. It really pulls hard though, not a hp king but sure is a torque monster.

Sent from my SM-G925W8 using Tapatalk
 

05rmksteve

Well-known member
Staff member
Lifetime Membership
Premium Member
Sep 5, 2008
2,477
1,618
113
Brainerd, MN
Run the stock air box gutted and slps air horn and flow rights 1 large 1 in place of speedo and 2 smaller ones. Blue pink primary spring with 10-62 weights if I remember right I would have to look back in my notes to see what I'm running in my secondary. I'm also running a atacc. I have 2 Carl's 910s 1 is in my 05 rmk with a 155 2.4 track and the other is a spare.
 

BILTIT

Well-known member
Premium Member
Apr 9, 2011
1,682
482
83
45
Lloydminster, SK
Sounds pretty close to what i had in mine i think, except i use the black/pink primary spring (120/340 vs blue/pink 140/340).

I had a TIED for secondary so wouldn't be applicable.
 
S
Oct 22, 2008
10
0
1
48
Thanks for all the info! I have a set of cpi twins I found, and I was also wondering, which I'm pretty sure but those 910's run watercraft jugs? Cause obviously the exhaust flange bolt pattern is different. And was wondering if my stock ecm and harness will work, the motor came with all that, just wanted to make it easy and not do a whole harness!
 

05rmksteve

Well-known member
Staff member
Lifetime Membership
Premium Member
Sep 5, 2008
2,477
1,618
113
Brainerd, MN
The jugs are custom from what I've heard/read crank shop made the jugs and Carl's did his porting on them correct me if I'm wrong. Yes stock 800 ecm and harness will work.
 
S
Oct 22, 2008
10
0
1
48
Cool, thanks! Just noticed the different bolt pattern, which isn't a problem, I can fab. On the exhaust that is. And all the clutch and jet info is much appreciated.
 

sled_guy

Well-known member
Premium Member
Jul 5, 2001
3,566
843
113
Riverton, Utah
Crankshop rough cast jugs then Carl's machines and ported them to their specs.

If you can get Carl's to reprogram your CDI you will bet a bit more RPM out of it before it hits the rev limiter as well as moves the temp threshold up a little. Neither are necessary, just nice to have.

sled_guy
 
Premium Features