Big Bores
- Thread starter lords88
- Start date
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Hi there. I had a UB944 for three years and loved it. I now have a UB980 that is based off the SRX bottom end. I run a Polaris clutch with 56gram weights with stock secondary and a Team secondary. I had Richard Swenson from BC build my pipes and Lowell Horning perform his magic with the porting. I ran the Mach z 38 rack of carbs with power jets from Jack Harris autobody. It was very reliable spinning at 9000rpm all day and made excellent power. Had to run a mesh hood for overall heat dissipation from the motor and run a extreme 156x2.5x16 track under it. Awesome engine. I have all sorts of set ups I tried if you need help. Shad
Well right now I am running a polaris primary with 56 gram weight, a Team secondary 58-38-36 helix and redblk spring, stock carbs, pipes from Richard Swenson, stock carbs and a 159" track. I spent all winter working on getting better backshift, could only hold 8,000 rpm on a pull. Now I have a stock secondary and a shockwave helix but didn't get to test it this spring.
I've got a 950 Price in a mod MM chassis and recently built a 944 UBR/Fastrax engine for another project. I also run a SLP 800 kit. Sounds like you are clutched about right. What primary spring you runnin? You should be getting much closer to 9000 rpm with what you have there. How long since the clutches were rebushed? Are you using a fresh 8DN belt? I'll see if I can dig up my clutch setup on the 950. I am running P-85/Team setup on mine. If you want another Yami big bore to play with I'd sell ya any one of mine. I have moved back over to the four strokes again and don't need all of the sleds I have now.
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Lords,
Shoot me an e-mail address and I'll send you a spreadsheet with numerous set-ups for the UB944. Great motor.
If anyone else needs the spreadsheet let me know.
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Shoot me an e-mail address and I'll send you a spreadsheet with numerous set-ups for the UB944. Great motor.
If anyone else needs the spreadsheet let me know.
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Yamamauler I have your spreadsheet already, thanks again! I just started this thread to see what everyone else is running and how many of these sleds are still running around. I think for next fall, I am going to upgrade the suspension, maybe bigger carbs 38-40s, powerjets, new high comp. heads, kick A filters, some new lightwieght trailing arms (kinda bent one), and the stock secondary with shockwave helix. That should pretty much complete my sled.
My clutches are practically brand new (about 300miles on them) and still clean as a whistle. Still running the 8DN belt and my spring is the Polaris almond. I can pull 9000 on flat ground but couldn't get it to pull the R's on the hills. Might be gearing too need to check that out this summer and make sure it's correct.
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Lords looks like you got lots of help. I see MrFusion posted above, he's a smart cookie. PM him he's tryed many carb and intake setups, and can likely save you some trial and error. Pretty sure he built three or four Mmax's with that motor. I seen most of them in action, very impressive sleds..
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I gave you my specs earlier. Let me know if you need them again. What size drivers do you have? I have 9 tooth and I'm geard 19/42. Ran 19/40 and worked just fine too.
I run 19/40 gearing with 7 tooth 3" pitch drivers. I run a Purple Cutler primary spring on the 950. I'll get you the part number for it tomorrow. Team TSS98 Secondary spring is the red/black Helix is a 54/42right now but I have tried 58/44 and others in that neighborhood. They all work well. I use a 52/36 on the 800 and that is only helix to use on that one. I cant remember if primary has 58 or 56 gram cutler weights in it now but I only run 8700 RPM with the Bender pipes. Sometimes it hits 9 or more when I am using the NOS
Well I went out today and checked the gearing on my sled and it was 19/40. Is that too high of gearing with 9 tooth drivers or should it pull that? I believe that mathematically puts my track speed at alittle over 90mph.
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19/42 will give you a better gear ratio. I highly doubt you will ever see 90 MPH track speed.
try an arctic cat sec spring like the yellow or red. I had the BB 835 from bender fully done case ported 38 carbs from the Z and that was the only spring that worked for the back shift, I used a 56/47 on a roller secondary and 54 gram weights in front....02
I think he means top speed...my track speed was 58-63 mph depending on the snow and I was geared 2.2-1
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Tripleswillnever die... who built that engine/sled?
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Should have bought mine. I threw in the rest of the sled too!
I have one in nw colorado. $1500 for motor carbs and pipes or $2000 for whole sled. 2000 mm with mpi tunnel boss seat and more. old sled, kinda beat up but runs good.
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