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Discussion Starter · #1 ·
Heres my setup now, Crankshoptwinpipes,ported engine,Boyesen cages,Gutted airbox,Slp intakekit and flowrites,ss valves. 490 mainjets. Clutching-primary 140-340 slp spring, Epi 64 weights also have tried 62 and 66 epi weights. 64-44 teamhelix with black spring. have the team 720 helix and Red/black spring on order but looks like it never shows up. 24/41 gearing,1,5 Ripsaw. cc distance,belt deflection,offset all is good. New enginemounts. This sled makes power at 8400 rpm(8500 on the tach). But the sled can only rev to 8000 rpm on the tach(7800 rpm on the calibrated tach). I have tried different main jets and weights but nothing happens. do you guys have some tips. Thanks
 

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Discussion Starter · #3 ·
What is your compression, what is the timing at? Which ves springs, and you should be around 450-470 mains I would think.[/b]
I havent checked the compression,but the head is modified for lower compression. also new jugs. havent cheked the timing,what would be safe to set it? I tried both the green/yellow and the pink springs with no difference. Can i relly go so low on the mains? the plugs look light brown now. Thanks
 

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You should have around 140lbs or more of compression. If it doesn't respond to leaner jetting or the weights, possibly the compression is too low for the porting? I have seen this before.
 

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My guess is your PTO crank bearing might be starting to go away. We just chased this with a 02 800XC. Sled just wouldn't turn R's no matter how light we went with weights etc. Tore the motor down and lo and behold the PTO crank bearing was just about toast. Might want to take a look at that...

XCR5
 

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Discussion Starter · #7 ·
okey. Im going to check compression. i think i be fine by looking at plugcolor. No the bearings are fine,i just had the motor apart and checked the crank and bearings. I used to run AAEN twinpipes before the crankshops, the aaens didnt like the high compression so we lowered it. But maybe the cranks like higher compression. If you have more tips i would be happy. Thanks
 

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Did you try a different belt?

Are you sure your valves are opening?

Check port so not pluged. take ves assembly off, spit on hole, rotate clutch by hand, bubbles should blow spit away.

Also check the ves assembly. Take ves ass. off, push guliteen in, put wet finger over hole in cap, release guiliteen with other hand. should come 1/2 way out and stop.

Edit.

Also try some poo weights, maybe the epi's are wrong for the torque of the engine. dalton pro's are best, poo's will do.

edit #2

What year sled? , 03 ignitions sucked.
 

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Tune your sled using plug color first. piston wash can take miles to change, plug color changes within1/4- 1/2 mile.
 

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Discussion Starter · #11 ·
Did you try a different belt?

Are you sure your valves are opening?

Check port so not pluged. take ves assembly off, spit on hole, rotate clutch by hand, bubbles should blow spit away.

Also check the ves assembly. Take ves ass. off, push guliteen in, put wet finger over hole in cap, release guiliteen with other hand. should come 1/2 way out and stop.

Edit.

Also try some poo weights, maybe the epi's are wrong for the torque of the engine. dalton pro's are best, poo's will do.

edit #2

What year sled? , 03 ignitions sucked.[/b]
i tried several belts, but not new one going to try new one-dealer had no new home. Im not 100% sure the valves open properly. i put the ss in this season. last year i run the originals and the sled was really fast on top end. im going throu the valves tomorrow. i also have poo weights to try. its an 03 Pro x. With Perc so the cdi is a diffrent one. rode the sled today and it seems the belt slips a little.
 

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my piston wash changed after the first 1/2 mile across the lake. but i would expect it to take longer.

i just dont want to see another sled smoke a motor due to using plug color as a jetting tool, i have seen it happen too many times.

trying to help like the others here.
 

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my piston wash changed after the first 1/2 mile across the lake. but i would expect it to take longer.

i just dont want to see another sled smoke a motor due to using plug color as a jetting tool, i have seen it happen too many times.

trying to help like the others here.[/b]
Very good.

Its just some oils, and fuels, can change the amount of wash that is good for the engine.
Plus Its harder to see down in the jug for me, ( think its time for glasses )

Sorry if I came across the wrong way, wasn't ment to. But plugs will show signs of detonation, to hot a operating temp, before a piston does. I've found it to be more instantaneous. I use wash also, just seems it needs a few miles to get the full state of tune.

Both are very good tuning tools. :div20:
Now if we only had snow :banghead:
 

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Discussion Starter · #15 ·
i have checked the clutches today and they seem fine. But i going to change the helix to the 720 and the spring to Red/black but it looks to never show up. I put 2 seasons on the black secondaryspring so its time to replace. im checking the valves tomorrow. and trying to get a compressiongauge to check the compression. Also have the old Cdibox to try. i have some 470 mains to throw in but im little scared of burning it down. i let you know how it goes. Thanks everybody
 

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This sled makes power at 8400 rpm(8500 on the tach). But the sled can only rev to 8000 rpm on the tach(7800 rpm on the calibrated tach). I have tried different main jets and weights but nothing happens. do you guys have some tips. Thanks[/b]
FWIW
I have read over at snowest that guys had to get their CDI's reprogrammed to run at those rpms on the 800.
It was something to do with the cdi over rev protection kicking in over a certain rpm??
 

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okey. that seem not god. at exactly what Rpm that happens? Have you guys that run twinpipes over 8000 Rpm reprogram your cdi?[/b]

Check with some speed shops like HSP, SLP, Reichards or HTG.
They should be able to set you straight on this
 

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Discussion Starter · #19 ·
Oh i live in sweden far away from those companies-not god. I checked tha exhaustvalves today and they are fine. Also looked the wash. At the jug at the primaryside it was black with 4 small lightbrown spots on the outsides of the jug. The other jug was black with light brown halfmoon on the outsides at the exhaustside. What do you think of that? im using alittle oil in the tank also if that play a game in the wash? trying to look at my compression in the middle of week
 

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The timing curve begins to retard rapidly, which act as a rev limiter of sorts. I do not know what rpm on the 800 it starts to do that. I know the 97-00 700 twin, 8500 is where it does not want to rev past with twin pipes.
 
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