I am getting frustrated. RPM help.

[95RXL]

08 D7 155
During my last trip out west I lost top end RPM runs like 7600 now.
Went through the clutches. No binding or problems in either. I put new springs in both clutches.
Went through exhaust valves. They are clean and bellows and spring are good. Solenoid working.
New fuel filter, new belt with deflection set right.
No kinks in fuel line. Compression is approx 115-120 per my tester. I am at a loss don't know what else to check. Any help would be appreciated. I even ran the high elevation weights at 1500' and it barely helps. Get like 7800 RPM's.

 

[winter4ever]

Im not sure about the 700s but I know my 800 seams a little rich on top. Have you looked at your wash and plugs? Not a lot you can do about it if that is the case unless you want to buy a programmer for it. Has it always been like this or did it used to run good? I run on the non ethenol setting with mine even with the e 10 fuel. That actually seamed to help a little on mine. for a while mine would only pull about 7900. I put on a new carlisle belt and its right at 8200 now.

 

[95RXL]

It ran perfect until the last two days of my trip. 8100-8200 RPMs. It has a turbo so I have a fuel controller and afr gauge. Afr running right around 12 at WOT. I didn't change anything before it started doing it. There has to be something going bad in the electronics?, Reeds?, Could the TPS cause this if it's gone bad?

 

[600rmk]

not sure if you mentioned plug gap. .020 is important. any idle problems. check tb boots and reeds. cracked boots are very common.

 

[95RXL]

Idles at around 1600. It's got the billet boots but I might just tear into the intake tomorrow to inspect everything and look at the reeds. Plug gap should be fine. Same plugs it had when running good. It acts like it's just shifting too fast and dragging the motor down but like I said the clutches have been gone through with new springs installed too. I hate to just throw stiffer springs in when it worked perfect before. It there any way to know for sure that the exhaust valves are opening all the way? I plugged the breathing hose for a couple runs and it didn't make any difference.

 

[francois]

yeah reed valve could be a good place to start. I agree with you why changing springs that were working couple days ago? DOesn't make any sense. I know you said the afr was ok but r u sure the fuel filter is not plugged?

 

[95RXL]

Fuel filter is 2 weeks old but can swap it out with the one I replaced to rule that out cause it ran ran fine with the old one. I appreciate the help so far. We will get this thing figured out.

 

[600rmk]

plug gap will get too wide with time and miles. what about motor mounts. you mention it sounds like its pulling down. exhaust springs, any cracks in the exhaust, bad chaincase bearing.

 

[600rmk]

tps problem would show up at idle as well.

 

[winter4ever]

It could be a busted motor mount. Or that little torque stopper dealy.

 

[95RXL]

I may have finally found it! Took the intake apart and everything is an oily mess. A few of the reed petal tips are fraying and none of the petal tips are touching the reed cage. Am trying to find some reeds today but should be able to get some in the next couple days for sure and will let you guys know if it helped.
The motor mounts all look good as does the torque stop.
BTW anything you drop under the motor (nuts,bolt, etc....) is gone forever!

 

[600rmk]

that definately sounds like it could be the problem. turbos can be hard on reeds. for higher boost; some guys have doubled up the reeds.Don`t really know how well that works. Had a friend who rolled his 900 and it wouldn`t spark after. turned out a bolt from the belly pan, fell into the drain hole underneath the stator and somehow got in and tore up the stator itself. crazy!!!

 

[DragonSlayer1]

Tip

I would pull the topend off and check the pistons.

 

[deepdiver]

gap at .027

Reed tips broken will be a pain at low RPMs...bad enough like a broken reed petal will cause a big bogging issue at low RPMs but at WOT the reeds are open anyway..not your problem.

You didnt mention if you checked the bushings on the primary weights.

 

[95RXL]

I would pull the topend off and check the pistons.

Did the top end a few days back. Old pistons were out of spec but new pistons didn't help my rpm's.

 

[95RXL]

gap at .027

Reed tips broken will be a pain at low RPMs...bad enough like a broken reed petal will cause a big bogging issue at low RPMs but at WOT the reeds are open anyway..not your problem.

You didnt mention if you checked the bushings on the primary weights.

Plug gaps are the same as they were when it ran perfect. .020 as recommended by my turbo builder.

Have had three different set of weights in it when trying lighter weights to see if that helps. Bushings aren't the problem. Believe me.....the clutches have been gone through. I have 2 primary's and 2 secondary's and it makes no difference even with different parts in different clutches. The reeds need to be replaced anyway. The old ones are shot. I was able to get some today so will put them in tonight.

Anyone know where to get replacement petals for the stock polaris reeds. Looks easy to change them out but you can only buy the whole cage assembly from polaris.

 

[snoboy]

Didn't read all posts so... If you are running the factory helix you have a 42 finish angle and a black (huge POS IMHO 155-222) spring. That combo drives like a school bus on the bottom and is an rpm gulper on the hill. If nothing else try a new spring, red/black 140/240 (if you get a new 40 ramped helix) or red-pink 140/260 if you keep the factory helix. IMHO you should get a new 64-40 helix with a red-black spring. It'll bring that sled to life.

 

[95RXL]

The reeds helped a lot. I can get 8100 then it pulls down to 7900 as it shifts out. Way better. Might just increase the finish rate of my secondary spring 20#'s to get the last bit of rpm.

 

[600rmk]

especially if your running the straight 48 or 50. 180-260, or 180-280. glad your going in the right direction. whats your hi psi number, i am down to 50,

mine is also a 08 700 boondocker.

 

[600rmk]

Ther are some turbo specific reed petals available, but form what ive read they are still lacking.

500miles a set max for me. gets expensive.