[keithstef]

My brothers F5(Stock, excpet for 144 - 1.075 studs) seems to pull good off the line, but at ~55 mph(GPS verified), the sled stop accerlating. :huh:
I stayed WOT for awhile(~10 seconds) before I notice I was only up to 58mph!!!!
Tach stays at ~ 8000-8100 rpms during this time.(Can't remember exact #)
Any sugestions what to look at?

Thanks
Keithstef

 

[Wicked King]

:huh:
If the sled seems to be running okay otherwise...who knows? I'd check your carb linkage first. Maybe the slides in the carbs aren't opening all the way? 10 seconds of WFO should bring a hell of a lot more than 58mph! odd...very odd... <_<

 

[jbscapitol]

sounds like power valves aren't opening. Which will give you good bottom and no top with 200-400 less rpm at wot.

 

[Evil Twin]

I don't know the top RPM or speed of the F5 but would think 81 to 85 hun would be close. My ZR6 pulled 8500 to 9000 though. I needed to pull her down with clutching to get my ETA down.
I think you should check your clutching as you have no trouble with RPM just speed.
Something is not hooking up properly between the motor and the track. The clutches are the first place to check.
What shape is the belt in??
Evil

 

[Bontz]

Not to sound like an idiot, and stating the obvious ... but you're sure you're running on both cylinders, right?

 

[keithstef]

Wicked King: Haven't check the carb linkage to see if they are opening up all the way.
jbscapitol: We did check the power valve adjustment when new and they did function. We have only 150miles on the beast at this point.
Evil Twin:Belt sits level in the driven clutch. I'll wash down the drive and driven clutch. Maybe some oil residue??
LabonteF7:Will check the plugs tonight to see if both are light brown. Since it pulls so hard off the line to this speed, we did pass over this check.

Thanks for the help!!!
We will get a chance to look over the beast tonight. Possibly pull apart the clutches.
Will update with news..
Question:
Is it safe to run the motor on the stand without the belt to check if the drive clutch shifts out??

Thanks
Keithstef

 

[Evil Twin]

DANGER, DANGER, DANGER.
Do not run her without a belt and clutches.....Repeat.... DO NOT run her without a belt and clutches.
If anything goes amuck she coulds easily over rev and blow up real good.
Evil

 

[ZRT Guy]

I don't know the cause of your problem but mine will rev to 8300-8400 rpm's, and ten seconds ofg WFGO throttle will produce a heck of a lot more that 58 mph.

 

[BRAD81]

HOW TIGHT IS THE TRACK?

 

[cmscat50]

Check EVERYTHING!!!

 

[gatsledder61]

Brad, good point on the track. Mine was WAY too tight from the dealer. I thought that once I added the weight of the studs, the track would loosen, but no luck. I wish I could verify the top spped of this beast, but we got no friggn' snow!

 

[SnoPro28x]

hey, i had that problem to, i brought my sled to the dealer, one apv was sticking, got the sled back and got 105 out of it

 

[keithstef]

Track tension is 1-1/2" with 20lbs. Please let us know what you recommend.
Thanks for the info about no belt. That would not make my day.

Sounds like we should check the APV's.
We did check the APV valve measurement when new and found that they needed to be adjusted. We set the cable adjustment to ~36.5mm(36.1mm to 38.1mm is the range the book states)

If that is not it, time for the dealer....

 

[jbscapitol]

your apv's are stuck closed. Take the cover off the servo and run the sled on a stand you will see they are either stuck the cables are not returning or they are not working at all. With pre mix and the fat jetting these things come with they are probably gummed up. My 2001 and 2002 zr500's gummed up at 100 miles and I had to make lots of carb adjustments (jetting, air screw ,fuel screw) to get the valves not to stick and the sleds to run crisp. These things are even jetted fatter than the zr's were.

 

[keithstef]

We did not get a chance to tear into the 5 cat last night.
This sled has ~150 mile on it at this point and the oil consumptions had been high.
We did put ~10 mile on at home with 2 mile running on the grass and the rest with ~2-4 inches of snow.
After that we notice oil was going down, so we filled it back up. Also, we filled the gas up at this time with ~ 5-6 gallons of straight gas.

Anyway, went to Old Forge during the Shoot Out weekend and put a quick 120 miles on. We put in less than 10 gallons of gas. ( Can't remember, but I think it was 9) But I dumped 1.5 qts of oil in. My F7 same mile took ~3/4 qt with same amount of fuel.

Will update after we inspect..

 

[f-5snopro]

is the belt slipping? i think mine is along with earls...........

 

[keithstef]

Finally worked on the F5.

I took the power valve servo cover off to check the valves and what did I find: One of the cables came out. :blink:

I guess that it must have stuck open slightly and the servor return to the closed position, the cable end came out.

For now we rotated the cable end 180 degree, this puts a small amount of tension and doesn't seem to slip out so easy.

After we adjust the oil pump down, maybe we will not have problems with the valves.

 

[VFRcanada]

I had the same problem with my 2002 ZR600CC. The one power valve cable closest to the rear kept coming out of the slot on the pulley of the servo motor. I slipped a washer between the Controller Pulley (item #2) and the servo motor (item #1). That way there was no room for the cable to come off.

 

[CatMan2]

I had the same problem with My F5 first time out. Come to find out the exaust temp. sensor had come out. If Yours is still in maybe it has a short or isn't hooked up somewhere. Check it out!!

 

[lspr]

i have same problem with my f5 put 200 miles on it first 110 ran 8500 rpm then 110-150 miles it would only pull 8100-8200 then from 150-215 miles it would only pull 7800-7900 rpm i havn't had a chance with x-mas to look at any thing yet sounds like same problem. keep me posted if you find the fix
i had noticed that my exaust temp sensor had come out put it back in then it stared having problem

ps love the sled