860 BB problem

[Summit97]

I have a 860 RK tech BB on my 09 Summit. I was riding in Rabbit Ears this past week. I could only get 7400-7600 RPM out of it. I changed the clickers to 6 and it was running 7600-7800 RPM for one day after that it went back to 7400-7600 RPM. I'm running 17gram weight in my rollers. Just replaced about everything in the primary and secondary. I'm only getting like 50MPH track speed (gauge might be wrong) I'm lost on what to do. Any help would be great.

Summit97

 

[Summit97]

No one????

 

[swrev]

not much info to go from, but I would guess powervalve problem.

 

[Wyorever]

How do plugs look? Are your power valves converted to gas pressure? Have you tried calling Kelsey?

 

[duncan76]

From what I've always heard it must be bad gas.?

 

[winter brew]

Did it ever pull proper RPM at this altitude? If it did, have you changed anything on the sled? Different intake, belt, track, gearing, fuel....anything?

 

[Summit97]

It did after I changed the clickers. The next day I didn't change anything and all I could get is 7400-7600. I wanted to use up some of my son's AV gas so I was running it all day. Before the trip I put in new springs, buttons, And rollers in the clutches. If its the power valves why would they not work one day then work the next day, and not work the next day? I cleaned them before the trip. Thanks

 

[winter brew]

Too much octane can cause RPM drop, is this the fuel you typically run at high altitude? If not, try pump premium if that is the recommended fuel.

 

[byeatts]

Too much octane can cause RPM drop, is this the fuel you typically run at high altitude? If not, try pump premium if that is the recommended fuel.

Yep. everyone thinks Race fuel is better, It will drop Hp considerably .

 

[Summit97]

Kelsey said to run 1-2 gals per tank. That's what I was running. Till the last day of my trip I tried the AV gas to see if it was the fuel. The problem started on the last trip last year out in the Black hills. So that's why I rebuilt my clutches. I did clean the power valves before the trip along with the carbs. Is there a test I could do to see if the valves are working right? Just running out of ideas.

 

[FEZ]

check compression

 

[winter brew]

Kelsey said to run 1-2 gals per tank. That's what I was running. Till the last day of my trip I tried the AV gas to see if it was the fuel. The problem started on the last trip last year out in the Black hills. So that's why I rebuilt my clutches. I did clean the power valves before the trip along with the carbs. Is there a test I could do to see if the valves are working right? Just running out of ideas.

Yes, pull the plastic cover off the valves. Take off the side panel and clutch cover so you can see the valves. When you start the engine, they should both suck all the way in. Under moderate throttle they should both return to the middle. Under heavy throttle (grab the brake and briefly hit the throttle) they should extend all the way out.
Also check the DPM solenoid for function with a 9V battery. Its the gold colored solenoid above the carbs. Unplug it and use a 9V battery and a couple pieces of wire, it should click. If it doesn't click it may be sticking and causing it to run rich. This was common and Doo had a bulletin about this. To fix, take it apart and clean with WD-40. watch for the 2 o-rings if you take it apart (1 small screw to disassemble).

 

[Summit97]

I took the exhaust covers off and started it up. They didn't go in. Now what could it be?

 

[revx827]

I usually start by making sure that valves move in and out freely by hand.
Then check that lines are all hooked. Then move on to checking the solenoids.

 

[Summit97]

I looked at the lines and they are hooked up. I guess I'll have to check the solenoid. Winterbrew said to check it will a battery and wires. Does is matter what one is power and what one is neg? Maybe I will just take it out and clean it.

 

[bmiller1985]

I looked at the lines and they are hooked up. I guess I'll have to check the solenoid. Winterbrew said to check it will a battery and wires. Does is matter what one is power and what one is neg? Maybe I will just take it out and clean it.

when was the 860 kit installed? how many miles since you installed it? if you ran it before and it ran better what fuel were you running? you mentioned going through the primary, did you change anything in there before riding it? where do you usually ride it and what altitude? and last, any fueling differences (jetting, fuel controller, etc)?

 

[bmiller1985]

I looked at the lines and they are hooked up. I guess I'll have to check the solenoid. Winterbrew said to check it will a battery and wires. Does is matter what one is power and what one is neg? Maybe I will just take it out and clean it.

one more question, when you popped the cover off and said the valves didn't move on start up, did you check to see if they moved freely in and out by hand when the sled wasn't running?

 

[Summit97]

The valves move in and out easy when the motor isn't running. I have between 800-900 miles on it. I run the same fuel mixture from day one. 91 premium with 1-2 gals of AV gas per tank ( Kelsey recommends it) . I have rode the same set up from 2000'(here in Mn) to 10,000' in Cooke city Mt. I put the same spring in the primary that Kelsey told me to. Both when I put the BB on and when I rebuilt the clutch. I have not changed the jetting or anything from day one. It started to act up last year in the Black hills. That's why I rebuilt the clutches. Went out to the Rabbit ears this year and the same thing is going on. That's why I can't figure out what is going on, I haven't changed anything.