600 rmk not holding the revs

[flygti32]

2012 600 rmk 144. 1700 miles now. 340 miles on clutch belt, just had the primary spring changed to a bright green epi. 150/340 at 1440 miles. I can get 8300 rpm but as i get into the deep in a field or cattail edge it just wont hold the rpm, it drags down to 7500rpm then once i come through it will start to pick back up. Why wont it hold the rpm? secondary spring sacked out? or top end starting to show the miles? primary spring to stiff?

 

[Aker]

Was your stock spring a black green? What primary weight are you running? 64? If it ran fine when you first installed the spring I would replace the secondary spring, and clean your primary again. Then clean the exhaust valves next if the problem still happens.

 

[flygti32]

yes stock spring was black green. 140/330. VES valves cleaned at 990 miles and again at 1440 miles.

 

[starfire72]

could be a broken exhaust valve spring or damaged exhaust bellow, .....have u for the heck of it tried a new belt. sometimes it something simple

 

[gopher-it!]

2012 600 rmk 155 , stock drive spring sacked out at 600 miles. 110/310. on a spring tester. 60 gram mds, 120/ 330 polaris black, black purple sec spring with a 58/44 helix. 82-8400 rpm.Back shifts very well. Oh slp pipe and par head@ 12.5-1

 

[flygti32]

could be a broken exhaust valve spring or damaged exhaust bellow, .....have u for the heck of it tried a new belt. sometimes it something simple

Belt on it has 500 miles, first belt it had lasted 1260miles. could be a bad belt, i am going to be changing the secondary spring to a 160/280 and put on a new belt, see what happens.

 

[Dazzler]

It would not reach the 8300 if there was a problem with the exhaust valve/spring or bellows... It sounds like it is not backshifting, I would go through the secondary, clean it, new spring etc.

 

[starfire72]

It would not reach the 8300 if there was a problem with the exhaust valve/spring or bellows... It sounds like it is not backshifting, I would go through the secondary, clean it, new spring etc.

wellll...i have had it happen before?? rpms very sparatic when valves dont work properly

 

[blackie205]

i would swap secondary spring and belt add derlin washers and gear down and swap track if i where u lol maybe swap out top end add par or bmp head and hold the fak on cause the pow is deeeep u will need every hp u can get bud

 

[flygti32]

So the new secondary spring went in today 160/280. 3 delrins washers as well. I scrubbed the belt in sunlight dish soap and a red scotchbrite pad, amazing what came off the belt. On the flat it will rip up to 8300 no problem and in the deep it held 7900 rpm quite well, it would bog to 7300 as of yesterday in the deep. I am going to drop down to 10-60's from 62's in the primary now and see what happens. If that doesnt help then maybe a 19/42 set up on the chain gear. Thanks for the input so far guys, its help me get a better understanding of this machine.

 

[gopher-it!]

We've had three of these 600's and never had to clutch that heavy. There is no way that clutch can even shift with those heavy springs. As in previous post I would look for a pin hole in one of your exhaust bellows, or a reason that they are not staying open under load. We've had your exact same problem and it was a ripped bellow. Also check your primary rollers and weight bushings. Pull exhaust valve hoses off and make sure they are all clear and not plugged off.

 

[flygti32]

well i put the 60's in yesterday, hits 8400 rpm in low snow and holds 8150 in the deep. Clutch seems to be working quite well with this setup now.

 

[iluv2fly]

Best thing I did was install the carls helix. It is a 62/38 and backshifts awesome and launches harder out of the hole than the stock helix. Excellent upgrade in my opinion.