Right now, I have my valve covers/rocker covers off of my P650 motor, and my rear cam is removed b/c I'm in the middle of installing stock V-force cams. I'm hoping to finish this installation in the next few days (working on it a little bit each day after work).

To anyone who is thinking of doing a cam upgrade on your big Prairie, please be aware that I had a problem unscrewing the 2 camshaft sprocket bolts on the rear cam after I removed the cam from the head. I ended up rounding off the heads on both of these bolts (these bolts require a metric allen wrench, which I was using)... This was a major PITA for me b/c it took me over an hour to remove these bolts and now I need to find some replacement bolts at Lowe's or Home depot before I continue with this installation. The threads look ok on both bolts, so I think perhaps the factory overtightened these bolts when they originally installed them b/c the P650 service manual says to torque them to about 8.6 foot lbs. Anyway, I thought I should post this so that others will be prepared for a similar problem when they do the cam upgrades. NOTE: I still have to remove my front camshaft and camshaft sprocket bolts...wish me luck!

If anyone (who has already done a cam upgrade) has any suggestions on how to remove these camshaft sprocket bolts without rounding off the heads, PLEASE LET ME KNOW ASAP!


Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

I plan on doing a cam upgrade this winter.

 

KOD,
With the use of DWB's excellent write-up on cam installations and the P650 service manual, I have to admit that its been a fairly easy mod up to this point (problems with Camshaft sprocket bolts). In 3 hours, I was able to remove front fender and middle gas tank plastic, cvt cover, cvt intake, cvt exhaust, pull rope cover, airbox, carbs, both valve covers/rocker cases and pull out the rear camshaft. I was a little concerned about finding TDC, but now that I've done that, I think this mod is a little easier than I had imagined it would be (except for those darn bolts on the camshaft sprockets). I expect the next big hurdle for me will be adjusting the valves after I get both cams installed...it looks like there's not much room to get a feeler guage in there and be able to see it well).

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Im hoping it wont be to much trouble. If I get a good price on a bore job plus the othe work I may let someone else I have in mind do this for me.

I checked my valves before and you dont have much room to work with. You will have to bend the tip of your feeler guage to get it in there.

 

i checked my valves over the weekend. like kod said you have to bent the tip of the fealer gauge over. i also took the .009"(ex) and .005"(in) off of the main body of gauges, less to hold and wiggle around to get it in their.

good luck mikeyboyesq. let us know how she runs after you getter done.


______________________________
02 650p
see pictures for mods

 

Happy, happy, joy, joy! [img]i/expressions/face-icon-small-smile.gif[/img]

UPDATE: Last night I installed the rear v-force cam (using new cam sprocket bolts which I found at Home Depot...but I had to file off 2 mm in length to make them identical to the stock screws) and I also installed the front v-force cam too. Lucky for me, I was able to get a good grip on the front cam and break the cam sprocket bolts loose without having to use the torch I bought yesterday. In fact, I did not round off the cam sprocket bolts at all on the front cams! Yippie! [img]i/expressions/face-icon-small-smile.gif[/img] I was also able to reinstall the cam chain tensioners & rocker cases and also adjust the valves before I called it a night. I did the best I could, but I'm not 100% confident that I did a perfect job adjusting the valves. There is really not enuf room to work the feeler guage in there smoothly and its very difficult to see sometimes. I guess I'll know when I start it up if I did it accurately enuf to run good...hopefully no tapping sounds!

As of now, I have a total of 9.5 hours into this mod and the only thing left is reinstalling the carbs, airbox, fenders, cvt covers, etc. So in theory, I should have it back together in about 3 hours tops (including time to clean up the parts before re-installing them). Without the problem I had with rounded off heads on the cam sprocket bolts, I'm guessing this job would take me about 11 hours to do...but I have no doubt it could be done a little faster as this was my first time to do cam installations on any motor other than a go-cart.

I can't wait to get it all together and try it out!

CAM LOBE SPECS:
For what its worth I measured the lobes of the used, stock P650 cams that I removed and the *USED* stock v-force cams that I installed and here is what I found.

P650
REAR EX...1.3994
REAR IN...1.4003

V-FORCE
REAR EX...1.3997
REAR IN...1.4005

P650
FRONT EX...1.3991
FRONT IN...1.4004

V-FORCE
FRONT EX...1.3994
FRONT IN...1.4003

As I discovered with my other post, cam lobe height specs are only good to show cam lobe wear and both cams above were above the minimum allowed cam wear (aka service limits). In theory, **IF** both cams above had their cam lobes positioned on the EXACT same place relative to the cam shaft, then you could equate the taller v-force cam heights above to slightly more lift than the P650 cams. However, it is unfair to compare these two in that manner without confirming that the cam lobes are in fact positioned exactly the same on their cam shafts...so I won't draw any conclusions from these measurements except to say both sets of cams are within the service limit and that there is at least a possibility that I will have slightly more lift with these used v-force cams than with my old P650 cams.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

just a question mikey. are you going to install the 4* key while you have it torn down?


___________________
02 650p
see pictures for mods

 

Deerchopper,
Actually, I'm not planning to install the 4* key. I'm pretty satisfied with the Dyna cdi's 33* max timing and I'm not yet convinced of any significant gains to be had by going with the additional 4* If more people post that they noticed a significant improvement with the cdi plus 4* key, then I'll reconsider doing it at that time. For now, I can't justify buying a wheel puller and going thru the trouble to tear it down for the key installation when I already have 33* max timing.

NOTE: I did not have to tear down that side of the motor to do the v-force cam installation (except for the pull rope that I removed).

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

I though I was slow getting things, come on get that thing running I want to know if it's worth the time.[img]i/expressions/face-icon-small-smile.gif[/img]

 

I was very pleased when I put the v-force cams in. It was a simple process. If I remember corectly antoher guy and I did it in about 3 hours. It was well worth the hp gains for a realtively inexpensive upgrade.