Thread: Cam timing means EVERYTHING!!!
06-01-2005, 11:41 AM #1
Cam timing means EVERYTHING!!!
This is a lesson i just learned!
As some of you know i have been having trouble getting optimum performance out of my ski ever since i had my head ported and the racing cam installed. It never felt quite right and did not perform up to my expectations. When i first put my head on and lined up the timing marks they were not quite parallel with the head as the manual states they should be as show here:
I never had them quite right as shown here:
In this position the cam is approximately 2 degrees retarded. I was told that the timing marks would never be exactly perfect, but i knew that something had to be robbing my ski of it's power so i stayed persistant and last night decided to dive in and mess with the timing some more.
What i did was put the camshaft holding tool in place locking the cam and then i loosened the cam chain sprocket bolts. I then turned the crank clockwise which in turn brought the timing marks in a perfect position as shown here:
After i tightened the sprocket bolts back up and put it back together i cranked it up and immediately noticed a difference in the way it sounded. It had more of a lope to the idle. It also idled 50-100 RPM"s higher, as before it was a little slow.
I just took a ride on the ski and i noticed a difference immediately upon leaving the landing. I swear my arms must be 3 inches longer now... LOL! I can't believe how hard this thing pulls. It jumps to 8400 RPM so damn fast its scary. Before it took forever to get to 8300 RPM's and acceleration seemed flat. I also gained 2 mph to my top speed.
Im now banging the rev limiter at 8500 and had to feather the throttle to keep from banging it.
Now its time to start playing the repitch game to get it just right. Im now spinning the impeller out of the hole.
Im even contemplating going in and advancing the cam timing a little more to see if i can squeeze anything else out of it
Maybe i should leave well enough alone though... LOL!
06-01-2005, 11:47 AM #2
Great news man! Glad to hear its working out.
06-01-2005, 11:48 AM #3
That's VERY cool Swamp Thing, but now it's time for the skat mods...
Still can't believe someone can tell you "it's just 1 or 2 degs, it's all good"...
06-01-2005, 11:55 AM #4
How relieved you must be - congrats! However now it's going to cost you. I agree with 11, it sounds like you need to focus on the pump. Feathering is no way to ride. I can't believe you're hitting 8500 and having to ease out of the hole.
06-01-2005, 12:08 PM #5
i am VERY relieved! I need to get my Solas pitch just right. In fact, i have one freshly repitched on the shelf right now that was only getting me about 8250 RPM's yesterday. I think with my new found power it will get me to a comfortable 8400 and increase speed..... crossing fingers
06-01-2005, 12:28 PM #6
i would absoulutley go back and do one degree up each time until it was maxed out thast how they do it in the cars ya know ... just go up slowly
06-01-2005, 12:37 PM #7
im going to try it Chris!
06-01-2005, 12:38 PM #8
How difficult is it to get to that part of the engine and do the adjustments? I'm thinking you have that engine cowling on a quick disconnect
06-01-2005, 12:38 PM #9
Great news!... I was finding myself (and I'm sure others, too) checking the message boards regularly, just waiting for the outcome of your trouble-shooting. I'm not sure if I will ever perform the head/cam mod, but if so, I'll do it with confidence because of your openly shared experiences.
Now I can't wait to read about your next adventure with the pump and impeller!
Thanks for the incredible images, they help make everything much easier to comprehend.
Oh yeah, my "stuff" is in... should have it on this weekend
06-01-2005, 12:47 PM #10
- Join Date
- May 2005
- St. Louis MO
Is this something you can do to a stock RXP or does it need to already mods on it first like prop, sc prop, intake ,etc?
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