Thread: Ready to start???
04-12-2008, 09:38 AM #1
Ready to start???
I'm re-fitting my head, it has the RR cam.
- The cam and crank were locked,
- cam chain tensioner is in,
- cam gear bolts are in,
- I can turn it over by hand,
Here is a pic of the cam gear marks, this is as close as I could get them to parallel with the head surface.
Also when turning the engine over by hand the valves pop-up on the springs every third of a turn, I assume this is normal due the spring tension?
So is it ready to fire?
04-12-2008, 10:00 AM #2the valves pop-up on the springs every third of a turn
What does this mean exactly?
04-12-2008, 10:10 AM #3
It looks like it is retarded on the cam sprocket. Have you tried advancing the sprocket on the slotted holes? Hard to tell from the second picture. With the RR cam, you will need to advance it almost the whole way on the sprocket in order to achieve 135 compression. That would be the "sweet spot" for that cam. Maybe try advancing a tooth on the gear and then see how it sits.
04-12-2008, 10:21 AM #4
Steve, I undertstand that I need the comp at 135psi, I just wanted to make sure it would run as is before I started checking compression etc. I will try advancing it a tooth, but I think I have tried this and the tensioner was too tight.
04-12-2008, 10:33 AM #5
Grant, you have that Rotax Racing cam retarded. You need it advanced.
1) Lock the cam with the cam locking tool
2) make sure #3 is on TDC and no crank locking tool
3) make sure sprocket bolts are semi loose
4) rotate the driveshaft clock wise slightly until the right hash mark on the sprocket is slightly lower. This will put the sprocket bolts a little farther to the left in the slots. Don't go all the way but the bolts should be midway between all the way to the left in the slots and the halfway point in the slots.
Now your cam is slightly advanced.
5)tighten your sprocket bolts and remove cam locking tool.
6)install and tighten up tensioner.
You will know you have the cam timing right when you get 135 psi of compression.
04-12-2008, 10:35 AM #6
Thanks, I will do it now.
Can you just confirm the valve springs popping back up when turning over by hand is normal?
04-12-2008, 10:41 AM #7
This is normal. The valves open and close as you rotate the crank.
04-12-2008, 10:48 AM #8
Thanks for confirming, I have now advanced the cam adn it now looks like this...
Good to go?
04-12-2008, 10:49 AM #9
P.S. What are the torque specs for the cam gear bolts and is loctite requied?
04-12-2008, 04:13 PM #10
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By yogski in forum Sea Doo Open DiscussionReplies: 1Last Post: 12-27-2012, 10:10 PM
By jayzhonda in forum Honda Open DiscussionReplies: 21Last Post: 07-01-2010, 11:29 PM
By warsawspeedfreak in forum 4-Tec PerformanceReplies: 10Last Post: 03-22-2010, 04:27 PM
By birel33 in forum Yamaha PWC Performance (2-stroke)Replies: 3Last Post: 07-14-2007, 05:15 AM
By Compwhiz82 in forum 4-Tec PerformanceReplies: 1Last Post: 05-26-2005, 02:19 PM