Thread: Breaking in a 1300 ported motor.
08-20-2007, 04:30 PM #1
Breaking in a 1300 ported motor.
Just got my single back together and was able to put 3 hrs on
it after putting in a new crank, oem pistons and having Lowell port my cases.
I also got my crank from Lowell which was rebuilt from crankworks
with a big molly bearing. I wish I could show you how awesome it looked
compared to the stock one.
I turned the fuel up so high that the ski burned its first tank of gas in 48 miles running mostly around 4000 rpms.
I did to short bursts wide open every once in a while. I put a small prop on ski so It would not load the motor.
After 2 full tanks of gas I checked the compression and there is 20 lbs difference between number one and number 3. Three being lower. I have it set up so the rear is 10 lbs less than the other two.
I guess the rings are still not broke in after two tanks.
08-20-2007, 04:54 PM #2
I paid Lowell $20 to lower the compression in your #3 cylinder. Keeping my ducks in a row for MB4
08-20-2007, 05:11 PM #3
I think 20psi is alittle much. Did you do a compression check b/f you broke it in>?
08-20-2007, 07:00 PM #4
- Join Date
- Apr 2006
- South MS
I'm no expert on this, but I think you need to gradually lean it down some and do longer runs on it. 3hrs at a very rich setting probably will not heat it up enough to fully seat the rings. Maybe some of the more experienced will chime in...
08-20-2007, 07:28 PM #5
Charles, I agree 20 lbs is a lot. I did not check before I ran.
Lowell says to ride it hard right away to seat the rings. But, after 13 years
of riding alot I have stuck a few pistons. I think if you are going to run 120 to a 150 hrs a year a mild break in works for me.
Before rebuild I was 160/160/150. I had to send the front cylinder to millinium to get re done. Last night it was 165/ 160/145. I checked each
hole 3 times back to back 2 seperate times.
I also added 16 ounces of oil per tank along with the stock oil injection.
Which Jims performance recomends I do.
I know the compression is going to come up and will let you know at 6 hrs.
08-20-2007, 07:38 PM #6
I would ride it like you stole it to build some heat in those cylinders and then check it.
08-20-2007, 08:18 PM #7
08-20-2007, 08:21 PM #8
Yea i would just go and warm it up really good and then run the crap out of it... Atleast get it to peak then slack back down several times.
08-20-2007, 09:01 PM #9
08-20-2007, 09:08 PM #10
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