[hillman1]

I am new to the jet ski world and I have a couple questions. I recently purchased a 98 zxi 1100 and went riding with my son, he has a 99 ultra 150. and I couldn't keep up with him, I realize his has a bigger motor but I thought I'd be able to at least ride with him. Just wondering how fast I should expect my 1100 to go. It was running over 7000 rpm and sounded great just seemed like it should have a little more power. My speedo was a little intermittent but I would guess my top speed was around 50 and my son was running about 65 on rough water. Any suggestions where my power loss might be would be great. Also, I was going to do a compression check and wondering about what I should hope to see there. THANKS

 

[Knightofwyte]

Well the 1100 should be running mid-upper 50's if I remember correctly, but you shouldn't really expect to keep up with your son on the 150.

There are several areas that can cause a lack of performance. You could have excessive wear between the impeller and wear ring or a worn/bent/damaged impeller all of those reduce the pumps efficiency and top speed. Or you could have low compression and power in the engine, or your carbs could be improperly tuned.... Many many possibilities. As for a psi number for the compression check, I believe the 1100 has 3 cylinders which would mean you'd want 120-130 psi in each with no more than a 10% difference between the high and low. If you only have 2 cylinders then you'd be looking for about 150psi, but I'm pretty certain the 1100 is 3 cylinders.

FYI, higher psi rating could mean the engine was modified, not a bad thing really, but if the numbers get much below 120, say towards 110 then a rebuild of the top end might help you out. If they're below 110 then you should be saving for a rebuild r new engine because it will be taking a vacation soon.