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6500 RPM Maximum on 252XE

jemorgan3

Jet Boat Lover
Messages
17
Reaction score
6
Points
82
Boat Make
Yamaha
Year
1999
Boat Model
LS
Boat Length
21
Having a RPM issue with my 252XE that I can't figure out. Ive replaced the impellers with impeller.com upgrades, replaced the plugs with LFR6A's and confirmed the oil level is good on both engines. Before all that, I was limited to 6500 rpm.. And after all the maintenance, still limited to 6500!!

Am I overlooking anything? im topping out at about 38 with just me on calm water..

Tried to look at making sure the throttle cable was adjusted correctly, but the E-series boats dont seem to have a cable at the throttle body. Do we have the ability to adjust the rpm on E boats?
 
IDK, but have you tried cruise assist? If the issue is your throttles, can you increase the RPMs that way? Looks like Cruise Assist functions up to 7k RPM.
 
I suspect you put in impellers with too much pitch. Especially if the engines were running at full rpm before you put those impellers in.
 
was limiting at 6500 before the new impellers as well.
 
Indiana and Kentucky, altitude shouldn’t be the problem as we are between 300-500 ft at all the lakes we visit.
 
Indiana and Kentucky, altitude shouldn’t be the problem as we are between 300-500 ft at all the lakes we visit.
Give us tye history on this boat. Your signature says 1989 LS 21…
Buy new or used?
Hours?
Why did you put in new impellers?
Etc etc…
 
80 hours, 2022 252 that had wear in the stock impellers. Has only hit 6500 rpm in the 5 outings I’ve owned it for, before and after the impellers and additional maintenance.
 
80 hours, 2022 252 that had wear in the stock impellers. Has only hit 6500 rpm in the 5 outings I’ve owned it for, before and after the impellers and additional maintenance.

Okay, so when you bought the boat it had worn impellers and it only hit 6500 rpm. If you have excessive wear in the impellers it will not seal properly and the engines will typically max out rpm wise and you will have cavitation. Please tell us about how the impellers were excessively worn. Did you have the ones you took out?

This boat has the normally aspirated 1.9L engines correct?

I would check the air boxes for cleanliness then on your next outing make a speed run, then pull the air filters and see what happens. I see that you have checked the oil levels which would be my next suggestion.

I would also suggest checking that you got the correct pitch impellers, check with Leading Edge or Impros, because all things being equal, it sounds to me like you are over propped/impellered.
 
Since the impellers that can out were stock, and I had this 6500 rpm limitation with the stock impellers, the new ones are not the issue.

The 2022 252 has the 1.8L motors, and with new wear rings and impellers, it has no cavitation, at least none that would cause this.
 
My suspicion is that the throttle cables are not set correctly, but the adjustment procedure is not the same as the non E boats.. and I can’t seem to find the e series boat procedure at all
 
let us know what you find out..
 
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