Left engine RPM high

[gearren]

Doing work on a 95 speedster, and the left engine revs to 7500+ RPM at WOT, kicking in the rev limiter, right engine if fine. On the advice of Impros, I replaced the impellers with Solas 14/19 "i" on the left and 15/20 "j" on the right. New wear rings, new carrier bearings as well as rebuilt the carbs. It has a single water intake that feeds both pumps, could this contribute? It accelerates great, real strong, no cavitation, no hesitation. Any ideas why the left engine out revs the right? Anything I can I do about it?

[1fastski.com]

why do you have the smaller prop on the side that has the over reving prob ? swap props i know one is bigger then the other on the twins .

[Bill O'Neal]

7500 rpm on a stock rev limiter?

[gearren]

My error..RPM is close to 7000 RPM on left according to the tach around 6600 on right. I installed the impellers as per IMPROS instructions. According to them, the left loads heavier than the right, ergo the greater pitch on the left. If that is true, then swapping them would result in even higher RPM on the left..? What I hear is the left engine misses slightly at WOT, I'm assuming that miss is the Rev limiter kicking in.

[george]

You've put the lower pictch on the left, if
you typed it in correctly.

You ought to use 'port' and 'starboard' by the way, to avoid the question of which way you are facing when you call one 'left'..

[1fastski.com]

for those who failed BOATING 101 lol port is left starboard is right , easy way to remember is port and left have 4 letters :)

[gearren]

Thanks for reminding me of the importance of using nautical terms. I followed the recommendation of the pros at IMPROS and put the 14/19 on the port engine. I'll pass it back to Impros to see if they got their port and starboard mixed up. They used left & right, which, as you stated, all depends on how you are looking at the boat! . Thanks

[gearren]

I contacted IMPROS, who agreed that the RPM indications point to swapping the pumps, even though their data has the 14/19 "I" on the port engine. So I swapped the pumps, and both engines are matched at 6800-6900 RPM @WOT! Now they don't spool up at the same rate, but I think with some carb linkage readjustment, I can resolve that. Thanks everybody! This forum is fantastic!

[1fastski.com]

if there a little off on revin up its normal on that boat , as one motor has more of a load then the other . if there off at WOT then ajust as needed . good to see you working :)