2000 21i runs like <**>

[ram08]

our 00 21i hasn't really run right since we got it last summer. hard for it to pull with 4 to 5 bodies on board. seems like this year it is worse the more you go the slower it goes,banking in turns it really bogs down. don't know what prop it had before we put another one on at the end of season last year. we did replace the impeller this year, and low and behold found pieces of 5 fins, only 1 missing from the current one..guess somebody didn't read the one about clearing the hose when your r&r impeller. would love help since we can't get another boat with all this change going on.thanks ram 08

[NICKYPOO]

Sounds like a fuel filter or possibly debris in the tank.

You shouldn't have any fins missing on the impellar.

[svtcobra50]

Yup, sounds like fuel filter.

[chpthril]

our 00 21i hasn't really run right since we got it last summer. hard for it to pull with 4 to 5 bodies on board. seems like this year it is worse the more you go the slower it goes,banking in turns it really bogs down. don't know what prop it had before we put another one on at the end of season last year. we did replace the impeller this year, and low and behold found pieces of 5 fins, only 1 missing from the current one..guess somebody didn't read the one about clearing the hose when your r&r impeller. would love help since we can't get another boat with all this change going on.thanks ram 08

1st, welcome to the forum

Ok, if i'm reading this right, the boat performs worse this year, and the only thing that has been done was a prop change.

Couple of questions: hate to ask, but what prop did it have, what prop is on it now, what engine and transmission, where do you live/boat as altitude will have an effect on engine performance and prop choice?

Can you describe how the engine is running: skipping/missing, surge, sluggish, tip-in hesitation (pauses for a second when the throttle it pushed). The symptoms can help pin point causes.

[ram08]

thanks, 350 mag mpi ski. we bought the boat used so not sure on maintanence before. we knew the impeller was in need of r&r the housing was cracked , we found the remains of previous impeller fins ,someone was bad housekeeper, when we did ours. we're in central texas, hotter than hades the last few weeks but not much else.according to youngest son boat was ihow, a tur# from the get go. we only really noticed it this year. wot is 20 to 24 mph. banking turns bogs way down . we have replaced the fuel filter,run lucas thru it,taken off breather and are currently checking fuel pressure. that runs 30 to 32 #s with or without regulator hooked up.checked oil,looked dirty not milky,as i said earlier r&r impeller. we replaced prop last year,sneaky stump,clueless as to exact prop specs..did not know there were so many,hey it fit so we used it although it really isn't performing any differently since the change. we really seem to be going down the fuel reg. route...didn't someone say you should get more #s with vaccum hose disconnect? help please,much appreciated...

[ram08]

Fuel stabilizer, injector cleaner used, boat starts right up, idle's fine and smooth, runs smooth, just will not go faster than about 27 miles per hour, we took the flame arrestor off yesterday while running 27 miles per hour and for just a few seconds the engine idled up, speed jumped up 2 miles and hour and then went back down to 27 miles and hour. I have pulled the water / fuel seperator off and changed, no water or debris noticable. I have read on an automobil that if you disconnect the vaccume hose from the fuel regulator that you should get an increase of 5 to 10 psi at the fuel rail, when I do this there is no difference.

[TeamAllen]

What is the RPM at WOT?

[ram08]

about 3500 RPMs

[TeamAllen]

That sounds too low. Check on top of your spark arrestor. It should give you the optimal RPM range at WOT.

Mine is 4400-4800 RPM @ WOT. I would imagine yours is similar? The way to change that is with a new prop.

[Waterski-Rebel]

I agree. Find out what your WOT is, and call ACME. They will help you figure out what prop you need.

[chpthril]

X2, my gut says that's about 1K low. Like Rebel said, call Acme, just make sure you know what ratio the trans is, this sounds like where the problem is. Once you got the correct prop, retest.

[ram08]

The WOT RPM reads 4600 to 5000. What prop would you recomend?

[ram08]

prop size

the prop that we put on the boat is 13 x 12.125 LH 1-1/8(Acme 579) Not sure why we put this prop on. We found a good price off of ebay and bought it, could it be completely wrong for the boat, anyone have any suggestions on what prop to run for max performance?

[chpthril]

the prop that we put on the boat is 13 x 12.125 LH 1-1/8(Acme 579) Not sure why we put this prop on. We found a good price off of ebay and bought it, could it be completely wrong for the boat, anyone have any suggestions on what prop to run for max performance?

Yes, sounds like wrong prop. Need to know gear ratio, could be 1:1 1.5:1. Best thing is to call ACME or email them using the form off their web page.

[svtcobra50]

I just put a 525 on my 21i and it is grrreat! Tigegirl has some left I think. Cheap too.