21 CC Repower

[Sail Away]

I'm fairly new to this site and haven't contributed much yet. So, I will really appreciate any information and advice to my repower question.

I've owned a 2002 21 CC with a 225 Optimax for about a year. It has a Mirage Plus 19" pitch prop. The Optimax pushes this boat loaded with 70+ gallons of fuel with 2 on board at over 40 knots at WOT and is surprisingly stable even in a moderate chop. Although the powerhead is very strong, the motor has not been well maintained and is unreliable. So, I'm considering repowering. I'm looking at the usual suspects:

another Optimax 225 (500 lbs)
Yamaha 200 HPDI (475 lbs)
Yamaha F225 4.2 L (568 lbs)
Honda 225 (600+ lbs)
Evinrude 225 ETECH (525 lbs)
Maybe something smaller.

The Opti and Yamaha HPDI are lowest repower cost and lightest. I am afraid to go much heavier. But, reliability is also important to me.

I'd appreciate how others have repower their 21 CC's and their satisfaction levels.

Thanks a lot.

[gofastsandman]

Some 4 strokes have exhaust corrosion issues. f225 is one.

Not a cheap fix. You don`t need a ton of hp. Light is right.

Cheers and welcome,
GFS

[FishStretcher]

Assuming this is the stretched 20, I get 34 mph on a four stroke 100hp Yamaha on a 20 footer. Plus there is weight budget left for a kicker. Kicker and main motor are under 430 lb. And 5MPG or better.

[PigSticker]

Anything under a 200 would be underpowered on a 21, im not sure they ever even sold them with anything else...HPDI or E Tech would be nice, the Honda has the worst weight to power ratio out there

[wattaway2]

the newer 21 is more of a short 23 than a long 20

[bgreene]

150 or 200 opti ...........still fine. Merc fine tuned the opti since your model and they have a reputation for great fuel economy and power.

Etec and Yami hpdi good too. Either of these three and you'll be very good to go for a long time....

[77SceptreOB]

Originally Posted by wattaway2

the newer 21 is more of a short 23 than a long 20

Yep! There is a lot more hull in a newer 21' than a std Moesly/Potter 20', and thus more power is needed...

[FishStretcher]

Originally Posted by wattaway2

the newer 21 is more of a short 23 than a long 20

Thanks for the clarification. My comment doesn't apply then. I thought the panels and deadrise were the same, just extended.

[countshock]

Zuke 250 at 580 lbs?

[pair of jacks]

I have a 2001 21 that came with a 200 opti- the motor had issues with false alarms going off and the like which made me lose confidence in it. So, I went with an E-tec last summer. Now, I always thought I was overpowered with the 200 opti and since they sold the 21 with 150 standard on it not long after I bought mine, I went with a 175 E-tec. It IS underpowered. I do about 30 kts @5500 rpms which is fast enough for me, and cruise is 24 knots @ 4800 rpms- all of which is fine. But you can tell that the engine is working- with the opti I almost never went above 4100 rpms and cruised at the same speed with a Mirage 17 pitch prop. Don't get me wrong- I do like the E-tec- it's very quiet and I've only had a minor issue with the fuel mgmt. sensor to date (throu 130 hrs.) but in retrospect, I probably should have gone with the 200 E-tec. The 21 is difficult to repower since, in my view, 4 strokes are too heavy for an already ass heavy hull, and I didn't want to go back to a Mercury because of my issues. I lost about 100 lbs off the back going with the E-tec while I would have GAINED 100 going 4 stroke. Nothing with a boat is easy!