Right size motor?

[Alacat]

I have a 1648 monarch flat bottom that currently has a 2001 25 Tohatsu 2 stroke on it. I'm awaiting parts to repair leaking head gasket at present and while cruising the parts web sites, I looked at the pricing on new motors. The new 25's are significantly higher than the 20's. The new 20 4 strokes weigh about the same as my 25 2 stroke while the new 25 is much heavier. How much fall off in performance would there be changing to a 20 four stroke on my jon boat? Are the 2 cylinder 20's as smooth as the 3 cylinder 25's? Are the 25's really worth the difference?
BTW, Elvin, good to see you haven't lost your sense of humor, LOL!

 

[Sea Rider]

Re: Right size motor?

Why don't you pass your actual 25 to 30 HP and save a ton of money on a new engine.

Happy Boating

 

[pvanv]

Re: Right size motor?

I have a 1648 monarch flat bottom that currently has a 2001 25 Tohatsu 2 stroke on it. I'm awaiting parts to repair leaking head gasket at present and while cruising the parts web sites, I looked at the pricing on new motors. The new 25's are significantly higher than the 20's. The new 20 4 strokes weigh about the same as my 25 2 stroke while the new 25 is much heavier. How much fall off in performance would there be changing to a 20 four stroke on my jon boat? Are the 2 cylinder 20's as smooth as the 3 cylinder 25's? Are the 25's really worth the difference?
BTW, Elvin, good to see you haven't lost your sense of humor, LOL!

Totally different units. The 15/20 2-cyl 4-stroke is carbureted, while the 25/30 3-cyl is EFI. Much bigger, heavier, and smoother. Gotta agree with Luis that if your monarch is light and weight-sensitive, boost your 25 2-stroke to a 30 and enjoy. The 4-stroke power curve is a lot different from your motor, and the hole shot of the old 25/30's is very good. You might end up with a 30 EFI to get the low end you have now.

 

[Alacat]

Re: Right size motor?

Already bumped up to 30. Matter of fact, I remember Elvin calling me either an idiot or a genuis when I told him I reamed out the restrictor to Carb throat size. That was a while back. Uses a lot more fuel now. Could be the throttle position though.

I really wanted to know if there was a significant performance letdown with the new 20hp since that's all I can buy online and no local dealer to ship to for the 25. Gonna have to get a new one someday I guess. Electric start is something I'm beginning to miss and 600 for a kit for mine doesn't make sense to me.

 

[pvanv]

Re: Right size motor?

The 3-cyl hole shot will be a lot brisker than the 2-cyl. The new 15/20 will be a lot slower than what you already have. Internet dealers can't ship remote control units without actually doing the setup. BUT... A tiller 30 could be shipped.