Performance question for Johnson 200

[sanelson]

The motor is a 89 Johnson 200 J200xcea 02272209 on an 89 20.5 Wellcraft Steplift cuddy. The compression on it ranged from 75 to 90 when I had a carb fire and melted 3 carbs. It was replaced with a 225 carb of unknown year. It came with 72 jets, were replaced with 62 jets, and finally with 57D's. At that point it was running 5800 rpms, and 40 mph. with a 14x19 stainless Michigan match. I decided to have it remanufactured in Englewood for the 2 yr warranty, and the notion that it would stop nickle and diming me to death. Electronics are not changed out with the remanufacture. Is there anything I can do, or have the guys remanufacturing the motor do to increase performance in any substantial way?

 

[Dhadley]

Re: Performance question for Johnson 200

I would be very leary of changing jets that far unless you know for sure where the carbs came from and what the originals were supposed to be. <br /><br />But to answer your performance question -- yes, there are a couple of very simple things to do to increase torque. But -- theres always a but -- you would have to run high test fuel. And truthfully, those V-20's dont respond to small torque increases. They run very well pretty easily but to get a significent increase is not that easy.<br /><br />However your running almost 30% slip now. We need to cure that with set up and props, not horsepower. Getting you slip percentage down to even 15% should put you over 45 mph.<br /><br />All this is assuming that 5800 and 40 mph are correct with your 19" prop.

 

[sanelson]

Re: Performance question for Johnson 200

The guys doing the remanufacture want to leave the jets as 57d's as long as I'm getting 58-6000 they said its relly trial and error at this point. The 62's were running very rich at about 4800 to 5000. Would it be better if I email you directly once I get the boat back and can run some performance tests?

 

[sanelson]

Re: Performance question for Johnson 200

I guess I should be more clear, what I'm really looking for is top speed, and higher cruising speed, not low end torque. I'm not pulling any skiers or tubes, just trying to get out to grouper holes.

 

[Dhadley]

Re: Performance question for Johnson 200

Youre overpowering your "bite" now. Adding more power (however you want to measure it, torque or horsepower) will just raise the percentage of slip with very little or no increase in efficiency. <br /><br />The bottom line is that at best youre only using 70% of whats available now. I'd work on that first rather than be restricted to high test fuel.

 

[sanelson]

Re: Performance question for Johnson 200

Could the motor be mounted too high? The cavitation plate is about 3/4 to 1 inch above the lowest point on the hull. One guy said it was mounted 1 hole too high, then a half dozen others said it was ok.

 

[Dhadley]

Re: Performance question for Johnson 200

It may be mounted a bit high for a Michigan wheel. It's possible, especially if its worn at all or has been rebuilt.<br /><br />The mounting height (X dimension) depends on the technology built into a prop and how it reacts with any given hull.