CD 25D Repowering

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Dick Kobayashi

CD 25D Repowering

Post by Dick Kobayashi »

I am considering repowering my CD25D which has the original 9hp Yanmar. Why? I have owned the boat one season and cannot get the rpms up to 3600 - tops is 3000. and I want the comfort of reliable power ans adequate power to move the boat at hull speed in all conditions. I am considering repowering with a larger engine. If any one has advice or experience to share along thes lines, I would be very appreciative.
Dick K
CD25D SUSAN B Mattapoisett, MA



kobayashir@aol.com
Ray Worthington

Re: CD 25D Repowering

Post by Ray Worthington »

Dick: I literally got my 25D hull #30 Halcyon back from the diesel mechanic today. It now has a rebuilt Yanmar 2GMF engine (13 horsepower model). The results of repowering are spectacular!!! Six knots at 2500 rpms against the tide. The rudder is more responsive. The whole boat seems to have a more solid feel. The mechanic had to lengthen the engine beds about three inches but other than that, a 2GM fit right in and linked to the shaft. I also put on a 13/12 prop for more thrust. Finding an engine may be the most difficult part of your repowering. I found this one through Boat Diesel's site. Happy hunting, Ray



acw@thebest.net
Ken Cave

Re: CD 25D Repowering

Post by Ken Cave »

Sounds like your prop doesn't match your engine, thus lugging at higher RPM's. You might look at the pitch and see if it indeed matches the power of the engine before you begin to purchase an EXPENSIVE engine!!

If you have a two bladed prop, you might also go to a three bladed prop. They are far more efficient due to the full keel.

Ken Cave
Dragon Tale CD 28#227
Anacortes, WA.



bcave@whidbey.net
Keith

Re: CD 25D Repowering

Post by Keith »

What is the weight difference between the 1gm and 2gm Yanmar?

Ray Worthington wrote: Dick: I literally got my 25D hull #30 Halcyon back from the diesel mechanic today. It now has a rebuilt Yanmar 2GMF engine (13 horsepower model). The results of repowering are spectacular!!! Six knots at 2500 rpms against the tide. The rudder is more responsive. The whole boat seems to have a more solid feel. The mechanic had to lengthen the engine beds about three inches but other than that, a 2GM fit right in and linked to the shaft. I also put on a 13/12 prop for more thrust. Finding an engine may be the most difficult part of your repowering. I found this one through Boat Diesel's site. Happy hunting, Ray


kwoodlaw@arkansas.net
Vinnie

Re: CD 25D Repowering

Post by Vinnie »

Dick,

I have a similar problem, but my G1 will only get 2400 RPM in forward. Reverse is fine 3600 RPM. I had the bottom cleaned this week. The diver said that the prop was coated with "barnicles". He cleaned the prop and said that the barnicles would load down the engine and cause the prop to lose efficiency. I'll let you know the results after this week end.

Vinnie

S/V OSPREY
Haul #86
Dick Kobayashi wrote: I am considering repowering my CD25D which has the original 9hp Yanmar. Why? I have owned the boat one season and cannot get the rpms up to 3600 - tops is 3000. and I want the comfort of reliable power ans adequate power to move the boat at hull speed in all conditions. I am considering repowering with a larger engine. If any one has advice or experience to share along thes lines, I would be very appreciative.
Dick K
CD25D SUSAN B Mattapoisett, MA


vgennaro@wpmedia.com
Ray Worthington

Re: CD 25D Repowering

Post by Ray Worthington »

Keith wrote: What is the weight difference between the 1gm and 2gm Yanmar?
Keith: I think that I am close to correct in telling you that the weight difference is about 70 pounds between the 1GM and the 2GM. The only weight difference I notice in the my boat now with the 2GM is that the exhaust is about a 1/2 inch deeper under the water than with the 1GM underway at 2700 rpms. Otherwise, she seems to squat as she usually did. Ray





acw@thebest.net
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