Bimini 306 Repower

[Road Work Ahead]

My brother and I are looking into repowering our 2003 GW Bimini 306. It currently has Yamaha 250hp HPDI's and would like to install 300hp 4 strokes. Was wondering if anyone can give us some feedback on their experience with a repower and what brand engine, fuel burn, etc? E-Tec, Verados, Suzuki and of course Yamaha.

Thank you

 

[seasick]

My brother and I are looking into repowering our 2003 GW Bimini 306. It currently has Yamaha 250hp HPDI's and would like to install 300hp 4 strokes. Was wondering if anyone can give us some feedback on their experience with a repower and what brand engine, fuel burn, etc? E-Tec, Verados, Suzuki and of course Yamaha.

Thank you

The maximum HP for that hull is I believe is 250HP. You should check your capacity plate. Overpowering can raise insurance issues.
The new 6 cyl weights about 60 pounds more per engine than the 2 stroke., Older model F300 weigh almost 250 pounds more per motor than the new F300s. ( so older 4s adds 600+ pounds on the transom).
I would be concerned about the older 4s added weight.

 

[Legend]

I have the 2003 GW catalogue and the max HP for the 306 is 500. Twin F250 would be fine for that boat. When I went from an 1995 2 stroke 200 HP engine to a 200 HPDI the performance and fuel saving was dramatic. When I went to my next boat a 283 Sailfish with twin F225 the fuel savings on a per engine basis was a bit better but not dramatic. Love the 4 strokes though. Depending on load probably average 1.6 GPM

 

[seasick]

I have the 2003 GW catalogue and the max HP for the 306 is 500. Twin F250 would be fine for that boat. When I went from an 1995 2 stroke 200 HP engine to a 200 HPDI the performance and fuel saving was dramatic. When I went to my next boat a 283 Sailfish with twin F225 the fuel savings on a per engine basis was a bit better but not dramatic. Love the 4 strokes though. Depending on load probably average 1.6 GPM

I think you are correct. I was thinking twins at 250hp each or 500 total.

 

[bjflink]

I have a 2000 306, repowered with the 4.2L Yamaha F250's. Cruise is 29 mph @ 1.5mpg. WOT (5900 rpms) is 44-45 depending on load @ 0.8mpg. These specs are with bottom paint. Before painting, cruise was closer to 31 and top end was closer to 46-47. Tons of torque and seems to be adequately powered. As a side note, I have the engines mounted on the top hole, and GW is telling me I need to raise them up one hole, which I believe since my cavitation plate is underwater while on plane. I'm told I might pick up another 0.5kt-1kt by raising up....I plan to do this in the next few months. I'll followup with updated #'s.

Let me know if you have other questions.

 

[bjflink]

Another note...I saw a 2002 306 at the dock yesterday, re-powered with Verado 300's. Looked good. Didn't see the owner or I would've asked about performance. Not sure of the Verado 300 weight, but might be over Grady spec.

 

[rpc]

You should take a close look at the Evinrude E tech G2 engines. I spoke to a rep at the AC boat show last year and was very impressed. There is a 500 hr maintenance schedule, high torque, an impressive steering and trim control, plus higher fuel efficiency, it is also about 30 lbs lighter than the comparable 4 strokes. Granted it's my impression of their sales pitch but I think you can't go wrong by taking a closer look.

 

[family affair]

Getting a lot of first hand feedback on this site for your specific application likely won't happen simply do to the number of members. Searching THT might give you a better idea. Posting over there with the same question however, will likely result in a 3-ring circus!
I think all manufacturers make an excellent product in the 300 hp models, each having pros and cons:

Evinrude:
+ total weight
+ efficiency
+ torque
+ maintenance
+ 87 octane
- oil

Merc:
+ quiet
+ efficiency
- weight
- 93 octane for peak performance and efficiency

Yamaha:
+ weight
+ dealer network
+ reputation
- 89 octane for peak performance and efficiency
- expensive maintenance

Zuke:
+ price!
+ price!
+ efficiency
+ reputation
+ 87 octane for peak performance and efficiency
+ lowest maintenance 4 stroke
- weight
- dealer network

The 250 models are more if a mystery. Some are different from the 300 while some are based off of the 300 platform and detuned. Many make the incorrect assumption that detuned = more efficient. Every Grady product with a 4.2 Yamaha 250 always gets worse fuel economy than the 300. This might not be the case with all manufacturers, so do your homework and insist that the dealer will be willing to try different props!

Good luck!

 

[Bread]

When comparing prices/negotiating make sure dealers are including all items e.g.:
De-rigging/removal of old engine; Freight/delivery, Installation/Rigging new engine, cost for controls / gauges, powers steering, new batteries; new fuel hoses etc.

 

[Road Work Ahead]

Thank you for all the feedback. Lots to read, look at and analyze.

 

[Road Work Ahead]

Thank you for all the feedback. Lots to read, look at and analyze.