Engine distance suggested by GW and source Vinyl bang cap other than GW

[Sardinia306Canyon]

As i am installing the two new Honda BF350 i was "feeling" that the Yamaha F300 were installed a bit too near and a bit more distance would not hurt.
The BF350 will fit the Yamaha engine holes but a bit more distance would give me more maneuverability and i may can install the Hondas one hole higher.
Someone has the original distance or has moved the engines a bit more out?

I have a slight swelling on the edges of the transom cutout and the aluminum bang cap is corroded so i need to replace it.
Solution would be glass over it, a SS angle or a stripe of Vinyl band/stripe, both bedded well with Sika/5200.
The shipyard has a able in-house fiberglasser but i fear new fiberglass it will crack again and water will leak again in, but may overthink.
Not GW as source as it would take too long to order thru Italian Importer so i was looking for something on Amazon.

Chris

 

[ElyseM]

i believe engine placement is based on hull bottom and anti-vent plates positioning. your installer should be able to tell you were they need to be set.

 

[SkunkBoat]

Hondas got big bottom.....

What is your current spread? (measure from one mounting hole to corresponding hole for the other motor)
Mine are spread 28" and that is a typical spread for large V engines with 25" shafts
I know some Whalers had a 29.75" spread.

As you said, if you spread them outward, you have to raise them. There are limits. At some point you need 20" shafts.
There is a formula like tangent of deadrise angle x 1 inch(of movement from keel)= change in height in inches....something like that..don't quote me...look it up...
Measure a dozen times and be sure you can get the right height.

I can't imagine you could spread more than 1 or 2 inches from where you are. Is it worth attempting ?

I guess if you don't have an old school motorwell, what you gain in space between motors won't be lost between sides of motorwell.

The aluminum trim piece is a pet peeve of mine. Like yours, mine has been squished my the motors. It makes ZERO sense to have that between the mounting bracket and the transom.
If you glass it it has to be done with GLASS, not just fairing. After that, you can trim it with whatever...but let the motors contact the hull at top & bottom holes.

 

[Fishtales]

Glass the transom. If it is bulging, you have moisture in it. Get it fixed and glassed. Done right, this is by far the best solution.
As for the Hondas, I'd be concerned about weight addition more than position. My 2 pennies....

 

[Sardinia306Canyon]

As for the Hondas, I'd be concerned about weight addition more than position. My 2 pennies....

There is no big weight difference at all, it's the opposite
804 lbs 2011 Yamaha F350 V8
770 lbs Honda BF350

The 306 Canyon came with the option for the V8 F350, also mine and it has 700HP written on the CE plate

Chris

 

[Sardinia306Canyon]

What is your current spread? (measure from one mounting hole to corresponding hole for the other motor)

Thanks a lot, i will go today or tomorrow and discuss replacing the transom cap and measure the distance and yes i am aware that at a point i would need a shorter shaft what is not a option, but one hole up would be one.
Going too wide will make the hydraulic piston hit the splash well wall and limit how much the engine can turn and i need to consider that.
If i can go only a inch wider then i leave it where they are and use the original holes.
Yes, i know how to place outboards on the correct hight and the shipyard install approx 100 outboards every year so they know even better, it was just a thought that moving the engines a bit outward i may be beneficial, but i need to verify that very well.

If you glass it it has to be done with GLASS, not just fairing. After that, you can trim it with whatever...but let the motors contact the hull at top & bottom holes.

Yes i will discuss this with the glass guy there after we took off the two plastic angles on the end of the cutout.
For this season i probably just use a SS angled bar or a vinyl stripe attached with 5200 to avoid further water seeping in and next winter fix that for good.

Chris

 

[seasick]

Thanks a lot, i will go today or tomorrow and discuss replacing the transom cap and measure the distance and yes i am aware that at a point i would need a shorter shaft what is not a option, but one hole up would be one.
Going too wide will make the hydraulic piston hit the splash well wall and limit how much the engine can turn and i need to consider that.
If i can go only a inch wider then i leave it where they are and use the original holes.
Yes, i know how to place outboards on the correct hight and the shipyard install approx 100 outboards every year so they know even better, it was just a thought that moving the engines a bit outward i may be beneficial, but i need to verify that very well.

Yes i will discuss this with the glass guy there after we took off the two plastic angles on the end of the cutout.
For this season i probably just use a SS angled bar or a vinyl stripe attached with 5200 to avoid further water seeping in and next winter fix that for good.

Chris

I would research the 5200 idea. 5200 is an adhesive and intended for parts that are fixed in place. Parts than can flex or move are better served by using a sealant.

 

[Sardinia306Canyon]

I never had issues with insufficient flex of 5200 or similar Sika and used tons of it over the years for sealing many different things as it adheres better to gelcoat than 4200 and that is basically what would be needed for the transom cap.
The problem with 5200 is that it adheres so strong that parts need to cut off, so if i go with a U shape profile i need to use 4200 or a even less adhesive sealant.
5200 is exactly the same PU as 4200 with the difference that 5200 needs more force to rip two parts apart, same with SIKA.

 

[Sardinia306Canyon]

Mine are spread 28" and that is a typical spread for large V engines with 25" shafts

I was at the shipyard and measured 50cm/20 inch between the two bolts on the inside of the bracket.
Seeing the transom without engines i realised that i can not go wider as then the steering piston would hit the splash well wall limiting steering.
So i will reuse the existing holes.

Chris

 

[SkunkBoat]

I was at the shipyard and measured 50cm/20 inch between the two bolts on the inside of the bracket.
Seeing the transom without engines i realised that i can not go wider as then the steering piston would hit the splash well wall limiting steering.
So i will reuse the existing holes.

Chris

Well the bottom holes are closer together(9-7/8") than the top (12-7/8") so idk what the 20" means.
the measurement to make is from a top bolt of one motor to the same top bolt of the other motor. That will be the same as measuring center of motor to center of motor.
of course, if the motors are mounted, you can measure from tiller to tiller.

 

[Sardinia306Canyon]

Well the bottom holes are closer together(9-7/8") than the top (12-7/8") so idk what the 20" means.

Ups, yes, the upper holes; center upper hole to center upper hole and i needed to use that as both engines are off.
Chris

 

[Fishtales]

There is no big weight difference at all, it's the opposite
804 lbs 2011 Yamaha F350 V8
770 lbs Honda BF350

The 306 Canyon came with the option for the V8 F350, also mine and it has 700HP written on the CE plate

Chris

I was looking at the V6 Yamaha F350.

 

[SkunkBoat]

Ups, yes, the upper holes; center upper hole to center upper hole and i needed to use that as both engines are off.
Chris

that would put you at 32-7/8 centers..... that is awful wide...doesn't sound right but I don't have a 30 fter. Your boat is a foot wider that mine so I guess that might be right....

 

[Fishtales]

May want to check the trim tab location on the 30'ers with the larger engines. May need to relocate aft if performance isn't what you expect.

 

[Sardinia306Canyon]

I was looking at the V6 Yamaha F350.

Yes the V6 Yamaha is lighter,
but a pimped 300 what i don't consider, nor any Yamaha.
If the Bf350 with his V8 did not stay i would have chosen the Suzuki DF300.
Chris

 

[Sardinia306Canyon]

Your boat is a foot wider that mine so I guess that might be right....

Yes i guess it's this, different boats and different widths.

May want to check the trim tab location on the 30'ers with the larger engines. May need to relocate aft if performance isn't what you expect.

I don't see this point, the immersed part is similar and same length as the F300, so i guess if i use the same holes there should be no problem.
And as i wrote above, i can't go wider so i will use the original holes.

However, i installed many outboards on my and clients boats and the only thing what works to verify the hight and spacing is to put them in the water and do a test ride.
Chris