zuke df250 twins repower

[Nail-it]

hey guys I repowered my 300 marlin with df250 (not fly bye wire) I have 300rpm diff. between port and starboard engines at wot.any thoughts what could be problem.

 

[JJF]

Cabling issue/adjustment perhaps...

 

[ElyseM]

add: fuel lines & filters, trim, props to specs, gauge (swap sides see if it follows), etc.

good luck

 

[Sardinia306Canyon]

New DF250 or older ones?

 

[Nail-it]

Cabling issue/adjustment perhaps...

Dealer adjusted tps.to make same also cables. No change.

 

[Nail-it]

add: fuel lines & filters, trim, props to specs, gauge (swap sides see if it follows), etc.

good luck

I am taking props to shop make sure they are the same. I did gauge swap.fuel lines and filters all new. I am hoping it’s the props,3x16x18 1/2 Suzuki props.

 

[Nail-it]

New DF250 or older ones?

2023 new out of box in February,dealer installed

 

[Sardinia306Canyon]

For new engines i would set a engine problem back on the list, however i think 250HP twins are on the lowest end of the power for a Marlin, and with slightly too high pitch a small detail can have a big effect.
on the affected side there may be

• different propeller than the other
• something on the hull what is breaking the affected side (thru-hull transducer for example)
• more uneven antifouling
• trim tab not totally retracted
• slightly different engine trim
• more weight on affected side

My 306 Canyon with twin F300 has 15.5x17 props and they are a tad too much pitch.
If i repower with twin DF300AP i expect that the 16x18.5 is a tad too low pitch and 16x21 a tad too long.
I would do a test with the WaterGrip16x17 propellers, that may solve your problem with lower rpm.
In case 16x17 solve the rpm difference but unsatisfactory speed/economy results then you may use a different propeller than the Suzuki ones.

What rpm at WOT do you reach now?
Does the boat list slightly to one side?
Do you have a big thru-hull /transom mounted transducer (or any other protrusion) on the affected side?

Chris

 

[JJF]

Have both engines been fully broekn in?

If so, my next guess would be a fuel restriction/air leak... can the feed lines be swapped?

 

[Nail-it]

Have both engines been fully broekn in?

If so, my next guess would be a fuel restriction/air leak... can the feed lines be swapped?

80 hrs I will have to wait till spring on fuel lines.yes I can swapped.dealer did put fuel pressure gauge on it at idle and wot said it was perfect.

 

[Nail-it]

For new engines i would set a engine problem back on the list, however i think 250HP twins are on the lowest end of the power for a Marlin, and with slightly too high pitch a small detail can have a big effect.
on the affected side there may be

• different propeller than the other
• something on the hull what is breaking the affected side (thru-hull transducer for example)
• more uneven antifouling
• trim tab not totally retracted
• slightly different engine trim
• more weight on affected side

My 306 Canyon with twin F300 has 15.5x17 props and they are a tad too much pitch.
If i repower with twin DF300AP i expect that the 16x18.5 is a tad too low pitch and 16x21 a tad too long.
I would do a test with the WaterGrip16x17 propellers, that may solve your problem with lower rpm.
In case 16x17 solve the rpm difference but unsatisfactory speed/economy results then you may use a different propeller than the Suzuki ones.

What rpm at WOT do you reach now?
Does the boat list slightly to one side?
Do you have a big thru-hull /transom mounted transducer (or any other protrusion) on the affected side?

Chris

6000 on port
5700 on starboard
No
No
I am going to have props checked,make sure they are both 18 1/2 pitch. They gave me another prop no change take to shop at thanksgiving.

 

[Fishtales]

Strange indeed wondering if it is the motor itself. Is there an RPM limiter?

 

[Sardinia306Canyon]

6000 on port
5700 on starboard
No
No
I am going to have props checked,make sure they are both 18 1/2 pitch. They gave me another prop no change take to shop at thanksgiving.

Oh, i am positively surprised that the 300 Marlin does 6000 rpm with the 16x18.5 prop, so i probably can go 16x21 with twin DF300AP and that would be perfect!

I am curious what the prop shop measures, there are some voices saying that Suzuki and Solas props can be with pitch slightly off, what i never experienced but does not exclude.
If the props are identical in pitch then i would still look on the boat or hull and have the dealer doing a full check-up of the engines.
Chris

 

[Nail-it]

Strange indeed wondering if it is the motor itself. Is there an RPM limiter?

Yes I had 17 pitch props at first set of rev limiters at 6200 changed to 18 1/2 on 20hr service.5950 wot both motors.used 3 weeks spun both props got new ones on warranty now 300 rpms difference.changed prop on motor not getting 5950 still the same. That’s why I am talking props to shop next week. Dealer won’t return my calls or emails to resolve issue. Never do business with Stateline Boat Works in Rhode Island again.had no problem taking my money for repower but don’t want to resolve issues. Poor business practice.

 

[Nail-it]

Oh, i am positively surprised that the 300 Marlin does 6000 rpm with the 16x18.5 prop, so i probably can go 16x21 with twin DF300AP and that would be perfect!

I am curious what the prop shop measures, there are some voices saying that Suzuki and Solas props can be with pitch slightly off, what i never experienced but does not exclude.
If the props are identical in pitch then i would still look on the boat or hull and have the dealer doing a full check-up of the engines.
Chris

Ya they don’t seem to want to resolve issue.won’t return calls or emails,Stateline Boat Works in Rhode Island. I will let you know what prop shop says.