ZENOAH TUNING

[h20ski]

I picked up a used cat with a 260 mod motor. The motor is giving me trouble. When first starting off, the boat gets on plane but only does about 25 mph. If I back off the throttle, it will start to pick up and get on the pipe. When I'm driving it I'm going back an forth between full and feathering the throttle to keep it going.

This is my first gas boat so I'm still learning but to me its getting way too much gas. Should I be checking both high and low adjustments, high only or what else should I consider

Thanks

Jim

 

[jeff baham]

what carb number is it, 644, 257, does it have a primer bulb on it , now, check the butterfly and see if it is loose, when you start the motor, does the motor rev high or does it chock,gagle fart spit, trying to get to full throttle. ok, on the 644 the high end needle should be 1 1/2 out and the low end is 1 out. can you show some pictures of the motor.

 

[h20ski]

I picked up a used cat with a 260 mod motor. The motor is giving me trouble. When first starting off, the boat gets on plane but only does about 25 mph. If I back off the throttle, it will start to pick up and get on the pipe. When I'm driving it I'm going back an forth between full and feathering the throttle to keep it going.

This is my first gas boat so I'm still learning but to me its getting way too much gas. Should I be checking both high and low adjustments, high only or what else should I consider

Thanks

Jim

I picked up a used cat with a 260 mod motor. The motor is giving me trouble. When first starting off, the boat gets on plane but only does about 25 mph. If I back off the throttle, it will start to pick up and get on the pipe. When I'm driving it I'm going back an forth between full and feathering the throttle to keep it going.

This is my first gas boat so I'm still learning but to me its getting way too much gas. Should I be checking both high and low adjustments, high only or what else should I consider

Thanks

Jim

The carb is a 257. It starts fine and will rev up fine when the throttle is blipped out of the water.

Jim

 

[Don Ferrette]

What size prop & pipe length? What pipe? Stock motor or modded?

 

[Mick J]

As a base line starting point on the WT-257 carbs, I personally use the following:

Low 2 1/4 turn

High 7/8 - 1 turn

This generally gets me in the ball park every time, then it is only minor tweaks here and there for pipe/prop etc etc. Give that a go.

Just remember.....................rich runs.................lean dies

Johno

 

[h20ski]

What size prop & pipe length? What pipe? Stock motor or modded?

Don, I believe the prop is 6717 two blade. The pipe is a C & C with a 2" band. Motor is modded by Larry Broman.

Jim

 

[riph]

What size prop & pipe length? What pipe? Stock motor or modded?

Don, I believe the prop is 6717 two blade. The pipe is a C & C with a 2" band. Motor is modded by Larry Broman.

Jim

Open Hi needle until the motor does not sag when you open throttle. Set Lo needle at 2 1/4 and Hi at 1.

 

[h20ski]

What size prop & pipe length? What pipe? Stock motor or modded?

Don, I believe the prop is 6717 two blade. The pipe is a C & C with a 2" band. Motor is modded by Larry Broman.

Jim

Open Hi needle until the motor does not sag when you open throttle. Set Lo needle at 2 1/4 and Hi at 1.

Went out today and had the high at 1. Ran smooth - top end of 50.4. I haven't even started with the set up so I'm sure there is a few more mph out of it.

Thanks for the help everybody.

Jim

 

[jeff baham]

What size prop & pipe length? What pipe? Stock motor or modded?

Don, I believe the prop is 6717 two blade. The pipe is a C & C with a 2" band. Motor is modded by Larry Broman.

Jim

Open Hi needle until the motor does not sag when you open throttle. Set Lo needle at 2 1/4 and Hi at 1.

Went out today and had the high at 1. Ran smooth - top end of 50.4. I haven't even started with the set up so I'm sure there is a few more mph out of it.

Thanks for the help everybody.

Jim

h20ski, for more info to get your boat going faster, check out the guys at jim.s boat dock, they are all gas guys and some like a little nitro, here is all nitro and some gas. plus larry broman is on there very often. fastratfink is his name.