250 Inlnie Throttle

Will Fish

Petty Officer 2nd Class
Joined
Jul 8, 2011
Messages
164
Has anyone ever converted a 3.0L 4cyl throttle/carb/linkage to in inline 6?

I upgraded the old gimbal housing and transom plate to an Alpha 1 form the old pre-alpha. When doing so I had some mods to do, which included the exhaust pipe and riser. The lower exhaust pipe is now offset out from the rear port engine mount of the transom plate, which required the riser to be offset to mate to the lower pipe, hence in the way of the throttle cable routing to the carb. Now i cant get a nice soft bend in the cable either on the outside of the riser or in between the riser and the valve cover :)facepalm: (I forgot to take pictures, but will post in a day or so).

I've come up with 3 options, not too sure which would be best. Your input is greatly appreciated.

Option 1: The only way I see the existing linkage and cable being utilized is to route the cable over the top of the riser, making a bracket to hold the cable in place on the barrell of the cable, and mounting to the carb.

Option 2: I've been searching around at the inline 4's and notice the shift interupter is mounted on top of the valve cover, but could not find a pic of the cable connection and the linkage on the carb, or if I could even do such a modification with this motor?

Option 3: Get a longer throttle cable, route it around the riser, and put a soft loop in the cable and utilize the existing bracket and linkage.

I'm so close to finally finishing and getting the boat in the water and keep running into these damn snags:mad-new::mad-new::mad-new:
 

Aatcman

At-Sea-Man
Joined
Aug 20, 2004
Messages
166
Re: 250 Inlnie Throttle

Sounds like option 3 would be the correct way to do it.

BTW if you ware planning to use the drive that was originally behind the 3.0 you will need to regear it to work properly with the larger I-6
 

Will Fish

Petty Officer 2nd Class
Joined
Jul 8, 2011
Messages
164
Re: 250 Inlnie Throttle

Sounds like option 3 would be the correct way to do it.

BTW if you ware planning to use the drive that was originally behind the 3.0 you will need to regear it to work properly with the larger I-6

I'm thinking the longer cable is the way to go as well.

Sorry for the confusion, but the motor has always been an inline 6 GM 250. The reason I ask if the 3.0 linkage will work was because the 3.0L has the same riser offset. The shift interupter switch is mounted to the top of the valve cover and appears the cables are routed a different way.
 

Will Fish

Petty Officer 2nd Class
Joined
Jul 8, 2011
Messages
164
Re: 250 Inlnie Throttle

I finally was able tro get the throttle in a good position and move nice and smooth. I extended the screw/bolts that are used to install the cable to both the bracket and carb linkage. I used spacers on the longer bolt/screw, and a 15' cable compared to the original 14' cable.
throttle 2.jpgthrottle1.jpg
 
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