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1972 OMC 155 questions - throttle connection?

CBFinet

New member
Hello All,

I've appreciated reading this forum as a spectator for a while having worked on a couple of small boats. I recently acquired an older 1972 BellBoy boat with an OMC 155 hp/Buick V6. It was my grandparents' boat and I'm working towards getting it on the water after sitting for a little over a year since the last time it was out. It looks like some non-original (possibly automotive) parts were used somewhere along the way and I'm trying to get it up to snuff. The hull is in great shape and I'm working on getting the motor and outdrive going. I have a specific question about the throttle linkage at the carb but I'll list what I've done/planned/ordered so far.

From what I've been told (a family friend had the boat for several years) it was run last about 1.5 years ago. It's sitting on a Rolls Axle aluminum trailer so I know that part is good. So far I've pulled the plugs (looked okay) and dumped Marvel Mystery Oil down the cylinders and valve covers. I removed the gas tank and it's at a local radiator shop being boiled out as I type this. I've got a bunch of things ordered with plans on the following:

- replace spark plugs
- oil change and new filter
- clean carb
- replace alternator/fuel pump belt
- replace thermostat and housing gaskets
- install flushing adaptor
- replace water cover gaskets
- replace upper housing seals
- replace impeller and housing/gaskets
- replace tilt gear and trunion gaskets
- replace intermediate housing boot
- drain/fill intermediate, upper, and lower units with Type C lube in the lower unit.
- drain/clean heat exchanger and replace coolant hoses as necessary
- replace fuel lines, filler line, and vent hose.
- new blower motor and vent hoses

So far I've confirmed that the tilt motor/gears are working and the engine cranks. Much of everything else is a question mark at this point. I won't get a ton of time to work on it until Thanksgiving weekend but I'm looking at the throttle linkage at the carb and it looks like something's not right. The throttle cable is attached to the throttle lever/carb by hanging via a small screw. I have the Seloc manual but it doesn't show anything to do with the linkage. Most parts are available so that's good news but I don't know what I need. If anyone has a similar setup that would be willing to take a few pictures I would greatly appreciate it.

Also I'm not 100% that the carb is original. The side is stamped Rochester DualJet 210. From what I've read the carb should be a Rochester 2GV. I'm hoping to order a carb rebuild kit but I'm wondering if I should be looking for a new carb instead.

Lastly I'm still trying to confirm the exact model number. The only plate/number on the outdrive is "155 hp" and I haven't found a number on the engine. It should be either HUFM-21C or HUFM-21S.

Sorry for the long post but if anyone has any advice to offer I would appreciate it. Let me know if there's something that I've overlooked. I'd like to get ahead of it so I have the parts needed on hand when I actually have time to work on it.

Thanks in advance,
Chris
 
Thanks for the quick reply Bondo. Here are some larger pictures. I didn't know if I should keep file sizes small for hosting reasons or not. In the parts diagram here I see an anchor and other connecting linkage but I'm not sure what I'm missing or how exactly it connects.

I could probably get a new reconditioned carb for around $250 and then start from scratch with the linkage but I'm not sure what all I need.

IMG_0365 (1).jpg
IMG_0367.jpg
 
Ayuh,..... I don't do OMCs,.... But,....

That cable looks more like an Outboard cable end, 'n not an I/O carb connection,....
Atleast nothin' like the Merc or Volvo connections I've seen,....
 
A DualJet was created in the early/mid 80's to try to satisfy the EPA...as far as I know of, it was never used in a marine application - I think you would be Very WISE to find a viable replacement (2GV).

From what I can see, somebody 'rigged' the dualjet's auto linkage to work with the marine control cable....the appropriate 2GV carb should come with a stud that should match the cable's end fitting.
 
Mark makes some good points re; the carburetor and cable attachment. If you are going to bring this boat back to life, use all Marine components!


Also, please note that the Buick V6 (of that vintage) was an "odd fire" engine. This means that the degree division between crankshaft position and cylinder valve operation is NOT equal! The ignition distributor's cam and the distributor cap must be indexed correctly, or serious engine damage will result!
This has ZERO to do with firing order....... it has everything to do with the degree of separation between the actual firing of each cylinder!


If you are curious, you can read post #3 on this Off-Road dot com forum. (I cannot verify the accuracy of the information)
http://forums.off-road.com/jeepster-american-jeepster-club/60875-odd-fire-what.html

Also, Marine Engine ignition advance curves are specific for Marine use. in other words, DO NOT use the automotive ignition advance curve data for your Marine Engine!


Have fun and good luck!



.
 
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