Looking for OMC service bulletin #1144 and/or #1429

[Keyboardman]

I'm rebuilding the carbs on my 1976 75hp Stinger and would like to do the Mods needed to help out the acceleration problem that seems to be inherent on these certain models. Google didn't bring up much more than links back to this forum discussing it. I've read that Mr. Joe Reeves may have them. I don't know how to find him here on the forum. Any help is appreciated. Thanks!

 

[boobie]

Send him a PM.

 

[Joe Reeves]

That bulletin you speak of for the 1976 3 cylinder models may not be needed for the 75hp model if it has run normally in the past.. The hesitation could also me caused by a Sticking Timer Base, having the Throttle Butterflies Opening Too Soon In Relation To The Idle Timing, or Fouled Carburetors.

However, If you still want that bulletin, PM me your email address an I'll get it to you.

 

[Keyboardman]

After more searching I was finally able to find the SB #1429 which says it's for models 1976 70 and 75 hp. The timer base on my engine seems to move freely and advances before the throttle does. I'm sure the carbs need a rebuild as it's sat for a while. I figured I would do the mods while I had them apart. Now, I do have a set of carbs from a '78 Evinrude which has the bigger low speed (.032) jets in them. Maybe I should rebuild and use them instead of modding the old ones on the '76?

 

[Joe Reeves]

************************************* Error - Misquote - Sorrry

 

[Keyboardman]

So, just rebuild the original carbs without the modifications? I'd hate to do the rebuild and still have the same problem.

 

[Joe Reeves]

I just re-read the bulletin.... strange that in all my years the only horsepower that needed modification was the 70hp model... and somehow I had completely forgotten that it involved all of the three cylinder models which of course includes the 75hp model... and the bulletin clearly states that. My apologies for overlooking that fact which clearly causes me to rethink my statement. Got to be a age thing!

Yes, by all means, modify the carburetors as per the bulletin. Again... My apologies for the goof!

 

[Keyboardman]

Thank you Mr Reeves for the clarification. While I'm waiting for the kits to come in, I thought I'd check the low speed jets that are in the carbs already. I pulled one out of the top carb and discovered that it's a #33. So, somebody has already been messing around with them. When I do disassemble them I will check with the corresponding size drill bits to see if they have enlarged the holes in the HS nozzle and the LS calibration ports.

 

[Joe Reeves]

Thank you Mr Reeves for the clarification. While I'm waiting for the kits to come in, I thought I'd check the low speed jets that are in the carbs already. I pulled one out of the top carb and discovered that it's a #33. So, somebody has already been messing around with them. When I do disassemble them I will check with the corresponding size drill bits to see if they have enlarged the holes in the HS nozzle and the LS calibration ports.

1976 75hp Evinrude/Johnson - Good idea to double check the jet sizes.

Both jets are fuel flow jets.

S/S - 317473 - ,030 ID - Marked on face 30
H/S - 318684 - .056 ID - Marked on side 56D

Unlikely the H/S nozzle has been enlarged, at least I've never heard of that happening. Apparently over the years, the top cylinder encountered a lean condition for that .033 S/S jet to be installed, however three (3) sizes is quite a jump.

 

[Keyboardman]

I received the rebuild kits yesterday but I'm unable to find the #55,56,57 drill bits needed for the mods here in my local stores. I'll have to order them online. Uggh!

 

[Keyboardman]

After inspecting the old carbs, I found excessive play in the carb bodies where the throttle plate shafts go thru. I checked out the carb set from a 78 Evinrude 75hp I had laying around and they were much tighter. I checked the HS nozzle hole sizes and the ones in the LS calibration chamber and they matched the sizes in the Service Bulletin. So, I rebuilt them with the correct .032 jets and installed on engine. The engine Idles great and will throttle up while in gear on muffs. My test tank is way too small to put it in gear and keep any water in it. I'll take her down to the ramp and give it a test in the real world! Hopefully my problems are solved. Thanks all for the help.

 

[Joe Reeves]

Good catch on the throttle shaft play... that will raise cain with the fuel/air mixture, lousy idle, etc.

 

[Keyboardman]

I've read that a temporary fix would be to pack some thick grease around the shafts but, with the amount of play I had I didn't think that would work too well. My only other thought was to bore and sleeve the carb body with some brass tubing but that seemed like a lot of trouble. Probably the only way to save those old carb bodies though.

 

[racerone]

You may find that most of the wear is on the brass shaft , not the aluminum bore of carburetor.

 

[Keyboardman]

It's a Steel shaft going thru aluminum carb body. Had same problem in Ford transmission where the steel servo rod went thru aluminum case and wore it out. Only way to repair it was to bore and sleeve.