Fast Fred's OMC Mod 50 secrets Thread #2

[Xpress2830]

Laker I didn't see your reply

[Lil' Blue Rude]

Hey guys I am new here. Been looking at some of your mods to the triples. I have a 93 Johnson 40 J40EETB stock. Fresh top end 0.020 over new rods pistons etc... I put 50 carbs with 49D mains & 31 & 29 air, 50 reed stops with CCMS fiberglass reeds. No performance increase. My uncle has a 1990 48 stock on the same boat and he smokes my tail. He's turnin a 11 3/4 x 17 at 6000 RPM with boat loaded two people. Motor will turn 6500 but he stays out of it. I have same setup only turnin 5800 and I am not on the rev limiter. Any ideas would be appreciated. Thanks, Bobby... my # 337-764-5534 if you have time to talk...

Been a while since I messed with the jetting on my 2 cylinder but seems like 49 mains seem pretty small for 50hp carbs seems like the 50's I had used 54 mains stock. Might just be a different model but have you checked the plugs to see what they look like?

[Xpress2830]

Hey Rude thanks for the reply. I have another set of carbs off a 1990 48 with 55D mains & 56 low speed jets. These carbs are not the all metal body they have the plastic top. Gonna run when weather gets better. I read alot about this motor and I am wondering if the exhaust port timing is different on the 48 & 50. If so I may reun better with the stock 40 carbs & reed stops. Hey give me a call if you get time. Bobby @ 337-764-5534. Thanks

[Fast Fred]

wow almost 200,000

[tborisch]

Hi Guys, new to the site, but not to boating!

Tim, I think the engine your showing on page 61 is probably the engine I have now? I purchased it from Mick Nolan. I run the boat in Northern Michigan now. Amazing Power!

Attachment 60929

Thanks!
Tom

[Tim Kurcz]

Yep, that one's one of only three built with enclosed exhaust for harassment-free laking. Enjoy!

Tim

[Fast Fred]

lookin like a merc bracket on there, i need a bracket similar

[tborisch]

lookin like a merc bracket on there, i need a bracket similar

Yup, it is.

[Steves Jem]

920cc with the Mod 50 straight front. A lot of guys here in AU in the 90's ran similar power heads with a great deal of success. I had one on the stock SST60 mid section and nitro gear box. The difference between the stock SST60 and this engine was 1,000 rpm. Ran a kilo averaged 88mph on my Mono and got a one way speed of over 90mph. Had great fun outrunning the F3 tunnels with quick foots to the first buoy and did beat a few of the slower F3 boats.

Stephen Medaris

[smixon14]

Just out of curiosity... what would i be searching for if i wanted to use the 4 over 4 or 5 over 5 reed block front half on a 56ci? Converting my motor to EFI via microsquirt and im not racing so im not tied to any rules or regs.