Fast Fred's OMC Mod 50 secrets Thread #2

[tumblweed9999]

Thanks Tim!!! quick reply
thanks for the rev warning. Yeah the engine runs a bit better now. Since i discovered the #2 coil ground wire was sparking off the side off the block! Doh! I just bought the engine this summer and it ran great, then developed a miss. Apparently whoever put it back to gether missed that in reassembly, yet it somehow stayed stuck and grounded until a couple weeks ago. The plugs seem wetter than my 65. all the time. Somethings probably up.

Hey Tumbleweed,

The OMC triple carbs come in three venturi sizes 1.125", 1.187", and 1.250". Smaller venturi's will get you stronger bottom end, larger venturi's get you better top end. These carbs all share a 2.375" bolt pattern and may be interchanged at will.

Whatever carb changes you make, you shouldn't EVER quick rev and engine! Spitback can be controlled with velocity my stacks ($175/set includes fasteners and shipping).

Best for you to do some lake testing. Just be sure to monitor plug reads frequently until you get it sorted out.

Tim

[velocity85]

Hi guys

Can be either you tell me more about the engines Johnson 60 -65 - 70 -75
I want to work well where I own 65 and I have a boat F4 ss and I watched the subject completely, but please media in detail because I live in a country far I know these secrets speed but who can help me on private or respond explanation and pictures

thank you

[Fast Fred]

the 65 is an older motor, it has no boost port. is it electric shift? you can make a 75hp out of a 70hp. the black box, you want the one with no limiter.

[velocity85]

I have now Yamaha 85 hp engine 0.4 with compressed work Portenq and expanded openings in the Block with light work Head 1 mm Vicenq not try so far, but I like Johnson engines very much want to learn more

[velocity85]

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[Fast Fred]

the 3cyl Yamaha is vary similar to the 3cyl Johnson. what shaft length is your 85hp, over hear they only come in L and i think XL transom height.
your pics did not go through i don't think

[velocity85]

it's 20 shaft length

[velocity85]

[Fast Fred]

seems got enuff parts parts to put a Stinger 75 together, or three, so i'll build one.

[velocity85]

Yes Can you you let me know I want to know the pressure glaze PSTN Johnson engine 70 - 75 hp if Standard and if Bustn size 50