Facts about Evinrude/Johnson racing outboards made my OMC

[lars strom]

Powerful Bass-boat.
1985 Evinrude 300XP V8 looper

[lars strom]

Apparently there never was an over heating problem.
The engine's internal water-flow-passages kept the electrical wiring from shorting/melting.

Correct..never a over heating problem.

[WaterZebra]

Correct..never a over heating problem.

Did any OMC engine product ever use surface gap plugs? It sounds like surface gap plug production may be ending?

[lars strom]

Did any OMC engine product ever use surface gap plugs? It sounds like surface gap plug production may be ending?

Absolutely..lots of OMC models used this one as an example.
Champion L78V but you can use a regular spark plug.

[lars strom]

This is by far the most common Champion Spark Plug for OMC models.
L77JC4

[Rotary John]

[QUOTE=lars strom;3359843]Absolutely..lots of OMC models used this one as an example.
Champion L78V but you can use a regular spark plug.

[/QUO]The rotary snow mobile and race engine used a surface gap plug exclusively. It was made 12mm to prevent the conventional J gap plug from being used as it would have destroyed the engine.

[lars strom]

The rotary snow mobile and race engine used a surface gap plug exclusively. It was made 12mm to prevent the conventional J gap plug from being used as it would have destroyed the engine...

WOW..I did not know that.

Thanks Rotary John.

[keith scotton]

1985 and earlier crossflow V6 where required to use UL77V plugs. I have seen the top of the piston melted away with the use of gap plugs on 235 - 200 HP motors.

[Amberjack1234]

1985 and earlier crossflow V6 where required to use UL77V plugs. I have seen the top of the piston melted away with the use of gap plugs on 235 - 200 HP motors.

Even though I was a Johnson dealer back in the day I never had a clear understanding of the V-8 motor since we did not sell any at that time. I would like to know the difference if someone can explain to me between the 250 The 275 and the 300 and 300 GT. Just wondering as I only sold the Four cylinders and early six cylinders in crossflow

[BLisBack!]

I think the only liter sizes were 3.6 and 4.0. Most the time they just varied the carb size (like on other engines), The 300 had the biggest carbs (plastic venturi body and throttle plates are bigger). I just picked up a 3.6/300 and it had the big carbs. Sold the carbs on ebay for $700. I don't mess with the carbs or OMC electronics anymore, EFI is the way to go. Not sure what the diff was between the 300 and the 300 GT.

-BL

[lars strom]

Johnson Stinger 75HP
OMC advertising.

Great engine.

[WaterZebra]

I always thought the "disappearing pixel" graphics on the Stinger should have been used on the F1 V8 engine cowls.

[keith scotton]

Was told best spark plug for carbureted F1 V8 was a Champion LG 505

[John Schubert]

Was told best spark plug for carbureted F1 V8 was a Champion LG 505

Also the same spark plug we used in the Quincy Loopers in the late 60's early 70's. Platinum wire core.

[lars strom]

Powerful Bass-boat.
1985 Evinrude 300XP V8 looper

Another very cool..really fast powerful Bass-boat.
This Champion is also powered by a 1985 Evinrude V8 XP 300HP.