Mercury in line 6 hop ups

[Mark75H]

It is the deflector piston design that is the major limiter. The "Direct Charge" was a 10hp+ improvement over conventional deflector.

[Dave S]

says who......

[Tom Smyth]

supercharge a la the verado......

[Tom Smyth]

It is the deflector piston design that is the major limiter. The "Direct Charge" was a 10hp+ improvement over conventional deflector.

f you look the 1250 BP was a deflector motor rated at 125 crank horsepower and 99 cubic inches. The 1250 Super BP was the same displacement but a direct charge piston design and rated at about 140 HP ( ish ) . no other real modifications were made to the SBP motor, so one can assume the direct charge design DID offer a significant HP improvement( 10-15%) . Exhaust chest was the same size, carbs were ALMOST identical......not much else different......and the 1250 SBP turned into the production 135 HP motor... still about a 10% increase from the 1250 BP.

[86vintage]

I have enjoyed building a number of inlines. An old school racer told me the transfer cover with the ramp into the transfer wasn't needed he said all the fast guys would just machine up a flat aluminum plate and bolt that on. Is that True?? Mark 75H over the years I have read a lot of misinformation you wonder some times what works and what doesn't. I have been building 2 stroke motorcycles engines for over 45 years. I always go conservative and work up slowly, because it is real disappointing when you over build an engine and it falls on it's face unless completely wide open throttle WFO lol

[Mark75H]

I have enjoyed building a number of inlines. An old school racer told me the transfer cover with the ramp into the transfer wasn't needed he said all the fast guys would just machine up a flat aluminum plate and bolt that on. Is that True?? Mark 75H over the years I have read a lot of misinformation you wonder some times what works and what doesn't. I have been building 2 stroke motorcycles engines for over 45 years. I always go conservative and work up slowly, because it is real disappointing when you over build an engine and it falls on it's face unless completely wide open throttle WFO lol

Its complete BS. I have never seen this on any Merc made after 1952. If it worked, all the factory team motors would have had it.

You may add whoever told you that to the list of people to ignore. Its sad that there are so many people out there willing to make stuff up like this. You never know which end of them the stuff is coming from.

[86vintage]

Thanks for the reply. Actually the fellow that said that to me was an old boat collector I used to work with. So no worries we will not have to ignore him he doesn't come to this site.
I switched to 200hp 2.5 v6's 10 years ago and never looked back. I do have a couple of inlines left I need to build and sell one of which is a 1500xs bored .015 with Vertex high domes. I left all the ports as is and only lightly cleaned up the casting flaws.
Thanx again,
Jamie

[FMP]

Jamie
Check the threads last couple days, someone is looking to buy a 1500 inline. How does it run?

[86vintage]

actually I stated I have a couple of inlines left I need to build.
After I get my boat finished, I hope to get to building the inlines and sell them. I will hang on to the XS that my find a happy home on a 1971 Sidewinder.

[FMP]

Ah, I thought two to build, plus one ready.