85hp V4 Mod begins

[spybot]

Thanks again gents
This is all taken on board. I will measure piston as described once i have the motor split.
Are the burn marks on top of the head any think to be worried about ??
It seem it had detonation on only the onside of the cylinder ???

[spybot]

No I don't Frank ..... Maybe racervboat will chime in as I'm sure he has them and if he doesn't soon I will contact him.
Gary

Hi Gary any joy on the port numbers ?

[olboatman]

Hi Gary any joy on the port numbers ?

Sorry forgot.....will text Ken today.
Gary

[spybot]

Thanks Gary
Just trying to get all the info i need gathered up.
The port sizes are one of the most important but one of the last things i need (Info Wise)
Will post a few pics of the heads and intake later on.
Something strange been happening on the port side pots.
Maybe someone can tell me what has caused the difference.

[olboatman]

OK according to my guru if the 85 is the large bore (3.5") the ports should be simular to the 140s. Add the bubble back, hi comp heads, larger intake, reeds and carbs and ya should be close to a 140. You could square off the ports ( I usually do since it is open) and add a little timing. You will see an improvement!!! Don't forget most of the mph improvement will be in the setup and prop.

Gary

[FMP]

And if is a small, find a large ? I was waiting for the numbers, just to see how it's timed for comparison.

[olboatman]

I understand Frank but Ken doesnt have them and I looked around but can't seem to find them. Maybe I should start a thread to ask?
Gary

[FMP]

Just for kicks. I had the KR 15 #s somewhere or whatever someone made them.

[spybot]

OK according to my guru if the 85 is the large bore (3.5") the ports should be simular to the 140s. Add the bubble back, hi comp heads, larger intake, reeds and carbs and ya should be close to a 140. You could square off the ports ( I usually do since it is open) and add a little timing. You will see an improvement!!! Don't forget most of the mph improvement will be in the setup and prop.

Gary

You have lost me on the "larger intake" Do you mean by smoothing out the bumps and casting marks ?
also when you say add a little timing Do you mean advance or retard the timing ?
Sorry if the above are dumb questions
Thanks again for the info, mine is the large bore model.
Hopefully get the intake and reed cages done this week, will post the pics of my progress.
I will start a new thread on the size of the ports once i can get a map done.
Andy

[FMP]

Search online Two Stroke Tuners Handbook, read it you'll like it.
Port timing, height of ports in degrees of crank rotation, duration open .

[olboatman]

Andy go to the thread I started (Port timing #s for an OMC 140) this morning and read what racervboat posted. I ment adding a couple Deg of timing and if I am correct the 140 front case has larger carb holes and flows better (someone correct if I am wrong Please). Notice that racervboat said run the stock tuner. He raced these motas for a few yrs and did very well...he built the mota I have for my Viper (a clone of his race motas) and his work is top notch!
Gary

[71V153]

Think the V4 intake manifolds are purty much the same regardless of HP. Later ones were an inch taller and incorporated fuel recirc lines. Shift linkage was updated too.

[71V153]

Look on top of of #2 cyinder. Just fwd of the head. Does it say 11 or 9?

Tells ya everything ya need to know far as current port timing.

[FMP]

Well, how much info can two #1s side by side tell us?

[71V153]

That the block is ported to 115/140 specs?