Topic: 18HP Opposed Twin Performance Upgrade Path

[AZCOWBOY]

Thanks will do...

[BIG AL 202]

Rooster,
Do you know if this link is still good to get a hold of Tim?
I called the # on the site and it just keep ringing...
Thanks

HE HAS SEVERAL DIFFERENT GRINDS FOR THE OPPY'S. TELL HIM WHAT YOU GOT AND WHAT AND HOW YOU INTEND TO USE IT, AND HE CAN HELP!

[AZCOWBOY]

I have the 42 oppy talked to Rooster once and he said to ask for the Rooster grind..

Thanks

[BIG AL 202]

I have the 42 oppy talked to Rooster once and he said to ask for the Rooster grind..

Thanks

YOU MAY STILL WANT TO TALK TO TIM BECAUSE WHAT YOU ARE DOING AND WHAT ROOSTER HAS DONE TO HIS COULD BE 2 DIFFERENT GRINDS! JON WILL BE THE FIRST TO SAY "TIM KNOWS MORE ABOUT CAMS THAN THE REST OF US PUT TOGETHER" LOL

[Rooster]

YOU MAY STILL WANT TO TALK TO TIM BECAUSE WHAT YOU ARE DOING AND WHAT ROOSTER HAS DONE TO HIS COULD BE 2 DIFFERENT GRINDS! JON WILL BE THE FIRST TO SAY "TIM KNOWS MORE ABOUT CAMS THAN THE REST OF US PUT TOGETHER" LOL

Eggzactly!

[Scott P.]

Well I finally finished up my mower. However I have an issue. Even with it at WOT, it will not go past 2800 RPM. Even completely unloaded.

Here is what all I did with the motor:
-All of Don's oiling mods
-Clean up and smoothing of intake and exhaust ports
-ARC aluminum flywheel
-PCV ports in the block
-Fuel pump pulse port to the intake manifold
-Governor delete
-Dual 1.5" exhaust

The pistons, rods, and cam are all stock.

What could be the issue?

As far as I can see the carb is not adjustable aside from the idle fuel mixture and idle set screw. Also I have not messed with the timing on the flywheel, it currently is in the full negative position, any recommendations on this for a mostly otherwise stock motor?

[BIG AL 202]

IGNITION TIMING, OR LACK OF FUEL, CHECK THE COLOR OF THE PLUGS. TO CHECK THE PLUGS, RUN IT TO THE RPM YOU WANT TO CHECK, HOLD IT THERE FOR A MOMENT [10-15 SEC] AND SHUT IT OFF, HOLDING IT AT THE RPM. YOU WILL BE ABLE TO CHECK IT AT THAT RPM. THAT SHOULD TELL YOU WHAT IT IS.

[Jim Knutson]

also put all the shroud tins back on it before you cook the engine.

[BIG AL 202]

also put all the shroud tins back on it before you cook the engine.

[Jim Knutson]

it also appears that you may have blocked off the stock bowl vent location with the air filter adapter you have. you need to externally vent the bowl, that may be the issue....seen it before. also, remove choke, and plug the holes left by the choke shaft. you will have to fatten the low end a bit to compensate for the choke removal, for easier starts.

[George Herrin]

YUP USING THAT FILTER ADAPTER REQUIRES THE BOWL TO BE EXTERNALLY VENTED

[Scott P.]

That picture was taken right after I finished assembling the motor.

I am using the stock air cleaner box and air filter because I would have to heavily modify that adapter to make it work.

All of the sheet metal also went back on when I put the motor on the tractor.

YUP USING THAT FILTER ADAPTER REQUIRES THE BOWL TO BE EXTERNALLY VENTED

[flatlanderfornow]

1.5" is too big for the exhaust on a basically stock engine- 1" od pipes would be better. 

[Scott P.]

Well today I added 4 degrees of timing and I also plumbed in a newer style plastic Briggs fuel pump and it seemed to run a little better except after running for about 5 minutes it shut down and then didn't want to crank over until it was completely cooled. The starter was getting super hot and not able to crank it over like it was locking up for some reason. I don't know what the heck is going on.

[BIG AL 202]

BETTER CHECK THE CONNECTIONS ON THE BATTERY AND ARE YOU USING THE RIGHT SIZE CABLE? IS THE STARTER NEWER OR OLD? DID IT DO THIS BEFORE YOU ADVANCED THE TIMING? SORRY FOR ALL THE QUESTIONS BUT WE DON'T WANT TO BLINDLY JUST GUESS.