wilsonreef

I have a OPS 90 marine engine. It has the needle on the carb, and a remote needle. Does anyone know a good starting point on setting these needles?

Thanks,
Carl

Hydro Junkie

If you're going to use the remote needle, the carb needle needs to be wide open but not to the point that it leaks. As for the remote, I'd start at 3.5 turns out and adjust as needed from there

c.k.y.

Hi wilsonreef


I use CMB old type Push-pull type carb

wilsonreef

Thanks guys...

Carl

wilsonreef

I've got to ask, why the need for the two needles?

Carl

Hydro Junkie

The remote needle was an aftermarket add on and probably isn't really needed UNLESS you want to be able to fine tune the mix while you're on the water. In that case, the carb's integral needle isn't really needed. I know I had the integral needle removed from the carbs of two NR 21s partially for that reason as well as lack of room for them in the boat

wilsonreef

Yeah, I tried running it without the remote needle, it just flooded the carb, to the point it was throwing nitro out of the exhaust. I thought I had the needle out only about 1.5 turns. I could be wrong. This was about a year ago, and I bought a RCMK to go into my Aeromarine SC. Hydro, If I bypass the remote needle where should I start with the carb needle. Don't really want to use the remote if I don't have to..

Thanks,
Carl

chief3452

Hey Carl,

If you could post some pictures of your two needle setup it would be helpful. The information HJ provided is a good ballpark. Depending on your altitude, 3.5 to 4 turns is probably a safe needle setting to START your engine. Now, RUNNING it there for an extended period of time is another issue altogether. If you haven't already, I recommend joining International Waters, post pictures and ask your question there. You will have access to some of the best information on OPS engines on the web. Not a slam on RCU, just a good group of experienced nitro guys who are familiar with the old OPS engines.

Good Luck.

wilsonreef

On another note, does anyone have a good starting dimension from the center of the glo plug to the convergence point on the pipe?  If using a 2" band pipe, is the convergence point the middle of the band or is it where the first taper hits the band?

Thanks,
Carl

f16man

Glow plug center to end of first taper.....length should be something between 13'' to 14'' / always cut long
on the header and shorten to the sweet spot.

da357mag

I; m the new kid on the block(56) but I had a OPS 45 in the 80s and I found the needle was good about 2and1/4th open. Don't know about the .90, but from what I remember they all liked that setting. I didn't use a remote nedel at that time since there was no need for it. Just a thought! while I'm here is there a good place to get outrigger plans? tried the web but couldn't fine what I was looking for! Best...Doug

advanced builder

If the engine is highly modified it MAY need to take in more fuel, My .67 Picco ,the needle was almost falling out ,running.I could not get enough fuel in. So I re-drilled the fuel fitting hole ,one size over the fitting hole. I also re-drilled the spray bar hole. Now my needle is working OK When you open up the liner ports that's more fuel/air volume. Depending on how modified. Be very careful. I did have extra carbs. in case I messed up. The needle on the carb is a idle needle without seeing it.

wilsonreef

wilsonreef

Tom Moorehouse ( http://www.intlwaters.com. His are called the firefighter riggers he has plans for several different sizes. I have the 90 size. really like it.

Carl