What NGK plug?

[Jeffrey Hammond]

What is the correct NGK spark plug for a Zenoah 260 PUM stock motor?

 

[the german]

Jeff
It is the NGK CMR7H.

Alex

 

[Kristy Wallace]

NGK iridium

 

[Kristy Wallace]

Would like to try the brisk variety , but long thread

 

[Jeffrey Hammond]

Kristy
Have you tried the iridium plugs? Do they make a noticeable
Difference?

 

[Wally Duarte]

Kristy
Have you tried the iridium plugs? Do they make a noticeable
Difference?

JB , seen them make a difference in a modified engine. Doubt you’d see anything out of a stock engine

 

[Kristy Wallace]

Kristy
Have you tried the iridium plugs? Do they make a noticeable
Difference?

Yes ,but more importantly they are more reliable

 

[Jeffrey Hammond]

I ordered 6 NGK CMR7H plugs. That should last me a good long time.
Thanks for all of the input

 

[the german]

Don't forget the squeeze them down to a .018 gap .

Alex

 

[Alan Elzer]

Don't forget the squeeze them down to a .018 gap .

Alex

Whats that help with from stock gap ?

 

[Jeffrey Hammond]

The German
Yup, I have the same question.

 

[Roxyflash]

Kristy
Have you tried the iridium plugs? Do they make a noticeable
Difference?

There tall like a normal spark plug and expensive

 

[Rich Jones]

I ordered 6 NGK CMR7H plugs. That should last me a good long time.
Thanks for all of the input

That’s the plug I run in all my motors, modified or stock. I don’t have experience with the Iridium but the standard CMR7H last a long time. The plugs and fuel is where you save an absolute TON compared to Nitro and the learning curve is WAY easier. If your boat didn’t start at the lake, it’s because of one of less than a handful reasons. If it’s a stock Zen, with a 257 carb, open your low 2 1/8 and high 1 1/8. Put your thumb over the carb opening and pull a time or two. You should have gas on your thumb. Then start pulling with radio in hand. Sometimes you have to open the throttle some. It helps to have someone to hold the boat for you. Make your you can close the carb to shut the motor off. Make sure your bolts are tight and gaskets are in place. You can do this in the garage or on the patio. Don’t worry about letting the motor idle and revving it a few times. You don’t need to run water through it for that small amount of run time. Then you can drain the gas and start the motor one more time and hold throttle open until motor quits to run the gas out of the carb. Then store for the winter. That is if you want, you can wait til spring too.

 

[the german]

Take a CMR7H out of the package you'll measure around .025. This gap can lead to misfire at higher RPM's. Bring the gap down to .018 it will cure it.
Even I made me a squeezer to gap it.

Alex

 

[the german]

That’s the plug I run in all my motors, modified or stock. I don’t have experience with the Iridium but the standard CMR7H last a long time. The plugs and fuel is where you save an absolute TON compared to Nitro and the learning curve is WAY easier. If your boat didn’t start at the lake, it’s because of one of less than a handful reasons. If it’s a stock Zen, with a 257 carb, open your low 2 1/8 and high 1 1/8. Put your thumb over the carb opening and pull a time or two. You should have gas on your thumb. Then start pulling with radio in hand. Sometimes you have to open the throttle some. It helps to have someone to hold the boat for you. Make your you can close the carb to shut the motor off. Make sure your bolts are tight and gaskets are in place. You can do this in the garage or on the patio. Don’t worry about letting the motor idle and revving it a few times. You don’t need to run water through it for that small amount of run time. Then you can drain the gas and start the motor one more time and hold throttle open until motor quits to run the gas out of the carb. Then store for the winter. That is if you want, you can wait til spring too.

I always leave the rest of the gas in the carb. You don't want the diaphragm seal to dry out. Never had any issue .
Just my opinion.

Alex