CMB .67

[jeff baham]

GUYS I HAVE THE PURPLE HEAD .67 IN MY TWIN , SO I START TO RUN THE ENGINES ON LAND AND ONE WILL STAY RUNNING AND THE OTHE WILL RUN THEN STOP , I CHANGED THE GLOW PLUG TO A NEW ONE AND IT DID THE SAME START UP , RUN A FEW SECOND THEN DIE, RAISED THE THROTTLE UP A LITTLE MORE START UP A FEW SECONDS THE DIE, COULD IT BE THAT THE PISTON /SLEEVE FIT IS TO TIGHT.

 

[Ray Sametz]

Look elsewhere, it can never be to tight.

 

[Neil LaGarry]

I had to change brand of glow plugs ,same reason was using odonnel blue

 

[SayMikey]

Make sure your pipe fitting is not plugged up just remove the hose at pressure fitting and see if it will stay running. Got a flow meter? Flow both needles and see if junk is in your carb

 

[jeff baham]

ill try again ,will reclean the fuel filter and carb needle. no I don't have a flow meter.

 

[bermudadude]

back plate could b leaking

 

[MXNERD]

ill try again ,will reclean the fuel filter and carb needle. no I don't have a flow meter.

Jeff get yourself a flow meter as I will make life a lot more enjoyable with a twin

 

[jeff baham]

ok, ran the twins yesterday , and the only thing I can see was that they were to rich , because the motor that would start and die , stayed running when I leaned it a few clicks, then the other motor started do the same thing , start then die, so I leaned it a few clicks so now they both are running , then on my third tanks my last belt broke .so got some comeing from otto.

MXNERD

where can I find a flow meter and what do they cost.

 

[jeff baham]

ok thanks greg

 

[John Beardslee]

Hi Jeff,

You can always go old school until you get a flow meter and use a stop watch and a fuel bulb. We used the smaller fuel bulb and would put it on the fuel line to the needle and then squeeze it in one hand and hold it and punch the stop watch and release the bulb at the same time. We would stop the time when the bulb stopped expanding. The longer the bulb took to expand the leaner the needle was. We would match engines this way or set one richer or leaner depending on what your plug readings tell you.

Thanks, John

 

[jeff baham]

john yes I forgot about that method, I saw brent hatfield do that years ago when I started raceing in 89 ,plus is the fuel bulb one of those bugger getters for babies back in the days

 

[John Beardslee]

Hi Jeff,

No we used a regular model plane/car/boat fuel bulb. They were a dark reddish orange color. I still have one, it fits nicely in the palm of your hand. I just bought the larger size from Tower, they still carry the original size.

Thanks, John

 

[jeff baham]

ok thanks