[tony zambos]

Rod,
The bottom line is that motor probaby needs to go into a shop. A worn ring, piston, cylinder or all of the above. Assuming you have the same type plug in each engine. You try a new plug, properly gapped, and see if that helps.

[Rod Hawkins]

[quote quote=71443]Rod,
The bottom line is that motor probaby needs to go into a shop. A worn ring, piston, cylinder or all of the above. Assuming you have the same type plug in each engine. You try a new plug, properly gapped, and see if that helps.

[/quote]

Tony, thanks for the quick reply. Problem is that it has done this since I had a new top end done. So thats why I was thinking maybe it might be something else, carb? Plug? etc…

It very well could be that it wasn’t rebuilt properly, which I hope is not the case, since it has done this since the rebuild and since it is my back up motor, that rebuild was done over a year ago, and probably hard to take it back to the builder and say he did it wrong. I did see him at the last race and asked him about it and he attributed it to my newbie buddy not driving it hard, but as I look back at it, I realize it has been this way with me driving as well, but it was so long ago, I just forgot.

[Walt Gifford]

Maybe it’s just running real rich? What are your carb settings?

Could be the ignition is too far back.

Gif

[tony zambos]

Certainly take Walt’s advice. Try swapping the carbs between motors. And I’ve that engine builders are human. Work with him.

[Rod Hawkins]

Just noticed that my high needle was almost 1/4 turn out and low was about 2 1/4. I guess I need to close it to 1/8 or less and run it.

[Matt Dixon]

Walt is on point. Sounds to rich. Make very small adjustments the high, bigger on the low.

I used to tune to the color of the header, a nice tan color. White to lean black to rich.

[Rod Hawkins]

for the KPV is there a “standard” setting for these needles (at a certain temp and elevation) or is every motor a little different and you just have to play with it to get it perfect?

Sorry for the dumb questions.

TIA

[Anonymous]

Depending on what exhaust you’re using, it could be slightly different, but we ran them with the 2, 3, and 4 pipes and the settings we usually ran on the carb were between 2 and 2.5 on the low at speed, and about 1/8 on the high. Usually you have to have the low around 1-1.5 at start up to get it to pull off the grid without bogging down, and once the RPMS start to come up as you leave the grid, open it to 2-2.5.

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