Bike running poorly. Just did the Quenton Upgrade

[80's old school]

I am going to ask the forum instead of bothering Quenton, I am sure he has his handsfull after this storm!!

I recently aquired a bike with a NE5 engine. The bike idled great, but would sputter if ran above about 1/3rd throttle. It also did not have much power.

I took the engine apart and found the lifters destroyed!!!

I quickly called Quenton and he came to the rescue!!! I got his upgraded mushroom lifters, he milled the head, and cleaned up the combustion chamber, he also reworked the cylinder and replaced the valve springs.

I put everything back together with the cam advanced one tooth.

It fired right back up and idles fine. Now when I take off, it has almost zero power down low and sputters horribly until you get to about 25 mph and then it comes alive like an animal and screams!!!!!

After just running her a couple of times up and down the street, the plug is turning black.

Any ideas???

 

[Brent Merkley]

I had a similar problem and it turned out that the cam gear was rotated on the cam shaft. It was caused by a set of mushroom lifters from Taiwan, the mushroom part of the lifter was too tall which caused the lifters and cam jam against the inside of the case. Its was hard to figure out. I changed to a different cam to solve the problem.My symptoms were exactly the same as yours.
Best of luck

 

[80's old school]

Well it turns out to be pig rich!! I did a little "chemical jetting"!!! By that I mean I mixed up a concoction of about 75% E-85 and 25% gasoline and it runs perfect!!

Since it takes much more E-85 to run right, this basically did the same as jetting the carb down.

I may play with it a little and see how she does at 100% E-85. I think I will have to raise the needle a little and maybe idle her up since I feel the idle jetting will be too small.