ONE PING! then the shakes

GoldenMotor.com
Nov 23, 2009
189
3
18
Lakeland, FL
This one is for all you deep technical types. I was out riding the Andian after installing a new Manic Mechanic hub and 40T sprocket (love it by the way) and I was going up a long, slightly steep hill. I was in some traffic so I was trying to keep the speed up to limit my exposure to the chrome bumpers going by. I gave it a little more gas and heard one "ping!" (like a tap, a tooth jump, but not so violent or something like that) and the engine vibrated a little more. I let up and the shake went away. The engine seemed a little down on power but I made it home.

When I checked over the engine, I noticed that the spark plug was out about 7-8 threads. Yup, it was backed out enough that I could see the threads. My first thought was that the theads stripped and the plug backed out but, when I tightened it back up, it went back in and sealed okay. I checked everything out and took it back out for a ride. It seems to have more power (obviously this is reasonable since the plug was loose but, it seems to vibrate more when I give it gas. Now, full disclosure, I've recently put in different fuel with a lot more oil in it. I'm thinking that may be contributing to the increased vibration also because I noted that it ran smoother when I reduced the oil. I typically run about 32:1 but, I ran out and my friend had 8oz. of oil so we rode up to the gas pump, put in all the oil and found out that my 2 gal. tank only holds about just over a gallon. I figure its like breaking in the engine again. :D

I hear that these cranks are 2-3 peices, and I'm wondering if possibly it might have twisted or shifted and therefore, out of balance? There is no different noise than normal under any driving situation. Maybe I'm thinking too much.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,272
1,810
113
Los Angeles, CA.
Too much oil will definatly cause your engine to run rough.
Also, check your drive chain & rear sprocket... the chain shaking can also cause vibrations.
 
Nov 23, 2009
189
3
18
Lakeland, FL
One step ahead of you Venice. I just tightened it up tonight and did a few adjustments back there. I'm running out of things that I want to "fix" on this bike so maybe I'm just looking for other things. I'll probably put some different fuel in the tank soon, or, I'll just dilute it a little and see how it does. I was starting to be amazed at how well it was running on the lower oil content fuel. The higher oil content is probably making it run that way. I really like the way the bike runs, when it isn't struggling through an excessive, internal oil slick. :D

I also figured that if the plug threads were indeed stripped out, it would be a good time to replace them with a heli-coil and sand down the head a little bit. That'll help it run a little better too, I'd think.

I have a friend who is sending me a MIG jet fighter helmet and I'm thinking about my next build. I want to make a MIG fighter jet theme bike. He even found me a Russian D8 engine kit over there! I'm throwing it around. But, I've got to figure out what "style" I would use to build it.

thanks for the info and support guys!