Not often but every great now and then I can kill the engine and it will diesel.
Anyone have a remedy?

 

Using 93 octane fixed that on mine.

 

I have been using pure gas at 90 octane and premium with a shot of startron. I was wondering if I might have carbon build up causing hot spots. Thought Id try the old trick of getting the engine up to operating temp and then spraying cold water into the carb to break up carbon deposits..??

 

the shelf on the heads combustion chamber has hot spots and the mix screw is probly rich

and if you are north of 9.5 to 1 this is going to happen -- better fuel can and does help as was said above

 

stop using gas additive its not going to help and adding water will cause lots of drama in an air cooled engine

 

Thanks John, I have 10.1 and have been running too rich for a while now. I just reduced main jet dn to a 72 today so ought to be running a little leaner now. Running damn good now for sure.

 

Startron is just to neutralize the ethanol, so stop using startron? Why would it make dieseling?

 

I just pulled my front plug, here is the pictures. One side is tan and the other side is darker.? Looks to have the right shade of tan.

 

You can't read plugs anymore with this ethanol crap... my bike has the PERFECT amount of decel pop, no surging on decel, no coughing or spitting once warmed up, no pinging, but the front insulator only shows one spot with a little tan on it... no black spots or ***** of aluminum.


My bike is running stock compression, but if it's really hot after a good run, it will diesel. Out of 10 shutdowns, it will do it 2/10 times... I'm not really worried about it. I've run 93, 89... it seems that it didn't start doing it until I put in 89, but at stock compression, with a v-thunder 3010, it shouldn't need 91/93 octane.

 

You have just a tad too much timing, heat mark should be in the center of the bend, may be promoting your dieseling also.