Bike Has Spark, Won’t Start

MiffedFan

Member
Nov 8, 2021
51
1
8
46
I checked for fuel at the plug before and it has the odor or fuel which dissipated after a few moments. It was not wet with fuel though. Should it be wet or just have the odor of fuel?
 

curtisfox

Well-Known Member
Dec 29, 2008
5,549
2,491
113
minesota
Disconnect it from the carb and make sure you have a nice steady flow, if not take the gas cap off then check again...........Curt
 

MiffedFan

Member
Nov 8, 2021
51
1
8
46
Ok, fuel is now at 32:1. We have good fuel flow, fuel bowl fills. Still no ignition. Let’s assume we have an airflow problem here. A photo is attached showing the whole bikes setup. If there is an airflow problem preventing fuel and air from getting to the spark plug, what can be done to address that beyond what has already been done? I have cranked the engine cold and then checked the plug, there is an odor of fuel, but the plug is not wet with gas moisture. Any suggestions here?
 

Attachments

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,827
764
113
Los Angeles, CA.
Ok, fuel is now at 32:1. We have good fuel flow, fuel bowl fills. Still no ignition. Let’s assume we have an airflow problem here. A photo is attached showing the whole bikes setup. If there is an airflow problem preventing fuel and air from getting to the spark plug, what can be done to address that beyond what has already been done? I have cranked the engine cold and then checked the plug, there is an odor of fuel, but the plug is not wet with gas moisture. Any suggestions here?

I'm looking at the picture... Put that choke lever DOWN or the bike will never start!!!
 

MiffedFan

Member
Nov 8, 2021
51
1
8
46
We have tried both ways. Most recent test was putting a few drops of gas under the spark plug. No go.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,827
764
113
Los Angeles, CA.
We have tried both ways. Most recent test was putting a few drops of gas under the spark plug. No go.

There's a 'sweet spot' with the choke lever that the engine will fire up almost instantly... It's usually about 2/3 of the way up.

If the choke is 100% of the way up, it will only flood.



Ride the bike going down a long hill... pop the clutch, & hold the throttle wide open... & then reach over with the left hand & slowly move the choke up & down (in the mid range).

You should hear the engine popping & coming to life!
 

wrench

Well-Known Member
Aug 20, 2019
366
337
63
So Cal
I checked for fuel at the plug before and it has the odor or fuel which dissipated after a few moments. It was not wet with fuel though. Should it be wet or just have the odor of fuel?
You've mentioned a few times your not sure if your getting fuel in the cyl
Leave the S/P out and turn over the engine. Hold your hand in front of the S/P hole. You'll see and feel the fuel air mist come out of the S/P hole and get all over your hand.
Now you can eliminate the possibility of no fuel as a problem
 

MiffedFan

Member
Nov 8, 2021
51
1
8
46
Tried the above just now. Definite compression, definite fuel smell on finger after plugging the spark plug hole. Not wet, but odor of gas. Will try the choke adjustments tomorrow. A bit dark and cold at this point.
 

MiffedFan

Member
Nov 8, 2021
51
1
8
46
Just tried to run the bike with several small adjustments to the choke. Ran the bike for a good long time with each adjustment. The bike still will not attempt to start. I’m really at a loss here. I’m not aware of anything else that could be done. Still hoping someone else has the key.
 

MiffedFan

Member
Nov 8, 2021
51
1
8
46
The muffler is new. So I am pretty certain there is no clogs or anything. What would prevent the engine from getting fuel from the carb? The carb itself? Mechanical failure in the carb? Any suggestions here would be helpful. I do have another carb I can put back on.
 

curtisfox

Well-Known Member
Dec 29, 2008
5,549
2,491
113
minesota
We have tried both ways. Most recent test was putting a few drops of gas under the spark plug. No go.
few drops of gas under the spark plug, probably not enough, don't be afraid, to much will just dry up, most of the time it will start just takes a while longer......Curt
 

Greg58

Well-Known Member
May 1, 2011
4,621
1,391
113
63
Newnan,Georgia U.S.A.
Ok back to basics, is the engine turning over real strong when you release the clutch? It should cycle just like it does with the plug out. Try taking off the mag cover and watch the magnet turn as your son tries to start it, just to make sure the clutch is doing its job. I’m not questioning you but it’s going to be something minor.