Beginning on second gallon of break-in gas. The engine just began cutting out then quit. I rewired the kill switch thinking I was robbing the magneto, on the "white" wire. It didn't seem to help. I also moved the c-clip up on the throttle valve.. I am getting frustated. can anybody diagose? the problem> THANKS
erratic running of engine
- Thread starter geronimo
- Start date
Vistaman73
Member
what ratio you running? check your plug, if its black, gooey, than your too rich. if its white or gray, then your too lean, you want a dark tan, chocolate color. 32:1 is what i run. make sure everything is on right and check to see if your idle speed is correct. do all that and then check back. BTW: vids always help. 
Are you using the factory electrical connectors?
They are notoriously horrible.
You are better off soldering the connections or using balun spade connectors.
Here's a picture of a female connector as sold at O'Riley auto parts:
http://www.oreillyauto.com/site/c/d...yword=electrical+connector&pt=N0214&ppt=C0189
And here's a male connector:
http://www.oreillyauto.com/site/c/d...yword=electrical+connector&pt=N0214&ppt=C0189
Most all auto parts stores sell them in the electrical section fairly cheap.
I recommend crimping and soldering them on, and using heat shrink tubing to insulate them.
http://www.oreillyauto.com/site/c/detail/DOR4/85283.oap?keyword=heat+shrink+sleeve!s!tubing
They are notoriously horrible.
You are better off soldering the connections or using balun spade connectors.
Here's a picture of a female connector as sold at O'Riley auto parts:
http://www.oreillyauto.com/site/c/d...yword=electrical+connector&pt=N0214&ppt=C0189
And here's a male connector:
http://www.oreillyauto.com/site/c/d...yword=electrical+connector&pt=N0214&ppt=C0189
Most all auto parts stores sell them in the electrical section fairly cheap.
I recommend crimping and soldering them on, and using heat shrink tubing to insulate them.
http://www.oreillyauto.com/site/c/detail/DOR4/85283.oap?keyword=heat+shrink+sleeve!s!tubing
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AussieSteve
Active Member
what ratio you running? check your plug, if its black, gooey, than your too rich. if its white or gray, then your too lean, you want a dark tan, chocolate color. 32:1 is what i run. make sure everything is on right and check to see if your idle speed is correct. do all that and then check back. BTW: vids always help.
Vistaman73, the terms 'rich' and 'lean' do not refer to the fuel/oil ratio. They refer to the fuel/air mixture. It's very confusing when you use those terms for the fuel/oil ratio.
Secondly, you don't vary the amount of oil to achieve the correct plug colour. This is bad advice.
If the plug is black, the fuel/air mixture is too rich. If the plug is white or grey, it's too lean. The plug should be light tan. For low to mid-throttle openings, the slide needle controls the mixture. At WOT, the main jet comes into play.
Further, setting the idle screw correctly will have no bearing on this problem.
geronimo, as Gearnut says, double-check all electrical connections and make especially sure that nothing is shorting to ground.
Sometimes the HT lead can be a bit loose in the CDI and plug boot. Ensure that it's screwed well into both.
Have you tried a new spark plug? If not, do so. An NGK B6HS works best.
Also, check that you're getting adequate fuel flow from the tank. Do you have an inline filter?
If I were you I'd also pull the carb apart and give it a clean.
Vistaman73
Member
Aussie, your right. My post was a little confusing. I was jumping around giving advice on what COULD be the problem.
1. What's your ratio? Again, 32:1 is a good one
2. Check the plug for a tan, chocolate color. Black is too rich. White/grey is too lean.
Use the clip in the carb to adjust for that, I can't remember right off the top which way is richer/leaner. Sorry.
3.And since the description was not the most detailed, I just threw the idle speed in there. It never hurts to check Aussie. Make sure its still there and set right.
4. Check the fuel lines and carb/petcock for blocks. Clean the carb and install a fuel filter.
5. Check connections and get a new plug, or even get a new cdi/connections.
6. If you can, check the magento to make sure it is working right.
There, that is what I was trying to say, and I added a little bit. Aussie, thanks for stepping up and telling me, I'm glad you did. It's nice to get a respectful post back to me for once. Hope this all works out geronimo.
1. What's your ratio? Again, 32:1 is a good one
2. Check the plug for a tan, chocolate color. Black is too rich. White/grey is too lean.
Use the clip in the carb to adjust for that, I can't remember right off the top which way is richer/leaner. Sorry.
3.And since the description was not the most detailed, I just threw the idle speed in there. It never hurts to check Aussie.
Make sure its still there and set right.4. Check the fuel lines and carb/petcock for blocks. Clean the carb and install a fuel filter.
5. Check connections and get a new plug, or even get a new cdi/connections.
6. If you can, check the magento to make sure it is working right.
There, that is what I was trying to say, and I added a little bit. Aussie, thanks for stepping up and telling me, I'm glad you did. It's nice to get a respectful post back to me for once.
Hope this all works out geronimo.
AussieSteve
Active Member
Vistaman73, I'm glad that you didn't take personal offense - none was intended.
To enrich the mixture for low to mid throttle openings, the slide needle needs to be raised, allowing more fuel into the mixture. ie The clip must be lowered.
And vice versa.
For full throttle, the main jet size comes into play. A larger main jet will enrich the mixture and a smaller one will make it leaner.
There's a bit more info here:- NT Carb Tuning Basics
Incidentally, I ran mine in with a 16:1 fuel/oil ratio, then changed to 20:1, which I still use today. If the carb is correctly tuned, there's no build-up on the plug and it's a nice tan colour. (There's a pic of my plug colour in the NT Carb Tuning thread.)
With these engines, due to poor manufacturing tolerances, the more oil you can get away with, the better. It helps the piston rings seal against the cylinder wall, ensuring maximum compression.
To enrich the mixture for low to mid throttle openings, the slide needle needs to be raised, allowing more fuel into the mixture. ie The clip must be lowered.
And vice versa.
For full throttle, the main jet size comes into play. A larger main jet will enrich the mixture and a smaller one will make it leaner.
There's a bit more info here:- NT Carb Tuning Basics
Incidentally, I ran mine in with a 16:1 fuel/oil ratio, then changed to 20:1, which I still use today. If the carb is correctly tuned, there's no build-up on the plug and it's a nice tan colour. (There's a pic of my plug colour in the NT Carb Tuning thread.)
With these engines, due to poor manufacturing tolerances, the more oil you can get away with, the better. It helps the piston rings seal against the cylinder wall, ensuring maximum compression.
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