Hodaka wombat 94a plug keeps fouling

[scarman]

This keeps happening on a fresh rebuild, Im running 40:1 premix but I keep fouling the plug after about 1 hhour ride time. I take the bike for short
rides and after about the 3rd or 4th ride , the plug starts missing and then she wont run. Swap the plug..everything is fine. Am I getting not
enought spark so I need a new coil.(rebuilt the old one). The compression is about 120..is that too low? Im using the stock B8HS plug.
Is there a hotter plug that I can use? Carb has stock settings and I am around sea level 60-70 degrees (Southern Cal) . Any ideas or thoughts appreciated.
Im a newb so looking for the easy fix first. Thanks

[Dale]

It runs fine otherwise?
No excessive smoke?
It is possible that your condenser is failing when heated up. In the time it takes to change the plug, it can cool off and run again for a time. Have you tried just letting it cool off and then starting it again without changing the plug? If it will do that, then the condenser is suspect.

[scarman]

Ive swapped out old plugs that fouled after it cooled and they dont work...only a fresh plug will do..Can I use a hotter plug and what would that be?

[Dale]

To answer your question about what a hotter plug would be, it would be a B7HS. However that is not the route I would take without trying to figure out the source of the fouled plugs first. You may have already stated it in your rebuilt coil. I am still wondering how it runs when it is running?

Does it run rich?
How does it idle?
How are your points adjusted?
Was an air leakdown test performed after the rebuild?

Dale

[Bullfrog]

Please describe the color of the insulator nose on one of fouled plugs. Changing to a hotter plug is not recommended. Something else is wrong.

[Darrell]

Possibly the right-hand crank seal is passing transmission oil into the crankcase.

As for the compression reading 120 psi is a bit low for a newly rebuilt engine. I would try another tester to confirm the first one is calibrated right.

[hodakamax]

A long shot, but an opening in the air filtration system can cause plugs to "whisker" after a short running time. It's sometimes hard to see. Just another possibility.

Max

[Bullfrog]

A good description of plug color - or better yet - a good, well focused photo would be very helpful. Especially of a plug seconds after being removed (no time for other junk to contaminate what we see).
Ed

[MTRob]

Same thing kept haping to me.I checked everything found noting. I finally cut down on the permix gas to 20:1 and my plug fouling ended.
To much oil in the gas...........
MTRob

[bchappy]

Bel-Ray MC-1 Synthetic Oil solved my plug fouling problem back in 1970 and I still use it today in all my Hodakas. You may have some other problem that needs to be fixed but a synthetic oil will not foul as fast as petroleum or castor based oils.
Just my 2 cents.

[viclioce]

First running tor premix at 40:1 is probably part of your lower compression problem. Your not getting enough oil to the piston rings to get a better seal. Drop your premix to 32:1 and try it again. This will also make you run a bit leaner as well, and could possibly be a reason your running a bit rich at that mix ratio.

I had a similar problem. It was a dirty carb and the carb was too rich. I had to clean the carb AND Install a smaller pilot jet. The PO was running a 40 pilot jet in a carb which called for a 35 pilot as stock. The idle circuit was too rich, so rich in fact that the bike would start cold without engaging the choke. When the bike warmed up it would then flood and foul the plug.

Three questions. What pilot jet and main jet do you have and is it the stock carb? Do you know what size pilot jet is in it and is it the stock size for that carb and motor? Do you start the bike cold with the choke engaged or not? Let us know! ; D Victor

[Bill2001]

And also make sure that the float is adjusted perfectly and gives the correct fuel level. I don't know if there is a separate spec for the level of the fuel in the float bowl but of the float is "waterlogged" with gasoline and gives a higher fuel level even with a higher float adjustment it will run richer. Check the throttle slide needle-- if it is mis-adjusted and set in a different notch that will affect the mixture. Look closely for wear in the needle-- in-use it can vibrate against the _needle jet_ and wear a shoulder into the needle. And also, replace the needle jet on rebuild-- years of having the needle vibrate against the jet can wollow-out the needle jet, and make it larger and richer. On some slide-valve carbs there is an "atomizer" or "emulsifier" at the top of the main jet carrier that functions as a air-correction jet. If that atomizer is dirty and the holes blocked the mixture will run rich with less correction air being passed.

--Bill

[scarman]

Sorry it took so long to get back..Thanks for all the tips..I will rebuild the carb and put all stock parts in to make sure they are correct. I wasnt sure what the needle jet and the main are.