Fouling Plugs

[MattyQ]

Hi ,
I have a friend who is having trouble with his 6B motor.  The bike will run for a minute , then foul a plug over and over again.  Any  help for him would be appreciated .

Thanks !

Matthew Quinlan

[Ernie Phillips]

Dump the fuel tank & clean the carb.   Mix up a batch of fresh gas/oil.  (I use Yamahalube 32:1)  Install correct new plug (NGK B8HS is one).  Clean the air filter and properly service it.  Check timing.  Got good compression?

Go to open riding area, crank it up, and nail it.  Run it wide open, if Ok then it may just be a carb jetting issue.  If not it may be ignition related - bad motoplats act strange.  Good luck!



Ernie P.
Chattanooga, TN

[wfopete]

I have had this symptom/problem from time to time, most recently at the ISDTRR.  I believe my issue was excess fuel in the crankcase.  My bike had been sitting for a couple of months without draining the fuel or any other fuel system maintenance.  The bike would start but anytime a load was put on it, it would load up and stall.  After pulling the carb and checking the ignition (and changing several spark plugs) I got the Jackpiner's engine to get good and warm, actually pull a gear and "clean the gunk out of the crankcase".  After that; no more problems.  I have yet prove or disprove that fuel floods the crankcase, it's just my theory. Might be a float hieght or float needle issue.  For all I know, the carb maybe letting excess fuel in from boucing up and down just traveling down the road on a trailer.

Pete Petrick
Penton Jackpiner
Slow but Good

[MattyQ]

As always thanks for all the great info and friendly advise!

Matthew Quinlan

[chicagojerry]

i had similar problems with a 250 the weekend of the evansville C-C. it turned out that the needle jet was worn on one side. not that easy to spot without taking it out of the carb. put in a good one and viola, bike starts runing good. good luck.   chi jer

[MattyQ]

I noticed a lot of folks run Yamalube in their vintage bikes .  Is that a good non synthetic oil that is good for vintage bikes?

Matthew Quinlan

[wfopete]

I'm running Maxima 927 Castrol for that "vintage" fragrance that stays with you mile after mile.

Splash a little on; you'll love it!

Pete Petrick
Penton Jackpiner
Slow but Good


'01 KTM EXC 520, '74 YZ 250, '86 Honda XR 250, '71 Hodaka 100, '74 SUZUKI TM 400, '73 Penton Jackpiner

[Speedy]

quote:Originally posted by MattyQ

Hi ,
I have a friend who is having trouble with his 6B motor.  The bike will run for a minute , then foul a plug over and over again.  Any  help for him would be appreciated .

Thanks !

Matthew Quinlan

For all you EXHAUST smokers.
Get some OPTI oil,..mix it 100-1 and you will never have a problem with your sparkplugs anymore.
//www.opti2-4.com
Ask Opti for a dealer near you and do it.

Helmut"Speedy"Clasen
 Ontario Canada
http://speedy_c.tripod.com
http://picasaweb.google.com/vindurospeedy
2 x Sachs MC-GS 250-7A
1 x Hercules 350-7A 77
2 x Hercules 250-7A 76
2 x Hercules 250-7A 77
Zuendapp 125 GS 72-73

[Speedy]

quote:Originally posted by Speedy

quote:Originally posted by MattyQ

Hi ,
I have a friend who is having trouble with his 6B motor.  The bike will run for a minute , then foul a plug over and over again.  Any  help for him would be appreciated .

Thanks !

Matthew Quinlan

For all you EXHAUST smokers.
Get some OPTI oil,..mix it 100-1 and you will never have a problem with your sparkplugs anymore.
//www.opti2-4.com
Ask Opti for a dealer near you and do it.

Helmut"Speedy"Clasen
 Ontario Canada
http://speedy_c.tripod.com
http://picasaweb.google.com/vindurospeedy
2 x Sachs MC-GS 250-7A
1 x Hercules 350-7A 77
2 x Hercules 250-7A 76
2 x Hercules 250-7A 77
Zuendapp 125 GS 72-73

Helmut"Speedy"Clasen
 Ontario Canada
http://speedy_c.tripod.com
http://picasaweb.google.com/vindurospeedy
2 x Sachs MC-GS 250-7A
1 x Hercules 350-7A 77
2 x Hercules 250-7A 76
2 x Hercules 250-7A 77
Zuendapp 125 GS 72-73

[Big Mac]

Excess fuel or "flooding" into the crankcase, as WFOPete points out, will cause this symptom. Usually, it will start and blubber at closed throttle, but die as soon as you open it up at all. Sometimes it won't start at all, with plug showing nice blue spark and coming out wet w/ fuel. A 250 Harescrambler I had did this if I left the fuel taps on while parked for an hour+, as the floats weren't closing the needle valve off all the way and carb was overflowing a tiny bit down through the intake. Didn't cause the plug to foul, but plugs will wet-foul at times.

If you're not aware, the KTM motors (like CZ motors) have an allen head screw up between the fins, right below the crank, just for the purpose of draining excess fuel. Just a teaspoon-full of excess will cause it--once drained, my 250 would start first kick, run perfect. Not sure if the Sachs have a drain screw...if not, turning off fuel and laying it over on the side will sometimes clean it out sufficiently. I'd try this easy fix first.


Jon McLean
Lake Grove, OR

[MattyQ]

Thanks for all the info !  I guess I shouldn't be running Morris 2 stroke oil at 20 :1 !  I read that on the following repair site , that said to be safe run at 20:1 because you never really know the proper ratio to run for all these oils out there !

Here is what was written by Dan's Motor Cycle Repair

http://www.dansmc.com/indexindex.htm

I'll condense hours and hours of study and research to one statement. "You can run the manufactures oil at whatever ratio the manufacture says and feel safe. ANY other oil run at 20 to 1."(20 parts gas to 1 part oil) .In other words run Honda oil in Honda 2/strokes at Honda ratios. But if you run Honda oil in a Yamaha, run it at 20/1. Yamaha oil in a Honda? Same thing 20/1. They all say "Ours is the finest oil available." Trouble is they will not really tell you why.



FOLLOW THE ABOVE RULE

If You Don't.... It's OK.... I Don't Care.... It's Not My Engine!!!!

Now, I know a lot of you out there who feel you can run things much leaner. Like 32 to 1 or 40 to 1 or even leaner. No less an expert than Bob Greene recommended a 32 to 1 mix and no less an expert than Gordon Jennings recommended a 20 to 1 mix. A lot of people run lean and a lot of them get away with it... and a lot of them don't. So what gives ? I feel the problem is this. No one really knows at what dilution the 2-stroke oils are mixed at or exactly what additives are added. At least I don't, and I've tried to find out a number of times. They send you a bunch of specs but will only say "Ours is the finest available." They never say why their $3.00 a quart oil is better then the $5.00 a quart stuff. Here are a few ideas to consider.

Let's look at dilution. At least that's my word for it, and I don't really mean the weight of the oil either. Most say they are a 30w. I mean the ratio of the stuff that counts to the stuff they put in to make it look and mix good. That make sense ? Probably not ! Well, think of it this way. If oil "A" is twice as thick as oil "B" and you mix both at 40 to 1, oil "A" will really be 20 to 1, right ? Now think about the reverse. If "A" is half as thick as oil "B" and you mix both at 40 to 1. "A" would now be 80 to 1. A bit lean right ? I don't think the real dilution ratios, between different oils, are that big. I do think there is enough of a difference between 2-stroke oils to cause a problem. Especially when you consider the additive package.

Gas to Oil Pre-Mix Ratios
for Two Stroke Engines



USA Mixtures
Ounces of Oil to Gallons of Gas

Ratio
Gas to Oil 1 Gallon
Gas 2 Gallons
Gas 3 Gallons
Gas 4 Gallons
Gas 5 Gallons
Gas
16 to 1 8 Oz
Oil 16 Oz
Oil 24 Oz
Oil 32 Oz
Oil 40 Oz
Oil
20 to 1
BEST 6.4 Oz
Oil 12.8 Oz
Oil 19.2 Oz
Oil 25.6 Oz
Oil 32 Oz
Oil
32 to 1
OK 4 Oz
Oil 8 Oz
Oil 12 Oz
Oil 16 Oz
Oil 20 Oz
Oil
40 to 1
NOT SO GOOD 3.2 Oz
Oil 6.4 Oz
Oil 9.6 Oz
Oil 12.8 Oz
Oil 16 Oz
Oil
50 to 1
DO NOT USE 2.56 Oz
Oil 5.12 Oz
Oil 7.68 Oz
Oil 10.24 Oz
Oil 12.8 Oz
Oil
100 to 1
NEVER USE ! 1.28 Oz
Oil 2.56 Oz
Oil 3.84 Oz
Oil 5.12 Oz
Oil 6.4 Oz
Oil



Matthew Quinlan

[tofriedel]

Matty,

Just about everything Dan believes about 2-stroke oil mixture goes against what all dirt bike manufacturers recommend for the gas to oil ratio.  This also applies to smaller industrial 2-stroke engines.

For over 40 years on numerous brands of 2-stroke MC's and under varying elevations, temperature, rider ability and event (MX, CC, Enduro, Hare Scramble, dirt track, road race, etc.) I never ran more than 32-1 ratio and NEVER did I seize an engine due to the fuel ratio.  I have seized a few because of improper jetting on long high speed events, but never at MX, Enduro, CC, etc.  

I will continue to run at 32 or 40 to 1.  I am even going to experiment with Speedy's recommendation on an Enduro bike, Penton SD.

We all have our bias when it comes to many things about MC's, timing, oil, spark plug, chain, filter, etc. and we usually go with what has worked successfully for us over the years.

I do agree with the following statement -

If You Don't.... It's OK.... I Don't Care.... It's Not My Engine!!!!

Just my take, no offense meant to anyone's own experience.

Tony

[MattyQ]

Tony ,

Appreciate your thoughts, I figured 20:1 was too rich.  I like to hear everyones point of view and passion! Having a two stroke enduro , I  worry about not varying my speed enough on the road and causing seizure!  

Matty

[TGTech]

MattyQ,
Too much oil can cause plug fouling, but there is one other thing, that you ought to pay very close attention to.

First off, we used the Hi Point concentrate oil for the entire age of the Penton era, and while that product is no longer branded, Hi Point, it is still out there on the market. It's called Golden Spectro and it is exactly the same product. You mix it at 52:1 (12 oz. in 5 gallons) and if the jetting is proper and the air is clean (properly cleaned and serviced air filter), then the oil will not be an issue.

The other thing that you need to to make sure is, that the ignition is working properly. All of the mounting of the ignition components need to be sure that there is no rust or corrosion between the parts. AND there can't be rust or corrosion between the engine and frame.

Make sure that the spark plug cap, is mounted cleanly to the spark plug wire. If the cap has been installed for a long time, it is a good thing, to remove it, trim back the wire a little bit, and reinstall it. That way you know, that there is no corrosion between the wire and the cap.

Make sure that the stator terminals connecting to the coil, are clean and free of corrosion. Over time, they can develop some corrosion, and that can cause issues with the ignition system.

Lastly, if the ignition spark is not bright blue or "whitish blue", then you may have issues with the ignition itself. If the magnetism of the flywheel has weakened, that can cause a lower voltage output to the coil. We can remagnetize them at the shop.

If you want to send the system to us, we can do the whole dynamic test of the system, including the remagnetizing of the flywheel. The cost is $34 plus shipping charges.

Dane

[Dennis Jones]

WHAT DANE SAID Been there, Done all the above, A new PVL made every thing good.
Golden Spectro 52:1 is all that I've used for 30 years in all my 2 strokes. Bikes, Lawn Mowers, Chain Saw, Weed Eater, Leaf Blower, Ect

Dennis Jones