Is my engine too rich or too lean? (pics + vid)

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My engine four strokes at max speed and im trying to fix it and increase performance. First time taking out spark plug after several hundred miles (see images). Im told brown is ideal which appears to be the case. Ive taken off the air filter for maximum airflow (I dont notice a difference in performance or four stroking). I have not modified the carb and I installed it default (im not sure what # jet is used). Im open to changing the jet # to increase performance. The exhaust pipe end fell off and currently has a tin can which still appears to allow better airflow then the stock end cap.

Video:

This is my kit: https://www.ebay.com/itm/383920220520

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1. Do you think my engine has too little gas or too much gas? Or does it have too little air or too much air?
2. How does the spark plug color look?
3. Whats the default jet #? Would # jet would you recommend? How do I know if its compatabile with my carb? (im buying on ebay)
4. Any other suggestions to increase performance and/or four stroking?
 
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I would say you are actually a tad on the rich side, and you may want to go with a hotter plug as well.

I am not sure what your stock jet size is, somebody else may be able to chime in on that one.
I know nothing about spark plugs, is there a brand / model or specification I should get? What would a hotter spark plug do? Does this mean it creates a larger spark during every revolution or something?
 

Greg58

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The most common cure for the wide open four stroking is a smaller jet, if you go to a smaller jet lower the clip on the needle so it’s not too lean at less than full throttle.
 

Risk Man

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Risk Man safety suggestion: If you care about your feet (they are pretty important and I can attest to that having had over a dozen surgeries on both of my feet and ankles) you might want to refrain from wearing flip flops on a motor bike. I know this is not an answer for your problem but as the Risk Man, I can not resist the comment. thanks

Dennis
 

ImpulseRocket89

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I know nothing about spark plugs, is there a brand / model or specification I should get? What would a hotter spark plug do? Does this mean it creates a larger spark during every revolution or something?
Spark plugs come with a heat range rating. In simple terms it is the electrode size/shape that is changed on a model of spark plug to shed heat and operate at a given temperature. The "hotter" the plug, the slower it sheds combustion heat, but the better it is at self cleaning as the engine runs. Too cold and the plug doesn't self clean and will be more prone to fouling. Too hot and there can be a risk of it causing pre-ignition.

I will use NGK as the basis of this comparison since it is easiest to remember. The standard spark plug for most of these 2 stroke engines is an NGK B8HS. The number in the plug code is the heat range, and with NGK plugs, the higher the number, the colder the plug. So if you wanted to go with a "hotter" plug, you would want to lower that number. Many people seem to like running a B5HS or B6HS with good luck. Since these engines really don't run very hot, or have aggressive ignition timing, they can run a hotter plug without issue.
 

Chainlube

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My engine four strokes at max speed and im trying to fix it and increase performance. First time taking out spark plug after several hundred miles (see images). Im told brown is ideal which appears to be the case. Ive taken off the air filter for maximum airflow (I dont notice a difference in performance or four stroking). I have not modified the carb and I installed it default (im not sure what # jet is used). Im open to changing the jet # to increase performance. The exhaust pipe end fell off and currently has a tin can which still appears to allow better airflow then the stock end cap.

Video:

This is my kit: https://www.ebay.com/itm/383920220520

View attachment 177976


View attachment 177977


1. Do you think my engine has too little gas or too much gas? Or does it have too little air or too much air?
2. How does the spark plug color look?
3. Whats the default jet #? Would # jet would you recommend? How do I know if its compatabile with my carb? (im buying on ebay)
4. Any other suggestions to increase performance and/or four stroking?

That all looks fine, get a NGK B6HS spark plug gapped at .025. And use the air filter, dust is a big destroyer of engines.
 
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