Rich or Lean?

[Almighty Crap]

I just built this bike not too long ago. I wanna know if my spark plug shows me if its too lean or rich. My fuel is 40 to 1 ratio and I'm aware you can move the clip on the carb to make it run more rich or Lean. It was middle on default and I moved it down to the more richer side. I drove it around for a good 5 min to see the result I get. And I'm not sure what the spark plug is indicating because I'm kind of new to this stuff. Also my bike can only top out about 20 or 18 mph. I don't know if it's my exhaust pipe robbing all the power or it's the carb needle. Please help and I would be happy for answers!

 

[DAMIEN1307]

I drove it around for a good 5 min to see the result I get.......I'm not sure what the spark plug is indicating because I'm kind of new to this stuff

5 minutes was just about long enough to just get it warmed up, but not long enough to even begin checking the spark plug just yet.

Your spark plug is not indicating anything as you have not ridden it far enough or long enough.

Try that one again but give it at least a half hour this time.

As far as top end speed is concerned, I have never seen it where those poo poo exhuast pipes do any good whatsoever in that department, you would actually get more top end with the stock pipe...A smaller rear sprocket will also help out for better speed but its a trade off as you won't have as much low end torque.

Also, is that an after market head or the one that came with the engine kit???

Change your fuel mixture as well to 25 to one mix ratio for the breakin period which is about 100 miles or so which means about two tankfuls of gas and mix your gas and oil in a gas can, not just in the tank as it will not be consistantly mixed that way...It has to be done in a gallon gas can and shaken vigorously in order to mix it properly and then pour it into the tank, and be sure to be using Conventional oil only during break-in period...NO synthetics until after break-in.

If your using the Chinese spark plugs that come with these things, throw it out, they are garbage as well...Most of us here change them out immediately to an NGK-BR6HS spark plug gapped at .025 thousandths.

I never even checked my plug until the first 300 miles or so once everything was fully broken in as well as running a couple tanks after that and this is what my plug looked like which is about the best perfect burn your gonna get.

 

[weefek]

40:1 is not good for these engines, ESPECIALLY during break-in. If your build is 'new', I'm assuming it's a new engine. You should be running 25:1 or so like @DAMIEN1307 said. I played it safe and ran more like 20:1 or something during break in but that doesn't matter (I forget to be honest but it was something like that). During break in, the oil mix should be heavier. I also took it apart and cleaned out the excess carbon after break-in.

After break-in is done 32:1 seems to be the favorite ratio. 40:1 is weedwhacker area, not MB area. The torque requirements are quite different. I run 30:1 as a rule and have no issues (AFTER break-in).

Are you sure about the 40:1? Your plug shows rich for sure. Which isn't necessarily a bad thing during break-in. Depends on your elevation, @DAMIEN1307 is the expert on that.

Don't even bother tuning or anything for performance before break-in is done (approx 2 gas tanks full, for me about 200km or so but it depends). The engine acts and reacts completely different after the break-in period.

It would help to know what engine kit you have, what fuel you are running, etc. I assume from the pics you're not running the stock plug but if you are throw that thing in the garbage and get a proper NGK plug

 

[DAMIEN1307]

This is my Phantom 85 in pics below...Everything on it is stock as it came out of the box with the exception of the air filter...I am using the 36 tooth sprocket because the motor itself has plenty of low end torque allowing me to just go from a dead stop without any pedaling if I wish and easily hits 51 MPH...I am still running only a 20:1 oil/fuel mix long even after my breakin period but on a more conventional motor like yours, 32:1 after breakin is fine with full synthetic oil if you wish at that point.

 

[GW's Motorized]

Sweet bike. Damien, I was going to post the same two pics when I read the title.

 

[DAMIEN1307]

Are you sure about the 40:1? Your plug shows rich for sure. Which isn't necessarily a bad thing during break-in. Depends on your elevation, @DAMIEN1307 is the expert on that.

He only ran it for 5 minutes, no where near long enough on the Chinese "Z" plug, or any plug for that matter, to even begin to be a credible reading for rich or not just yet.

 

[weefek]

True enough. But it's very black. I would expect that with a more oil to gas mix or a super rich mix. Weird that it looks like that with 40:1. Maybe he measured wrong.

Stop showing off your bike we've all seen it and know that it's t*ts, Hayzeus Christo.

 

[weefek]

Also to be fair, all the chinese plugs I've dealt with personally were the triple type , doesn't look like a chinese plug to me, although I may be wrong

 

[GW's Motorized]

Also to be fair, all the chinese plugs I've dealt with personally were the triple type , doesn't look like a chinese plug to me, although I may be wrong

The plug that was in my kit looked the same as that. It had the code and no name other than "spark plug" stamped in the metal

 

[DAMIEN1307]

Stop showing off your bike we've all seen it and know that it's t*ts

It ain't there for you folks, it is there for our new forum member to show him it's still stock with a stock ,out of the box, exhaust as well...lol...lol.