You should see this thing after we come back from riding. We tend to ride on dry lake beds so that I can get out and drive too. It is almost white when we get back. The silt washes off easy though (with manual labor from my wife and daughter ) and that is why it stays looking so clean.

We finally are updating this. We broke in the Engine and are now working on jetting it. We are at 4500 elevation and with the 47cc coolhead dome we have a compression of 161 psi. We have the stock needle setting and stock pilot jet in the stock carb with a 135 main jet as suggested by the book for the altitude and temp of our area. We used the 90 settings because we have the 90 silencer on this pilot. The only other mods to this pilot is a 3" tube out of the airbox with an airaid prefilter and a uni in the airbox and a CR250r 4 petal read cage & stuffer with the boysen 2 stage reeds. We also had the stock 7 heat range plug in it for our first plug chop.
From the pics it looks like the plug is too hot and it is running a little lean. I want to move to an 8 heat range plug. I would like your thoughts on if I should change the main jet now before another plug chop or if I should just leave it and check it with the colder plug first.

From the pics it looks like the plug is too hot and it is running a little lean. I want to move to an 8 heat range plug. I would like your thoughts on if I should change the main jet now before another plug chop or if I should just leave it and check it with the colder plug first.

Why do you want to change the heat range, what heat range are you running what have you been running in the past?

If your going to cut the plug apart to read it I would suggest you buy some of the less expensive standard plugs and save the fine wire plug for after the jetting Make sure your not getting fake plugs viewtopic.php?f=1&t=118

Not much color on the plug how is the Engine running if its not screaming and showing any signs of being too lean I would run it longer then read the plug and check for the heat range.

viewtopic.php?t=870

List all your mods and current jetting.

As previously posted these are the mods. Do you not think that the plug looks like it is too hot Hoser?

Do you have a side view pic of the ground electrode all I see is the back side .



I would have started with a 142 main jet and middle groove for the clip.

These are the pictures that you asked for.

I would have started with a 142 main jet and middle groove for the clip.
We started with a 7 heat range plug with a 138 jet and it seemed too rich. See pics.

The 7 heat range plug with a 138 jet looks fat in the pics but how does it compare in run time to the second plug that is almost white, was their a bunch of idle and low speed time on the dark plug that the light plug did not see?

Their is a blond area on this plug so you can see the smoke ring width.



The taper reach on the plug makes it hard to read in pictures you can really see how far back the heat was.

Yes there was some idle time on the 138 and it was ridden for 18 minutes of riding vs the couple minutes on the 135. We are going to switch to a 136 main and do a plug chop with regular ngk plug in both a 7 and 8 heat range. This should not have a taper so you can see the burn better in pics. we will not be able to do this until next weekend so we will post again after that. Thanks Hoser for looking at this. With my eyesight as bad as it is my wife is trying to help with this and she is not sure about what she is seeing.

Have the wife look at this see if it helps her any, If she knew why it might help her more?

We will retry a 138 instead next weekend with both plug temps. If that doesn't work we will play with the needle clip next.

These are the plug chops with a BR7ES and a 138 main jet. 160 psi cold compression 4500 ft elevation. Temp 88f

These are the pictures of the BR8ES and a 138 main jet at the same temp and elevation. I have never seen a plug chop uneven like this. Do you think it was a bad plug and that we should do it over? Later that night when it was cooled down completely it still had a compression of 160 psi.

Just to update this thread I am now running a 140 main jet. Also switched to the Mercury Quicksilver gauge and from now on will be basing future compression reads off of the 163 that I get using this gauge.