Does this plug look alright?

[Street Ryderz]

Tricky business learning to read these plugs I guess... lol. According to the diagram of I read the flat part of the threads I’m jetted rich. According to the heat range burn line I’m “ok”. And as far as cutting the threads back to do the actual “chop” I’m assuming, is that 2mm measured from the top of the threads down or from the base of the insulator up towards the tip of the electrode? Which way is the 2mm measured lol. And what’s the most efficient way to cut the threads back on a plug to read it?

I use a band saw to chop the plug but a rotary tool and cut off disk will work.It's 2mm up from the base that's why the chop is done to make reading that area easier.

 

[CrazyDan]

A hacksaw works fine for us poor simple folks without power tools.

 

[Kpi890]

Okay I full understand a plug chop now! After reviewing your diagram and watching this extremely helpful video. Note this is done on a quad but it applies to our scenario as well. And I believe I have a 5/8” hole saw as well so I can perform the chop as he did here...

 

[Kpi890]

All my jets came in today from GasBike! It’s 23 degrees here today so I may wait until Monday or Tuesday to try them out... what do y’all suggest starting at thinking I need to go richer than what’s already in mine?

 

[6blueoval9]

View attachment 80277 All my jets came in today from GasBike! It’s 23 degrees here today so I may wait until Monday or Tuesday to try them out... what do y’all suggest starting at thinking I need to go richer than what’s already in mine?

I thought the kit may have come with the case it was showing in the pic...bummer....guess I can get one of those plastic craft organizers from Walmart or a craft shop...Still waiting for my jets to show up.

 

[6blueoval9]

It's supposedly a 70 in the carb stock....so just move in 2 size increments up untill the motor 4 strokes then move down in 1 size increments till it doesn't.

The needle though I would put on maybe the 2nd notch from the top to start with as this is the the most common spot they end up being in at least on the 4 groove needles when all is said and done....I can't see being moved down more than the 3rd notch though with your set up.

If your main jet is rich chances are that needle setting will be rich and vice versa with being lean.

Right now you seem lean with needing to compensate going rich on the needle for off idle response.

When you say you have to back off on the throttle to gain more speed you're richening the motor some by taking away some air.

I would put in a 72...move the needle to the second from the top notch and see how that works.

 

[Kpi890]

It's supposedly a 70 in the carb stock....so just move in 2 size increments up untill the motor 4 strokes then move down in 1 size increments till it doesn't.

The needle though I would put on maybe the 2nd notch from the top to start with as this is the the most common spot they end up being in at least on the 4 groove needles when all is said and done....I can't see being moved down more than the 3rd notch though with your set up.

If your main jet is rich chances are that needle setting will be rich and vice versa with being lean.

Right now you seem lean with needing to compensate going rich on the needle for off idle response.

When you say you have to back off on the throttle to gain more speed you're richening the motor some by taking away some air.

I would put in a 72...move the needle to the second from the top notch and see how that works.

Alrighty this is what I’ll try thanks! I’ll report back!

 

[Kpi890]

Alrighty everyone I’m sorry I haven’t gotten a chance to get back on this post but things have been crazy busy this winter. However, I did finally get around to re-jetting my carb! The results aren’t so pleasing though. I took the stock jet out which I’m not sure what size it was and put in a size 72 and gave her a run at WOT. I was able to get up to about 29-30 mph and then when I felt like I was at the top speed for it the engine bogged way down to 23 mph. I kept doing short runs at WOT and it kept doing the same thing, slowly climbing to about 30 and then it would bog down to 23-24???? I took the 72 jet out and threw in a 75 just to see what it would do trying to run it really rich at WOT and there really wasn’t a difference between the 72 and the 75 it did the same bogging at top speed. I was testing this on a slightly downhill road, very slight... does anyone have any clue what might be happening here? Should I try jetting it under 70? Man I was so excited to jet this thing and try these new jets out and I’m a little bummed. Any help would be appreciated!

 

[gary55]

Sounds to rich. What did it do with the stock70?

 

[Kpi890]

Sounds to rich. What did it do with the stock70?

With the stock “supposedly 70” it would get up to about 26 and then bog down very slightly but if I backed off the throttle just a hair it would hit 27 mph but that was about max. I’m wondering if it is 4 stroking and that’s what’s causing it? I thought about trying a 68-69 jet size and seeing what it would do? I have tried all I can to do these “plug chops and checks” but it’s proving very difficult for me to read so I figured I would go by how the engine sounds/feels for my jetting and carb tuning. I just do not want to run it lean at all in fear of overheating and damaging it, is there anything else I can look for to know that it’s lean besides the plug? Would the rpm’s be super high if it’s lean or? Thanks!