Jetting and spark plug experts please help

[nestz]

Wow - great info! Thanks everyone. I will try and attempt this tonight (if I can get the kids to bed early). All going well I'll report back later.

[gg3]

My bad,bowl doesn't need to be removed but I struggle to get the pilot jet out,hands are too big.Kept me out of gynecology school as well.

[nestz]

Thanks for the step by step guide gg3, it was a massive help and made the job easier than expected. Here's what I found:

Pilot: 42, Needle: N1EF, #3 clip (third slot down from the top), Main:175

According to the manual this set up is pretty much perfect for my temperature and altitude - so why the lean looking plug?

Also how long does it take for a new spark plug take to show colour so you can read it?

The reason I ask is, after I rode in the sand for that hour and discovered the lean spark plug, I wanted to test if it was lean just on the main jet, so I let it warm up for a few mins, then rode 5mins down the road using 1/4 to 3/4 throttle, with maybe a few squirts of WOT. This was on hard pack so not under load like I was in the sand. I checked the plug again and it looked pretty much the same.

Is 5mins enough to read a plug? If so why is it so lean even on hard pack terrain?

Finally does fuel octane have a major effect on jetting? Like is there much of a difference running 91 as opposed to 98.

[gg3]

Nice work!
That needle is not great but still wouldn't have expected that white a plug?
But some more informed guys will comment on that.Possibly sucking air in somewhere?
I run 42 pilot NEDW needle clip #3 175 main at similar temp & altitude with no problems.

[memphis2857]

If it were me I would put a 180 main in it to start and then go from there.

Plug reads are very deceiving and not a very good way to jet a bike. It gives you an idea but you need to jet more based on performance than how the plug looks. Also making a jetting change and then riding up and down the street or some other no load situation is not a good way to jet. This is not how you normally ride therefore you shouldn't be jetting to those circumstances. I learned all this the hard way.

Also it will be next to impossible to get the jetting dialed in until you get your squish band corrected.

I learned all this the hard way. I chased jetting for months and never could get it right until I fixed the squish and went to a riding area and put my jets and tools in my pack and went for a ride. Had jetting sorted in less than 10 miles and haven't touched it since.


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[nestz]

Squish band? This is getting complicated. Is this what all gasgas owners have to do to get their bikes running right?

I guess for now I just want to ride my new bike and not worry about it melting because its too lean.

If I put a 180 main jet in will it be safe to ride? Should I make any other changes while its open e.g move the clip position or change the needle? People have mentioned the NEDW needle - is this a better needle and what difference will it make?

[memphis2857]

The NEDW takes all the "hit" out and makes the power very smooth vs. explosive like it is now with the N1EF needle. The 180 should make it safe to ride just keep your eyes and ears open and listen for a lean bog and smell for a burnt smell from the exhaust. Maybe after about 30 minutes of riding have a look at the plug just for peace of mind.

Squish band is a cheap $75 mod in which you send your head off and they mill it down to make the engine more efficient, responsive, and boost power. Well worth the money


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[nestz]

Originally Posted by memphis2857

The NEDW takes all the "hit" out and makes the power very smooth vs. explosive like it is now with the N1EF needle. The 180 should make it safe to ride just keep your eyes and ears open and listen for a lean bog and smell for a burnt smell from the exhaust. Maybe after about 30 minutes of riding have a look at the plug just for peace of mind.

Squish band is a cheap $75 mod in which you send your head off and they mill it down to make the engine more efficient, responsive, and boost power. Well worth the money


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Thanks memphis.

By 'lean bog' do you mean that it struggles to get 'on the pipe' with WOT?

After half an hour should my spark plug look a brown tan colour? If it doesn't should I not ride it?

Also does running it on 91 octane make a difference with jetting?

[memphis2857]

Originally Posted by nestz

Thanks memphis.



By 'lean bog' do you mean that it struggles to get 'on the pipe' with WOT?



After half an hour should my spark plug look a brown tan colour? If it doesn't should I not ride it?



Also does running it on 91 octane make a difference with jetting?

Lean bog = buuwaaaa sound if that makes any sense. If it's rich it will burble and sputter. Not real sure how to explain it any other way.

After 30 minutes the plug should tell you if it's safe or not. Riding it will be your judgement call. I rode a whole race on my bike and it was so bad lean on the main it would just nose over at wot. But i short shifted and tried to stay off the pipe as much as possible. Not a good idea but I did it with no damage in the end. That's your call to make

Octane won't make a huge difference but it will change your jetting some. It's best to pick a fuel (ethanol free if possible) and stick with it all the time. I run VP 110 because I can buy it out of a gas pump 5 miles down the road and it is leaded and no ethanol.


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[nestz]

So I put in the 180 main jet and switched to a NEDW needle on clip #3 and put a new plug in it (br8es), took it for a ride up the beach mostly WOT, Checked the plug and looks like the original pic I posted (white as snow). Then I took it into some firm packed single trails, riding mostly low rpm, checked plug again, still white. Whats up with this bike? So frustrating.