Spark plug mystery

Drake Abrahamsson /

Just performed my first plug chop and I got an interesting result.. One side of the insulator is near white while the other is a dark brown! Not sure how I’m supposed to take a plug chop with two different colors haha. Any help would be greatly appreciated!

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Re: Spark plug mystery

based on your plug alone, i would say that you are overjetted with a head leak

also, inb4 "thats not a plug chop"

Re: Spark plug mystery

Drake Abrahamsson /

> alex . Wrote:

> -------------------------------------------------------

> based on your plug alone, i would say that you are overjetted with a

> head leak

>

> also, inb4 "thats not a plug chop"

Interesting! Here’s what I’m running:

70cc Treats kit

Hi comp head

14mm bing; 72 jet, 2.20 atomizer, 24 slide

Metal mesh air filter

Tecno circuit pipe

Just checked (like literally just right now) for leaks and didn’t find any. My bike dies after a minute or two of riding which I suspect is fuel starvation because I had to set my float pretty low in order for it to not leak. The paler part of the insulator faces downwards towards the exhaust pipe. Also I’m having some issues with some buildup on the piston crown and cylinder head. I’m using Lucas Semi-Synthetic at 50:1. I had some point skipping so I replaced & correctly oiled the felt pad as well as sanded down slight pitting on the cam lobe. Last time I checked timing it was 15* BTDC. Re-checking for correct timing/lack of skipping is next on my list because it’s just too difficult to do with a bike that just dies and no extra hands. Any other ideas?

Re: Spark plug mystery

Drake Abrahamsson /

This is after trying a 75 jet.

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Re: Spark plug mystery

Charles McCusker /

you shouldn't be adjusting your float to stop it from leaking on a bing. it's either your gasket and/or your float needle. fix that and set your float height correctly.

Re: Spark plug mystery

Drake Abrahamsson /

> Charles McCusker Wrote:

> -------------------------------------------------------

> you shouldn't be adjusting your float to stop it from leaking on a bing.

> it's either your gasket and/or your float needle. fix that and set your

> float height correctly.

I’ve polished the float needle seat to hell, tried two different brand new float needles, replaced float pin, replaced float, and replaced the gasket. This is the only thing that makes it not leak. It’s not at an extreme angle either, only a bit above parallel with the float bowl seat.

Re: Spark plug mystery

BasicPlugReading1.jpg

Re: Spark plug mystery

Drake Abrahamsson /

So if my spark plug is pale on one side and brown on the other, what would that mean?

Re: Spark plug mystery

Overpriced Parts /

You were looking at a all around spark plug reading which means nothing ever!

A correct plug chop is to put a new plug-in after bike is fully warmed up and takeoff and run a 1 mile at full throttle run, shut it down and put it in neutral so unburnt gas can’t be thrown on the plug!

Then chop it up open and read the ring way down below, you don’t have to chop it off you could read it with a magnifying glass,

Problem you can’t do that with the automatic clutch Moped that will keep throwing raw gas on the plug even after you hit the Killswitch for certain amount of time

so most Moped plug chops don't matter at all,

You got a learn to tune by ear and feel and going up hills and such,

I’m lucky because I have a 1.3 mile private Road that has two small hills so I look at the speedometer when I hit the first hill and when the second hill hits I know where I’m supposed to be at on stock, stock modified, kitted super street and full-blown kited speeds,

Ya sucks that most people don’t have what I have which is basically a small race track to tune on, I also got 4.5 mile straight away that’s 50 to 55 mph limit St route that I could go full bore on to tune for temperature,

Bring in here if you want to tune it for a super street!

Re: Spark plug mystery

Learn more about reading spark plugs.

Re: Spark plug mystery

Drake Abrahamsson /

Thanks for all of the effort you put in to your responses Ken! I really appreciate it. It sucks because this ped was going 45 mph a month ago before it stopped working and a thick coating built up on the piston crown. Since then I’ve stopped the carburetor from leaking and re-set timing and now it won’t even go 30. I’m truly at a loss as to why it won’t run properly.

Re: Spark plug mystery

Drake Abrahamsson /

Is this normal? Or should all of this be squeaky clean? Grasping at straws here

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Re: Spark plug mystery

> Drake Abrahamsson Wrote:

> -------------------------------------------------------

> Thanks for all of the effort you put in to your responses Ken! I really

> appreciate it. It sucks because this ped was going 45 mph a month ago

> before it stopped working and a thick coating built up on the piston

> crown. Since then I’ve stopped the carburetor from leaking and re-set

> timing and now it won’t even go 30. I’m truly at a loss as to why it

> won’t run properly.

Where was the timing before?

There will be some carbon build up on a piston. In fact, it looks like too much piston wash on that crown to me, which reiterates Alex's remark about being too rich. (Too much fuel)

Re: Spark plug mystery

Drake Abrahamsson /

It was closer to 16-17deg I can’t quite remember but it got WAY too hot that day so I set it to 15deg and got a temperature gauge. I’ll go down a jet size from 72 and see what that does.

Re: Spark plug mystery

> Drake Abrahamsson Wrote:

> -------------------------------------------------------

> It was closer to 16-17deg I can’t quite remember but it got WAY too hot

> that day so I set it to 15deg and got a temperature gauge. I’ll go down

> a jet size from 72 and see what that does.

Look for air leaks first before down jetting. Very important, like Alex said, an air leak may be masking the need for more fuel.

Re: Spark plug mystery

♣Slew Foot♣ /

When I look at the topic you got to remember I got medical marijuana and it says spark plug Ministry in the way you're holding it I just want to say the threaded end goes into the engine

Re: Spark plug mystery

Drake Abrahamsson /

> ♣Slew Foot♣ Wrote:

> -------------------------------------------------------

> When I look at the topic you got to remember I got medical marijuana and

> it says spark plug Ministry in the way you're holding it I just want to

> say the threaded end goes into the engine

Sorry what? Am I holding the plug like a kook? hahaha

Re: Spark plug mystery

Drake Abrahamsson /

> live ɘvil Wrote:

> -------------------------------------------------------

> > Drake Abrahamsson Wrote:

>

> > -------------------------------------------------------

>

> > It was closer to 16-17deg I can’t quite remember but it got WAY too

> hot

>

> > that day so I set it to 15deg and got a temperature gauge. I’ll go

> down

>

> > a jet size from 72 and see what that does.

>

> Look for air leaks first before down jetting. Very important, like Alex

> said, an air leak may be masking the need for more fuel.

I sprayed carb cleaner over all the joints (carb, intake, base, head) and nothing happened. Could there be a blown seal maybe? I replaced the crank,seals,bearings around 2 months ago.

Re: Spark plug mystery

And this thing does not 4 stroke on top end?(edited)

Re: Spark plug mystery

Drake Abrahamsson /

> live ɘvil Wrote:

> -------------------------------------------------------

> And this thing does not 4 stroke on top end?

It just dies if I take it past half throttle. It also doesn’t start if I use the choke, but will start regularly.

Re: Spark plug mystery

What's the temps now?(edited)

Re: Spark plug mystery

Drake Abrahamsson /

> live ɘvil Wrote:

> -------------------------------------------------------

> What's the temps now?

Didn’t see it get over around 175 today while test riding today but that’s not saying much considering I couldn’t even run it at WOT

Re: Spark plug mystery

♣Slew Foot♣ /

Okay here's the dealio when you're dealing with a Tomas those two little lines on the case Center your stator on dead center between to start provided you didn't put up thick gasket on the base that should be a safe starting point the problem you're having right now is you do not have enough air the carbs is Tiny so ditch any air box or filter put pantyhose or a t-shirt held by a copper wire or rubber band round of mouth of the carb start with a 74 jet and work down 50 to 1 ratio of istica two-stroke oil that way everything's safe to start if you have a timing light more power to you but it equates the one mmmm of movement on the stator is equal to 1 degree also you can mechanically measure from Top Dead Center as it would be 2 millimeters before top dead center is where you wanted to fire

Re: Spark plug mystery

Drake Abrahamsson /

Slew I’m running a puch e50 with a 70cc treats kit. I will try to take the air filter off, that’s what the PO has done

Re: Spark plug mystery

Did you check that decomp valve for a leak as well? The ignition seal?

Re: Spark plug mystery

Does that spark plug have a gasket on it? Just can't make it out in the pics.

Re: Spark plug mystery

Drake Abrahamsson /

> Don Ohio Wrote:

> -------------------------------------------------------

> Does that spark plug have a gasket on it? Just can't make it out in the

> pics.

Using a temp gauge so I cut off the gasket and replaced it with the brass ring like (I think) you’re supposed to do.

Re: Spark plug mystery

Drake Abrahamsson /

This is for an E50- no decomp valve & I’m not sure what the ignition seal is but maybe it goes by a different name?

Re: Spark plug mystery

Drake Abrahamsson /

> Drake Abrahamsson Wrote:

> -------------------------------------------------------

> > Don Ohio Wrote:

>

> > -------------------------------------------------------

>

> > Does that spark plug have a gasket on it? Just can't make it out in

> the

>

> > pics.

>

> Using a temp gauge so I cut off the gasket and replaced it with the

> brass ring like (I think) you’re supposed to do.

Which concerns me after reading some text from Jennings which discussed the crucial nature of spark plug depth. The copper ring is significantly thinner than the crush gasket that comes with the plug. I’ll have to bust out the calipers and measure the difference between the crushed gasket and the brass ring. Could be a difference in compression as well because before I had the temp gauge I felt more resistance when pulling the clutch lever and starting it

Re: Spark plug mystery

i always just take a sanding drum on a rotary tool to the temp gauge so it can slip on the threads freely, and run both that and the gasket

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