Spark Plugs???

Sideshowbob

Sideshowbob

New Member
I just got a new 68.5 cc chinese 2 stroke and I noticed that the spark plug is very different from the one on my 49cc skyhawk. The skyhawk has a tripple fire type plug LD Z4JC and the new slant head I got has a mutch larger plug with no real markings other than qq. I have no clue what it is. I have also heard about using NGK B8HS and or B9HS. Can someone like a sight old timer please explain spark plugs and your preferences. Thanksdance1
 
The established favorite here is the NGK B6HS. Heat ranges up one and down one, 5 & 7 have been used successfully too. The heat ranges you listed 8 & 9, are probably too cold for our purposes I use the 6 plug but I've also had very good luck with a Champion plug, number 811 (L82C).
The kit supplied plugs have been notorious for early failure which can cause hard starting, poor performance and they've even been known to fail completely.
The NGK plugs are usually available at most good auto parts stores. O Riley(formally Checker) has them in stock as a rule.
All plugs that you'll get from auto parts stores will either require a new, better spark plug boot, or removal of the top (tip) of the plug if you're using the kit supplied boot which snaps onto the threaded portion left when you remove the tip. The tip can be unscrewed with the help of pliers or vicegrips.
Tom
 
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I second the motion of 2door...I used the NGK B6HS...in fact you told me about them and I have used that with no problem.
 
Mine runs a little mo betta with a BP6HS, which is the same as a B6HS, but has an extended tip.

The stock 3 prong plug is poopoo.
 
Crazy Grandma said:
I have had 3 boots lost 4 front mount bolts 3 fuel filters huh. Got a ngk b6hs now what boot is compatablelafflafflafflafflaff
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sick bike parts plug wire or any Briggs type. The Chinee plugwire/boot are made from 6 pieces to replace what we do with 3 parts plus they are made in a toy factory.

A small engine repair place should be able to help you out on getting a better set-up.
 
if anything you can replace the boot and connector with an automotive grade one, borg-warner makes just clips and silicone rubber boots you can order from a auto house(ment for custom made spark wires) and may still make racing copper core types that may work for the engines
 
There's already many many pages devoted to spark plugs so I didn't want to start a new thread but I do have a question. I've not seen anyone bring this up even though it seems the majority of us use the venerable NGK plugs in our 2 stroke engines.

On the side of the box are two small illistrations. One shows what obviously is the correct way to turn the plug to tighten it. That's apparent. But there is another one which, pictured below, shows the plug gasket area and indicates some numbers, fractions actually, 1/16, 2/3 etc. and for the life of me I can't figure out what the folks at NGK are trying to tell me. Anyone have an answer, or a theory. I have a couple of theories but I'll wait to see what you guys think.

Hint: One plug uses a gasket, the other is gasketless.

Tom

EDIT: LOL, just figured it out. Funny, I use a torque wrench. :)
 

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2door said:
There's already many many pages devoted to spark plugs so I didn't want to start a new thread but I do have a question. I've not seen anyone bring this up even though it seems the majority of us use the venerable NGK plugs in our 2 stroke engines.

On the side of the box are two small illistrations. One shows what obviously is the correct way to turn the plug to tighten it. That's apparent. But there is another one which, pictured below, shows the plug gasket area and indicates some numbers, fractions actually, 1/16, 2/3 etc. and for the life of me I can't figure out what the folks at NGK are trying to tell me. Anyone have an answer, or a theory. I have a couple of theories but I'll wait to see what you guys think.

Hint: One plug uses a gasket, the other is gasketless.

Tom

EDIT: LOL, just figured it out. Funny, I use a torque wrench. :)
Click to expand...

Some plugs are beveled on the bottom, and some are flat with a crush washer.

This is what I think they're trying to say.

After installing the plug all the way in by hand, if the plug is beveled at the bottom, then turn it 1/16 of a turn more. If the plug is flat and has a crush washer, then turn it 1/2 to 2/3 of a turn more.
 
biknut said:
Some plugs are beveled on the bottom, and some are flat with a crush washer.

This is what I think they're trying to say.

After installing the plug all the way in by hand, if the plug is beveled at the bottom, then turn it 1/16 of a turn more. If the plug is flat and has a crush washer, then turn it 1/2 to 2/3 of a turn more.
Click to expand...

I'm expert at understanding stupid.
 
biknut said:
I'm expert at understanding stupid.
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Yeah, after studying it for a few minutes I figured it out. Really a stupid way to do it. I haven't seen many wrenches with a radial dial to indicate the degree of rotation :)

Hey, maybe I should event one for people who don't know how to use a torque wrench.

Set the dial for 1/16 of a revolution, or 2/3, 1/2, whatever, and when it gets there, it releases and you bust your knuckles on something.

Tom
 
2door said:
Yeah, after studying it for a few minutes I figured it out. Really a stupid way to do it. I haven't seen many wrenches with a radial dial to indicate the degree of rotation :)

Hey, maybe I should event one for people who don't know how to use a torque wrench.

Set the dial for 1/16 of a revolution, or 2/3, 1/2, whatever, and when it gets there, it releases and you bust your knuckles on something.

Tom
Click to expand...

I was thinking along the lines of a built in cattle prod. That would stop over tightening lol.
 
If I might add a use-full tip for those who don't already know...

Use a short piece of fuel line stuck onto the spark plug as a handle to screw it in or out.
 
Trey said:
If I might add a use-full tip for those who don't already know...

Use a short piece of fuel line stuck onto the spark plug as a handle to screw it in or out.
Click to expand...
Used that method for years when I had an engine that the plugs were hard to reach and you couldn't see the plug holes in the head. I haven't done auto mechanics for years but I'll bet some of today's cars are harder than the ones I used to work on. I've looked under the hoods of a few new cars and couldn't even see the plugs, let alone the holes they go in. My spark plug sockets have a rubber grommet that grips the plugs. Same principle as the old hose trick.

Thanks for the tip, Trey.

Tom
 
Oooo yeah. I just tuned an 87 Seville and it absolutely had to go on a lift to get to the rear plugs. So tight in that sidewinder. Gotta love those sockets with the o-ring, eventually I'll get more than one!
 
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