Hello y'all. I'm in the final stage of installing my engine kit. It's the 80cc slant plug engine kit from Zoombicycles.com. Anyways I figured I might as well get a good quality plug to replace the original Chinese one. Any recommendations? I'm looking for a good all-around plug wih the proper heat range so engine won't foul. I'll be using the bike for general commuting and just bombing around, not all out speed trials (LOL) so need something that will operate good a idle as well. Any tips/help would be appreciated.
What spark plug for my 80/66cc engine?
- Thread starter meowy84
- Start date
A NGK Spark Plug is a great replacement for these engines such as a NGK # BPR6HIX OR a NGK # BP7HS Advance Auto usually has a larger selection of plugs so you could check there.SBP also carries both of these plugs at a good price. Have fun!
Last edited:
By far the most common plug used to replace stock is the NGK B6HS, the NGK BPR6HIX Aaron recommended is the fancy iridium one, the BP7HS is an extended tip plug with a cool heat range 
Last edited:
I have the iridium BPR6HIX, I never used the stock plug so I can't really compare it to that, but it runs great. What exactly does extended mean? Extended into the motor or larger spark gap? The iridium actually has a bigger spark gap (@ .032") than the BP7HS (@ .027").By far the most common plug used to replace stock is the NGK B6HS, the NGK BPR6HIX Aaron recommended is the fancy iridium one, the BP7HS is an extended tip plug with a cool heat range
Yes, NGK recommends for every 100 horsepower added you should get one level cooler plug. With Japanese plugs like NGK, the higher the level the cooler the plug.
Venice mentioned using either the B5HS or a B6HS plug. What's the difference between the two? I assume the 5 or 6 refers to the heat range? Since I'll mostly be running my bike in the city I'll be running at at low to mid-range speed rather than all out. So which plug would be recommended for that type of riding?
I`m here in fl. and run mine in the city like you do but I use a B7HS without any issues whatsoever....The higher the number the cooler the plug...I beleive a B6 is what the stock plug cross`s over to.....You aren`t going really notice a HUGE difference buy going one step colder/hotter plug...If you go extremly hot on the plug it WILL burn a hole directly though the piston.....But with these motors you could go from a B5HS to a B7HS and not really notice a thing....IT won`t make your motor run colder or hotter....I have a billet head on another one of my bikes which bumped up the compression quite a bit and am running a B8HS NGK plug.....
So just run the NGK B6HS and you should be just fine until you get more performance upgrades done......MY 2 CENTS WORTH.....
So just run the NGK B6HS and you should be just fine until you get more performance upgrades done......MY 2 CENTS WORTH.....
Last edited:
I'm getting my Iridium one from SBP in the mail tomorrow. I'll let you know how it runs and if it made any differences.
As mentioned you have a choice.
Starting with a B6HS is a good middle of the road decision. Here's our plug line up:
SBP NGK Selection - still scrollage down
Extended tip, (indicated by the "P" in NGK part #'s,) means the whole electrode protrudes further into the combustion chamber.
Starting with a B6HS is a good middle of the road decision. Here's our plug line up:
SBP NGK Selection - still scrollage down
Extended tip, (indicated by the "P" in NGK part #'s,) means the whole electrode protrudes further into the combustion chamber.
Would you say there's a noticeable increase in the ease of starting up the bike with your Iridium plug? Mine takes real long to start up and I'm hoping this will help and also help it run a little smoother.
I hesitate to say something like that because your starting issues could be unrelated to your spark plug. All things being equal, sure an Iridium plug will help starting.Would you say there's a noticeable increase in the ease of starting up the bike with your Iridium plug? Mine takes real long to start up and I'm hoping this will help and also help it run a little smoother.
What current plug do you have, and what does it look like?
It is just the stock plug. Not sure exactly but it's the one that was already inside the engine when I received it. And it looks pretty dark and oily. I know this means I need to step up my ratio. I'm running a 24:1 right now and have a little over 350 miles I'm just waiting til I use up my entire gas container to mix up some 32:1.
Thanks stuartracing and Pablo. B6HS it is.
Also, like I mentioned in my initial post my bike is still in the assembly stage. It will be my daily work commuter for the summer months saving me on gas and probably getting me to work quicker than my car in city traffic. ANYWAYS....so my 'modifications' for this build are geared strictly towards ease of operation and reliability and so far the list of planned mods includes: the dual pull brake lever, a fuel filter and a good quality plug. Are there any other quick, inexpensive mods or upgrades that these Chinese engines greatly benefit from right off the bat?
P.S. These kits should really come with a fuel filter standard. I mean come on it's only a buck or two in cost.
Also, like I mentioned in my initial post my bike is still in the assembly stage. It will be my daily work commuter for the summer months saving me on gas and probably getting me to work quicker than my car in city traffic. ANYWAYS....so my 'modifications' for this build are geared strictly towards ease of operation and reliability and so far the list of planned mods includes: the dual pull brake lever, a fuel filter and a good quality plug. Are there any other quick, inexpensive mods or upgrades that these Chinese engines greatly benefit from right off the bat?
P.S. These kits should really come with a fuel filter standard. I mean come on it's only a buck or two in cost.
Oh by the way I forgot to mention that my engine is the 80cc slant head version from zoomcycles. My engine is still in the box and I haven't had a chance to take the head off to see how far the stock chinese plug protrudes into the combustion chamber so I hope I won't have any clearance issues with the B6HS plug (I assume that since the BP6HS is just a higher quality version of the stock plug there won't be any pistin/plug interference issues...?).
Thanks Aaron, already thought of that. I'll definitely have to do something with the exhaust gasket itself for sure. Without running to the garage to look at it and going from memory alone I recall that the gasket appears to be some form of fibrous material sandwiched between two metal sheets (that's the best way I can describe it LOL). Anyways, the reason I say I need to work on it is that when I put it on the exhaust port it is a bit off center and covers (i.e. restricts) about 30% of the exhaust port opening. So I'll just have to 'dremel' the hole of the gasket a bit to get a closer match to the actual contours of the exhaust port.
Then of course I'll be doing the usual as suggested in one of the engine prep threads taking the side covers off to make sure there's no metal filings lurking around from the manufacturing process. One thing I hope is that there aren't any shavings inside the crankcase itself because I really don't want to have to split the engine and risk damaging the gaskets and having to get a new gasket set for it. *sigh*
Then of course I'll be doing the usual as suggested in one of the engine prep threads taking the side covers off to make sure there's no metal filings lurking around from the manufacturing process. One thing I hope is that there aren't any shavings inside the crankcase itself because I really don't want to have to split the engine and risk damaging the gaskets and having to get a new gasket set for it. *sigh*