Hard start fix?

[xxmountain]

I've recently complete 2 66/80cc bikes. Both have run around 6 miles. They can start, however it takes forever, closer to maybe 15 minutes to get going unless already hot from running. I am running a 30:1, with .2 spark plug gap, all stock kits. As far as I can tell theres no flooding since the carbs have the design where the bleeder/primer is on the very bottom. Compression is great, the wheel skids well when releasing the clutch. I don't know how possible it would be to have 2 bad spark plugs from factory, but I plan to get ngk's later today. Any recommendations on making them start easy would be appreciated.

 

[DAMIEN1307]

with .2 spark plug gap,

Whether your .2 is either in thousandths of an inch or in mm, your gap is way off.

.2 thousandths is 5.06mm
.2mm is 0.0071 thousandths

You need to have your plugs gapped at;
.025 thousandths, which is 0.635mm

I also advise getting rid of those junk Chinese "Z" type spark plugs and chuck them in the trash, there are many stories here in the forums where people tell us they just don't work right OOTB.

Replace those plugs with NGK-B6HS or its resistor type NGK-BR6HS

 

[darwin]

 

[xxmountain]

Yeah, .02 or so is what I've been doing on the stock. I went ahead and got 4 new plugs earlier and installed the E3.10 in each bike. The started in around 50 feet. I'm letting them cool and if they don't start easy still I'm switching them to my NGK BP6HS's. I hadn't seen this post before I went shopping at 730am lol. I'm hoping these plugs are okay, they're the best I could source locally.

 

[DAMIEN1307]

NGK BP6HS's

NO...The "P" is a protuding tip plug which may or may not get hit with the piston depending on the motor...You want NGK-BR6HS

 

[Mossy]

E3 . 32 not just any E3... Or ngk or whatever kinda fits because that's all they had... Break-in at 24:1 oil... Then 32:1

 

[DAMIEN1307]

Yeah, .02 or so is what I've been doing on the stock. I went ahead and got 4 new plugs earlier and installed the E3.10 in each bike. The started in around 50 feet. I'm letting them cool and if they don't start easy still I'm switching them to my NGK BP6HS's. I hadn't seen this post before I went shopping at 730am lol. I'm hoping these plugs are okay, they're the best I could source locally.

E3 . 32 not just any E3... Or ngk or whatever kinda fits because that's all they had... Break-in at 24:1 oil... Then 32:1

This plug from NGK is a step above their regular line of plugs and you can get it from Amazon for $6.13.

https://www.amazon.com/NGK-BR6HS-10-Standard-Spark-Plug/dp/B000F0BYXW

 

[DAMIEN1307]

I went ahead and got 4 new plugs earlier and installed the E3.10 in each bike.

E3 . 32 not just any E3

I am not a big fan of the E3 series plug for what I consider to be a major design flaw...In the pics below, notice the upper ceramic construction of the NGK plug, It is "corrogated" to prevent spark "flashback" from either faulty, or in our case, cheap spark plug boots on these Chinese kits.

The E3 plugs do not have this as a construction feature in their plugs.

What happens is the flashback goes beyond the ceramic stem and hits the metal base of the plug...This will overheat things quite a bit as well as it can also result in possible spark plug hole thread damage channeled through that metal base of the plug.

The very bottom pic will show you an example of flashback that happened to one of our members spark plug recently as well as the fact it damaged his threads as well.

 

[Freddy Snottgrass]

The E3 plug pictured above is mine. That happened after about a 30 mile ride with a 5 minute break halfway. I won't buy an e3 for my MB again. My cylinder head is most likely ruined (plug threads). I don't know yet.

 

[Mossy]

The Bosch W8AC (an 8 is a 6 in ngk ) were a few dollars, 16 for $ 35...they're originally for a 1969 1.5L VW beetle plugs...