Flying Horse 66cc Epa Kit Carb Question

[guitarfanatic21]

Hello all,

A friend of mine owns a motorized bike shop and as an early gift for Christmas, he gave me the Flying Horse 66cc EPA certified kit. It runs on a 100:1 oil ratio and I'm using Opti-2 oil because I couldn't find Amsoil Saber in my area like the manual suggests and Opti-2 also runs on 100:1. It has some good power and accelerates pretty quickly.

I do have a question about the carb. I've only ever used NT carbs like my other PK80 bike that has 1900 miles on it but I believe this one is a CNS? I've attached a picture of the kit. While it does have good acceleration, I do find it to 4-stroke at higher speeds of over 20 mph or under rapid acceleration. It only has 60 miles on it right now maybe it won't once it breaks in I have no idea.

Does it have anything to do with the 100:1 oil ratio and can it be tuned by a jet change? It requires a 100:1 ratio due to the catalytic material in the muffler. I do really like the kit maybe a jet change is all it needs. It has an NGK B5HS plug currently. I am just unfamiliar with this carb.

Thanks so much!

 

[guitarfanatic21]

 

[gary55]

View attachment 84810

That's not the CNS. It's a Dellorto clone. They tend to run rich. Jetting down will help. I will also ad that every body has their preferences as to oil mixes. I use Amsoil at 32:1. Others who's opinions I respect like the Opti-2 at 50:1. I think that 100:1 is for engines that are far better engineered, and with far better quality of materials than the ones we are using. If it needs it for the muffler I would s**t can the muffler to make the engine last longer.

 

[LewieBike]

This engine's muffler is a catalytic converter, so running a thin oil mix is meant to keep it from getting oil fouled and losing it's ability to burn clean. I think any decent, pure synthetic 2 stroke oil would work with this engine, like Lucas.

But I can't help but think 100:1 is a little too lean for oil, maybe 75:1 or 60:1, I'd feel comfortable with. It's an aircooled engine and not force air cooled like weedeaters or chainsaws, so the temperature will be all over the place. My Husky 28 cc weedy runs a catalyst and it's fine with 50:1 using Lucas only. I used to work at a Scooter shop and all of our 50 cc bikes ran catalytic mufflers, they were oil injected and I'm taking a WAG the average fuel oil mix was somewhere near 50:1 ~ 80:1 Once warmed up those engines ran almost odorless and without visible smoke.

 

[Tyler6357]

I use Opti-2 for both of my bikes at about 95:1 using the same carb as you are. You should definitely jet down, leaning it out will stop the 4 stroking. I love the Opti-2 and have been using it since my first start, over 2000 miles ago. I know it isn't as heat resistant as other 2 stroke oils but it burns so clean with almost no smoke, less carbon build up, and no oil clogging up my exhaust and the truth is, these engines don't get hot enough to cause Opti-2 to actually break down.