Whats the cheapest engine kit that allows you to do 30mph?

[Gavin67]

30mph with a stock kit? The ones under $100 says the top speed is 23mph, and those are 80cc ones. Not looking for anything fancy with the kits if that raises the price, just want to do 30mph with all stock components.

 

[crassius]

all 49, 66, and 70 kits I've seen will do about 30 or more if rider weight isn't too high - saw several older kits fail the run-in and end up with glazed cylinders and were slower

modern motors usually have a more aggressive hone on cyl & do better - new 70cc will often do closer to 40mph with very little run-in needed

 

[Gavin67]

Its strange because my current engine is a 80cc and has a ported exhaust. The max speed is 27mph on a 36t sprocket. Also my engine isn't running rich or lean. I can't figure out why, I did put a offset intake on my engine though recently but that's because its the only way the carb will fit.

 

[Josh5495]

I run a 66cc with 44 sprocket I'm about 250lb it will hit 30 to 36 top with minimum mods just ported cylinder and mod exhaust

 

[FurryOnTheInside]

Any of the kits under $100 will need to have the studs upgraded at the very least.
I started with this type of generic no-name engine and only added the upgraded studs and a head, pretty much everything else I did (to the engine itself) is just modifications to stock parts. It's done 37+ so far with a 42t on 700c, 40+ should be easy.

I would check the intake gasket, could be the carb is rich but extra air is coming in through a leak. Check all the gaskets.

 

[crassius]

I've not seen a 36T sprocket work well on any bike yet - my kits had 36T and I refused them, also refused stupid speed carbs - got special order with parts I trust. All your power is up in the higher revs, so your sprocket should let you get up there.

 

[Lewis]

Which kit did you use? I'm looking for a new kit myself.

 

[crassius]

I buy 20 or 30 at a time from CDH thru their umotobikes.com site, but get them packaged with parts I want - 40mm stroke motors have all been very good

 

[6blueoval9]

I checked out that umoto place...good God they mark up big time....A stock NT carb for $35?...they sell for $9.99 to $15.00 every place else...I won't even continue the list of highway robbery from that place...lol

 

[crassius]

yeah, I sell their kits after assembling the motors and checking all parts for $15 less than they do - in last 70 kits, only had one problem and they sent replacement part on 2-day usps

I almost never buy parts except direct from china, as all retailers are too high - getting a kit is fairly cheap for all the parts. (in fact, most of my parts are real cheap because they're left from a kit after I sell a replacement motor)

I'm picky about kits because a person comes to my shop & I put a kit in their hand and tell them it is good.