Performance Carb for Honda clone 4 stroke?

[vyzhion]

Greets all...

I am looking for a performance carb for the 49cc hua sheng honda clone engine. I know there is a version of the stock carb with a fuel pump for more freedom with placement of your fuel tank but I was hoping to find a high performance carb. I have found a couple HP 4-stroke scooter carbs, but I was unsure if those would work. I have been advised by some to go to a go-kart shop but I dunno if we have one of those locally. I'm sure there are a ton online but I'm not really sure what to look for. If anyone can tell me the specs to look for in the carb or if there is a specific model to look for I would greatly appreciate the help. Thanks in advance. Cheers.

-Jesse

PS- I searched for posts on 4 stroke carbs and came up with precious little. :-/

 

[fetor56]

Descent subject.
I have a Honda & it has a good carb from standard but things can always be improved.

 

[Large Filipino]

I'll keep an eye on this thread but your talking 49cc here. I mean what kind of gain are you looking for? May be easier to disguise a 110cc and make that pass for a 49cc.
I'm blabbering anyway. I guess like fetor said,there's always room for improvement,but it may not be that much.

 

[vyzhion]

Well I was reading all about these 2 stroke engines and all the upgrade parts that are available and I started to wonder what might be available for the 4-stroke honda clone engines that many people are using. I just find it curious that there don't seem to be any performance upgrade parts readily available for these engines. You can completely replace every component in a 2-stroke engine with a performance counterpart but I have not seen any for the 4-strokes. I was hoping that someone would be able to point me toward the magic 4-stroke HP supply website.

 

[fetor56]

"magic 4-stroke HP supply website"....naaa i can tell u one doesn't exist.
All this stuff is still in it's infancy but things are starting to move.A friend is swapping over his standard exhaust for something with hopefually better performance,so if he's successful i'll be following.
Right now it's more of a question of trial & error.

 

[MasterLink]

well i took the pipe that came with my 49 cc kit took the muffler cap off ..and pow its a motorcycle sound now didnt go any faster but the sound was really different

 

[ocscully]

Over in the Buy/Sell/Trade area there is a thread from a member named steveo called Honda GXH50 modified. He indicates that he used a "go-kart carb for a 144cc engine. He doesen't state make or model of carb.

ocscully

 

[HoughMade]

I saw that, but is the stock carb restrictive? A larger carb does not automatically mean better performance.

 

[MasterLink]

stevo has a few vids up on u tube and sounds great runs well and he can shift gears with his set up

 

[HoughMade]

I've seen the vids, but I'm not investing in a carb unless I know it will pay off performance-wise. Being able to shift gears is the big performance improvement I see in his vids.

Also, I don't know what engine the carb came from, but I did a little digging on the Honda website. A Honda G150 is 144 ccs, I am going to assume that the carb came from that engine or an equivalent.

The G150 is rated at 3.5hp at 3600 rpm. The GXH50 (49.4 ccs) is rated at 2.1hp at 7,000 rpm (both based on what is in the engine product manuals available on the Honda website). For this rudimentary and theoretical analysis, the hp numbers are not important- I'm just interested in the engine size and power peak rpm- I know alot more than this goes into flow, but it's a start.

With a four stroke, every other revolution of the crank contains an intake stroke, so the 144 cc engine takes in (theoretically) 144 ccs every other revolution for an intake of 259,200 ccs per minute or 9.15 cubic feet per minute at the peak power rpm of 3600.

The 49.4 cc Honda takes in 172,900 ccs per minute or 6.1 cubic feet, at 7000 rpm.

My question is simply this- can the GXH50 benefit from the approximately 50% (49.9%) greater flow? You can slap a 750 cfm carb on a 2 liter engine and, generally speaking, it is not going to make more power.

I would love to know because that would be a fairly easy modification.