My GX200 Clone

[slideways]

I saw earlier someone posted the carb throat measurement. That is not the correct measurement for the venturi portion. It is right around .615. Afterwards it may be larger but it is not 19mm since those carbs are an upgrade for a hotter build setup.

 

[Doc Sprocket]

I measured at the mating surface. I don't have a caliper that will reach deep enough to measure the venturi area.

 

[slideways]

Ah ok. I get most of my clone info from the kart racing boards. They stock classes have a very strict gauge that cant pass through the venturi and that's the measurement they have to be under. Trick to power is getting it right there but no more since the carbs on clones have alot of variances.

 

[bgtcars]

the plug in the pilot adj hole is to keep from adjusting carb like old ones . epa's idea less emissions US is only place used. sediment bowl stops big stuff and water/condensation from getting into float bowl, just a good pre filter

 

[devino246]

the plug in the pilot adj hole is to keep from adjusting carb like old ones . epa's idea less emissions US is only place used. sediment bowl stops big stuff and water/condensation from getting into float bowl, just a good pre filter

I believe we had already figured that out.

@toystory, any progress?

 

[808moparskate]

I was on the internet last night finding mods for myself and came a acrooss a websaite called affordable go karts and they have everything on how to remove govener and all the basic mods. I wanna do a semi mod motor for my go kart and i put a package together that costs 180 dollars this includes a metal cam with higer lift on the exhaust and intake and longer duration (no more plastic cam) this also includes an aluminum flywheel so i dont have shrapnel in my back also some odds and ends like 18pound valve springs tehn differant mods you can do for free but my kit also included an 8 degree timing key with a bunch of stuff and you got a pretty good motor i must say.

 

[r_chez_08]

The stock camshaft on these motors is not plastic?

 

[devino246]

I was on the internet last night finding mods for myself and came a acrooss a websaite called affordable go karts and they have everything on how to remove govener and all the basic mods. I wanna do a semi mod motor for my go kart and i put a package together that costs 180 dollars this includes a metal cam with higer lift on the exhaust and intake and longer duration (no more plastic cam) this also includes an aluminum flywheel so i dont have shrapnel in my back also some odds and ends like 18pound valve springs tehn differant mods you can do for free but my kit also included an 8 degree timing key with a bunch of stuff and you got a pretty good motor i must say.

First, as stated several times by several people, the stock flywheel WILL NOT explode unless the flywheel has been tampered with. Its a myth. Second, the stock cam on Hondas or clones arent plastic. Third, if your removing the governor and doing all this other stuff, you really need to replace the stock connecting rod with a billet one. Theres a decent chance of the stock rod breaking and destroying your engine.

I modded my clone with the following:
Billet connecting rod
Removed governor
18lb valve springs
Port and polish head
High flow air filter
High flow DIY exhaust
(will be rejetting carb this week)

Spent like $120. BTW, before doing anything, make sure you've read up on your 4 stroke engine theory.

 

[Doc Sprocket]

Ahh, in no particular order-

@bgtcars- we do already have all that stuff nailed down- thanks.
@Devino- No real progress lately. I've been busy with several things, and will not be doing much else with the engine until I get my gasket set in.
@808mopar AND Rchez- Plastic camshaft? No. A plastic camshaft wouldn't survive 30 seconds. The gear is plastic, though. Presumably to reduce noise/friction.
I have no worries about that. I've seen plastic gears/sprockets in use in engines many times in the past, with no failures.

 

[r_chez_08]

Yeah I knew it wasn't plastic cos I had the sidecover off my clone to remove the gov. I was just questioning 808mopar.

 

[dan]

I modded my clone with the following:
Billet connecting rod
Removed governor
18lb valve springs
Port and polish head
High flow air filter
High flow DIY exhaust
(will be rejetting carb this week)

Spent like $120. BTW, before doing anything, make sure you've read up on your 4 stroke engine theory.

so obviously u have not done ur reading on 4 stoke engines as u would know that polishing the head makes it not flow as well. as wen the rough finish is in the port the air molecules get stuck in the little rough tooling marks or pitting sort of thing. the air then goes into a swirl in these making the air coming in to the intake flow faster. As the air coming in WILL flow faster across the swirling air then it will on the polished part.

thanks for taking the time to read this. cheers, Dan

 

[newrider3]

so obviously u have not done ur reading on 4 stoke engines as u would know that polishing the head makes it not flow as well. as wen the rough finish is in the port the air molecules get stuck in the little rough tooling marks or pitting sort of thing. the air then goes into a swirl in these making the air coming in to the intake flow faster. As the air coming in WILL flow faster across the swirling air then it will on the polished part.

thanks for taking the time to read this. cheers, Dan

Port and polish is just a general term. Most of the time you will port both the intake and exhaust (to remove casting imperfections) and only polish the exhaust port. By leaving the intake slightly rough it doesn't increase flow, it helps the mixture stay atomized.

 

[robbie]

Air will flow with less drag over a rough surface than a smooth one. In airplanes they call this "laminar flow".

If you have a smooth surface, the air drags against it.

A rough surface traps a layer of air, and the main body of air drags against the small air layer.

 

[devino246]

Port and polish is just a general term. Most of the time you will port both the intake and exhaust (to remove casting imperfections) and only polish the exhaust port. By leaving the intake slightly rough it doesn't increase flow, it helps the mixture stay atomized.

Yep. Exactly what I did.

 

[Doc Sprocket]

That's very interesting. I have heard the same is true for boat hulls, being that a very slightly (near-microscopic) rough texture will make for a faster hull because the water will slightly adhere to an ultra-smooth surface.

 

[robbie]

That's very interesting. I have heard the same is true for boat hulls, being that a very slightly (near-microscopic) rough texture will make for a faster hull because the water will slightly adhere to an ultra-smooth surface.

Yeah, that's a word I forgot to include. Near-microscopic. These surfaces are rough like 220 grit sand paper.

 

[808moparskate]

The stock camshaft on these motors is not plastic?

the gear is and so are the lobes but they are formed onto a metal rod if thats what you mean?

 

[Doc Sprocket]

The lobes are NOT plastic. Please re-read post #49.

 

[newrider3]

Plastic camshaft? No. A plastic camshaft wouldn't survive 30 seconds. .

They may not be comparable in durability to an average iron cam, but they do exist. Tecumseh OHH-series kart motors, and Briggs Quantum flathead vertical motors are two that come to mind, that I have personally taken apart. The lobes are indeed plastic.
/threadjack

 

[jareeB]

toy story you will need a billet rod the is the weak point, if the motor turns over 4k you will break the rod, just spend 60 bucks and get a billet rod also i would by a flat top piston well you at it.

rod

flat top

also the rings that came with the motor can be used, but if you used the engine before to break it in, then i wouldn't risk using the piston wist pin clips again. i have built my modded clone still have to start it and people over a oldminibike.com said that the billet rod is mandatory