Honda clone (196/208) running rich?

[BDG]

Hey guys first post here! Bought a mini bike second hand off a guy. Has a Powerfist motor on it, unsure if it's a 196/208. They're basically the same from what i read anyways. I proceeded to straight pipe (1") it and externally remove governor (yes yes i know remove it internally, I will very soon.) Anyways, it was running great, pulled good sounded awesome. I decided to relocate the fuel tank and jet the carb (.035 bit). Now when i hold up the back tire and rev it she gives a puff of black smoke. I mean its nothing really insane but you can tell it's definitely running a bit rich. It still runs and drives but it's running a bit warmer now and seems to be almost more sluggish? Tone of the engine changed when i jetted it as well, quite a bit deeper, especially under acceleration. So my question is, am I fine to run it like this or should I order an aftermarket air filter? Performance parts to Canada are rather expensive due to shipping so don't want to order anything I dont have to. Also, would advancing the timing remedy this?

tl;dr : I jetted carb (.035) and now runs rich. What do I do to remedy this? Advance timing or aftermarket air filter? Or is it fine to run like this?

Thank you for any help in advance!

 

[minikenny]

Besides what you mentioned you need a better flywheel and connecting rod. Those chinese ones are known to let loose at the worst time...

On your fuel mixture - I think you answered your own question, and I am assuming you know how to read a plug. It does sound rich. So you need more air or less fuel. Take the cover off your air box yet? That might get you more air flow. You can make a carb adapter out of a PVC pipe cap and get a cheap clamp on cone filter that fits.

Or get another stock jet and use a smaller drill bit on it :shrug:

 

[creia]

BDG,
You only completed 2 of the 3 modifications! You need to do them ALL 3 of them for that engine to run correctly. Eliminate 1 of them and the engine wiill not run right.
1. Got rid of the OEM restrictive exhaust/muffler an install header- Done!
2. Re jetted the carb to a larger jet- Done!
3. Get rid of the OEM restrictive air cleaner and install a free-flow air filter- NOT DONE!
Michael

 

[BDG]

Thanks for the quick reply guys!! Yes i would just buy another jet as those are cheap however the stock jet was stuck inside! So i just drilled it out as it was still in the carb.. I made sure to clean it thoroughly before putting it back on the engine. Will definitely look into the PVC pipe though for sure! and yes i did try to remove the plastic cover on the airbox and while running it seemed to be a little bit better however at a stand still giving it revs it still blows black smoke therefore im assuming it's still running rich? Haven't been riding it long enough to get a clear read from the plug, looks normal. only rode for about 10 minutes.

 

[Newoldstock]

Its is not easy to drill a jet and I am willing to bet you went a little over size in your attempt.

I have a trick:
I use a very small high speed drill press and hold the jet in the chuck while I line up and centre the bit in a vice.
This ensures the hole is centre and plumb ( but its only has good as your set up time )
Start smaller than you need and work your way up.

Time to get serious and do things right.
Remove all the governor and buy the correct parts for safety.
Check Ebay for a steel flywheel like this
These are as cheap as they come and safe.
Billet Steel Racing GoKart Flywheel | eBay

You better find out what engine you have!
The powerfist 208 uses a different piston and rod than the stock clone.
They don't even make a billet rod for it so that means you will need to buy a predator piston and a +.020 Honda rod
Try and find a GX160 head head ( a real Honda head ) and some springs for a Honda G200 ( also known as the 18 pound spring set ).

Advance you timing to 25 btdc and check with a timing light ( do not guess )

A simpler carb will help.
If you have welder and some pipe you can hobble up a cheap and dirty intake and use the carb off a Tecumseh snow blower.
This is bigger and adjustable so no more need to mess with jets.

Start saving your money to do this right or your summer riding will be very short.
If you get all this done stop right there.
You will have a fine engine that will be fun to ride, your not racing so avoid the silly expensive stuff.