I've run a harbor freight OHV honda GX200 clone on my snowblower about two years now. Getting it out of fall storage I found a leak on the fuel shutoff. A bit disappointing. But a new carb off ebay came to my door for $15. It even allows adjustments like slow idle speed that the OE carb ("designed in japan"
) had capped off.
Now that the motor is out of warranty, and I had a spare carb to play with, I figured I'd rejet it to take care of a WOT surge. A little choke fixed that surge and I secretly suspect this engine was designed for pure gas, not E10. It was popping out the muffler when I slammed the throttle shut and generally acting lean.
Anyway, I got a cheapo mini drill bit set off amazon. Didn't need anything special as I'm only drilling through soft brass. Extracted my spare main jet from the broken carb and went to work. Stock is .028 inches or actually slightly smaller as .028 in was a no-go. (chart of drill sizes)
I had time. My drill bit kit came with an x-acto knife holder so I didn't and shouldn't use power. Just worked it with my hands. Went up three sizes to a number 67 bit or .032 inches. Just did each size sequentially so I wouldn't overload a bit and break it. It seems like a lot more fuel if you do the math, area= pi r squared, but probably is not in practice, for reasons I don't comprehend. Many go-karters are running .037 to .040 inches but have made other modifications to the carb or exhaust.
My only other mod, which is reversible, is running without an air filter. Snowblowers don't generally use them and this motor is a universal replacement for all sorts of OPE. An air filter acts as a choke. I figure I could use the power. The plastic filter cover will keep snow and water out of the carb. I still have the filter and put it on for giggles and honestly didn't notice much difference.
Anyway it runs much better now. I don't want to "overshoot" my jetting and wish I hadn't made that last hole bigger... even though I have a spare stock jet. I can take it off choke after 5-10 seconds of running, used to have to do a row of snow first.
The one thing I wish I could figure out is the idle jetting. Reading online, I could pick out a plug then the jet would be there. My chonda carb, which is my experimenting/ proof of concept/ go ahead and wreck it had a very thick plug then no jet to be found. Just four tiny holes in the casting near the closed throttle blade. I guess they cheapened the design. I'm not one to spend much time at idle, but it would be nice to richen this up so I didn't have to choke it for a warm restart.
Anyway, I'm throwing my experience out there as most 6.5hp clone modifiers want to go whole hog for performance while I just want it to run as it should without fuel diluting the oil or fouling plugs.
Now that the motor is out of warranty, and I had a spare carb to play with, I figured I'd rejet it to take care of a WOT surge. A little choke fixed that surge and I secretly suspect this engine was designed for pure gas, not E10. It was popping out the muffler when I slammed the throttle shut and generally acting lean.
Anyway, I got a cheapo mini drill bit set off amazon. Didn't need anything special as I'm only drilling through soft brass. Extracted my spare main jet from the broken carb and went to work. Stock is .028 inches or actually slightly smaller as .028 in was a no-go. (chart of drill sizes)
I had time. My drill bit kit came with an x-acto knife holder so I didn't and shouldn't use power. Just worked it with my hands. Went up three sizes to a number 67 bit or .032 inches. Just did each size sequentially so I wouldn't overload a bit and break it. It seems like a lot more fuel if you do the math, area= pi r squared, but probably is not in practice, for reasons I don't comprehend. Many go-karters are running .037 to .040 inches but have made other modifications to the carb or exhaust.
My only other mod, which is reversible, is running without an air filter. Snowblowers don't generally use them and this motor is a universal replacement for all sorts of OPE. An air filter acts as a choke. I figure I could use the power. The plastic filter cover will keep snow and water out of the carb. I still have the filter and put it on for giggles and honestly didn't notice much difference.
Anyway it runs much better now. I don't want to "overshoot" my jetting and wish I hadn't made that last hole bigger... even though I have a spare stock jet. I can take it off choke after 5-10 seconds of running, used to have to do a row of snow first.
The one thing I wish I could figure out is the idle jetting. Reading online, I could pick out a plug then the jet would be there. My chonda carb, which is my experimenting/ proof of concept/ go ahead and wreck it had a very thick plug then no jet to be found. Just four tiny holes in the casting near the closed throttle blade. I guess they cheapened the design. I'm not one to spend much time at idle, but it would be nice to richen this up so I didn't have to choke it for a warm restart.
Anyway, I'm throwing my experience out there as most 6.5hp clone modifiers want to go whole hog for performance while I just want it to run as it should without fuel diluting the oil or fouling plugs.
