Runtong Carb won't run right

Joined
Jun 29, 2017
Messages
63
Hello all,

I have a runtong carb (dellorto knockoff) that I can't seen to get tuned right. I am running a #63 sized jet and I am afraid to go down anymore and I am at a 1100 ft elevation. If I accelerate rapidly it four strokes but if I accelerate lightly it is just fine. Once I go over 20 mph it'll start four stroking as well. I am running an NGK B6HS, and I have an RSE High Compression head as well. It four stroked a lot more with the stock head and improved a tiny bit after I put the high compression head on. The spark plug is tan colored and I don't want to make the low end to lean. I have the EPA certified Flying Horse 66cc engine. I am currently running a 100:1 ratio with opti-2 and I have 410 miles on it so far.

I am about ready to put on the NT carb I have in the garage. What else should I try? I have checked everywhere on the engine for leaks and it is just fine.
 


U

User 27079

Guest
Use SealAll and put some around the part of the intake that goes into the carb....i had to put some inside that collar to fill the two cracks.
Then place some around the threaded part that goes into the plastic part on top of the RT carb.
Check for leaks elsewhere around the carb as well.
SealAll is your friend ;)

I've found that the RT carbs are not really true on roundness in the throat..anyway...so it made the throat to intake fit a bit egg shaped which SealAll fixed, i had the same probs..am at around 1200 feet above sea level.
Also check that the small rubber gasket for the bowl is proper.

Ride Safe! :)
 
Joined
Jun 29, 2017
Messages
63
I added some motoseal gasket maker to the inside of the carb as there was a slight crack in the plastic seal and since its gasoline resistant it shouldn't cause a problem. I replaced the stock cdi with an aftermarket supercharge cdi and put in an NGK BPR6HIX Iridium plug. I dropped the jet to a #62 and so far no blogging at all and I can twist it to full throttle and it just climbs with no four stroking. I went from a top speed of 23 mph to 29 mph. Nice tan color on the spark plug as well. Thank you everyone!
 
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