I have a four year old mantis tiller with a two stroke single cylinder engine with a ZAMA diaphragm model C1U type carburetor. After using the tiller for a few hours this week the gas supply cut off. I removed the carburetor and using my compressor blew out all openings and took the gas filter off as it appeared to be dirty. After re-assmbly I attempted to start the tiller, however now it started to flood the engine wetting the spark plug which is new. After letting the tiller sit over night with the spark plug out and purging the combustion chamber I re-installed the spark plug, put the ingnition switch to on and tried to start the tiller without using the bubble purge or the choke. The engine started with on pull of the cord ran for about ten seconds and stopped. I took the spark plug out and it was wet with gas. I bought a carburetor kit from Mantis and a new gas filter and installed both after cleaning the carburetor throughly with gum out. The problem still existed. I once again cleaned the spark plug and after purging the combustion chamber and cleanin the muffler system, I re-installed the spark plug, cut off the gas supply to the carburetor and restarted the tiller it ran great with the gas that was still in the carburetor, I cut off the ignition switch, cut it back on and restarted the engine it ran for a few seconds until the gas ran out. I unclamped the gas line, let in a small amount of gas to the carburetor then reclamped the gas line, dried off the spark plug, started the engine, it started right up and as it ran I opened the fuel line and it flooded out immediately putting me back to square one. Only two items were not replaced, the Main Check Valve Nozzle in the caerburetor, and the Check Valve that comes out of the gas tank. This really has me stumped. HELP, Bob
If you installed the new metering arm that came with the carb, reinstall the old one unless it was very worn as it has the proper height setting. Have a good one. Geo
Thanks for the input Geo, I've tried that also to no avail. I'm going to be gone for about a week, but if anyone has any further input please post it and I'll check when I get back on the 13th. Thanks Bob
Is the spring under the metering arm still in place? If not, this is the problem. If this isn't the problem (the spring is there), did you replace the needle?
I'm also having similar problems w/ my mantis tiller. Mine is several years older, but I replace the carb a year ago. It's also a zama C1U type carb. It worked the first time I put the carb on. The second time it ran for about 15 mins and it hasn't run since. Does your puke gas out from under the gas cap?
Originally Posted by cheese
Is the spring under the metering arm still in place? If not, this is the problem. If this isn't the problem (the spring is there), did you replace the needle?
Cheese, I replace everything in the carb with a new kit. That included a new spring, Inlet Needle, Metering Lever, Arm Pin, new Diaphragms and Gaskets. The parts list in the users manual lists a Main Check Valve Nozzle, but I don't believe that a replaceable part. Bob
Finelly found out the problem with the carburetor and tiller is doing fine.
What was the problem?
Yeah, what'd you find wrong?
Originally Posted by bobwhite1
Finelly found out the problem with the carburetor and tiller is doing fine.
what did u discover to be wrong w/mantis carb?
Originally Posted by americanhorse
what did u discover to be wrong w/mantis carb?
I have a 1994 mantis that has set up for about 5 or 6 yrs. and i am having the same kind of problem. I have cleaned the carb, put in a kit but i am having the short run, flooding carb, wet plug, and oil coming out of the exhaust. I would love to what you found was the problem.
Sorry I haven't posted lately, just got back on the computer. The problem was corrected simply by adujusting the high and low needles. Most carbs are turned out about 1 and 1/4 turns but this one with the plastic restricter only turn out 1/4 turn for the high and low, once I did this it started right up and all I did was adjust the high side a hair richer and its been running great ever since. Hope this helps someone out there, take care, Bob
Tags: mantis, tiller, carburetor, problems, spark plug, this problem, Check Valve, found problem, Originally Posted, carburetor tiller, carburetor tiller doing
