29cc DDM

[badboy2]

Just took the plug out after running it again in the front yard and tuning it a bit and she does the same thing. Took the guts out of the fuel cap except the rubber dome and there was no pressure inside. The spark plug looked like a number 11 or 19 now but still no power. I know the fuel lines are correct as well since I changed them and the glunk is at the bottom. I am stumped now. does this mean it's a motor issue?

what about trying a different carb?

 

[C-Mac]

would the one on the stock motor?

 

[DemonRC]

Here's what I would do. Since it's not obvious what the problem is, you need to start eliminating possibilities. You've aready checked your fuel line and fuel tank so I would start with the carb. While it's idling spray WD40 on it and check for leaks. I've had plenty of leaks around the throttle shaft which caused problems like you are describing. AFter that check the engine:


1) Check your head gasket to make sure it's intact. You need to remove the fan shroud to check the back.


2) Since you got the engine 1/2 apart, pop the head and see if your cylinder walls are scratched up.


3) Wobble the clutch and flywheel back and forth to see if there's any play. Play in the flywheel and/or clutch would indicate a bad bearing which would kill the crank seals and cause the engine to run bad.


4) Examine you crankcase gasket to make sure it's intact.

 

[C-Mac]

I swapped carbs and thats not the issue. I think when the pull start broke something else must have since it makes a ticking noise. I will have to pull the motor apart and see what's up like Cat has suggested. Details of my findings to follow

 

[C-Mac]

Took the motor out and the cover off the flywheel. I don't see bearing or gasket damage although I am far from a pro on these motors and just seem to be lost. I can't seem to pull the flywheel off and check the rest. Is there a small engine repair shop in Surrey BC that could help me that won't break the bank?

 

[kryptonite]

ya, i actually use the gear mount bolts too. you can "push" the flywheel off with them. if the bearings/seal will be bad they will go on the clutch side first. like moo said. if the crank shaft wiggles up or down then the bearings are bad. also look for black dust from the rubber seals.

 

[C-Mac]

This may be nothing at all but does the fuel tubbing have to be the exact same size in diameter as the stock tubing? As well there was a metal bracket on the carb that I took off, kind of a spacer, could that not being there affect the performance? Today when I ran it I had filled the tank and as it ran I could see gas spueing from the hole in the cap. I take it that means to much pressure is building up in the tank?

 

[DemonRC]

I have gas coming out my fuel cap all the time when it's full. Don't worry too much about it.

 

[C-Mac]

took the 29cc out and replaced it wit hte old 23cc and it runs perfect so I can only assume it's the motor. Still can't get the flywheel off but like I was saying when I run the 29cc it makes a ticking noise so something isn't right.

 

[max 1]

check your sqish clearence .sounds like the piston hiting the top of the head.if so it may pincth the ring in the grove.pull the head of and check to see if the ring is free in the ring grove .

 

[C-Mac]

I took the head off the motor so the piston was free and the piston ring seemed fine according to my mechanic neighbor

 

[C-Mac]

I bought the motor about a year ago when I got my MT but I never put it in till about 3 weeks ago. I broke it in at idle for about 1/4 tank then just did circles at about 1/3 to half speed for another half tank. I'lll get some pics and post them.