cy 26 cc lack of power

[mooman007uk]

You don't want to run it with any needles all the way in, it will lean seize, it should be tuned to run rich if anything.....any bogging is a sign of a lean mixture

I think you may have misunderstood me, the idle adjusting screw is the one on the side with a phillips head, tapered tip and spring that adjusts the position of the butterfly in the card at idle not the L mixture screw which i said was 1 1/4 turns out.

if you run your h or l needle too lean by 1/4 turn or more the engine will bog due to lack of fuel, you'll have a high idle but as soon as you nail the th it'll starve for fuel ....on the h mixture it'll start to starve at the high end of the rev range like it's running out of gas. lean bog can be due to both needle settings that are way off or an air leak, not just an air leak.
i agree that on the top end if it's lean but not way off the motor will still rev hard, then get hot and seize if you keep running it.
2 types of bog down that sound slightly different...lean sounds like "war" when you say it and rich cackles a bit more

 

[Largescalebuilder]

The bogging is at the beginning when he give the gas. That is where the problem is. You don't get bogging at high speed. It will just reve up too lean. I don't think you even know what bogging is. Even with a leam low setting it won't bog down. It will jrust reve up and stop. Bogging is when the engine is not getting enough fuel at the low with the factory settings and the engine is trying to engauge the clutch while advancing the throttle at low speed. Toooooo much air is beign sucked in hence the booging sond.Iit disapears when the the throttle advances to high. It is always around the carb. It may be a bad gasket or the filter sceen inside is blocked. how full is the primer bulb? That is a clear indicator to the problem. If it is near full then the carb is ok. But if it is half full ar less the you found the problem. :w00t:

 

[motorman]

Bogging is a sign of an air leak. Not lean settings. The engine will just rev up higher if you set it too lean. the Top end has nothing to do with bogging. Bogging only happens with low speed settings. :lol: Low setting should be 1-1/2 +- 1/4 turn High 1-3/4 +-1/4 turn.

those needles settings are way to rich. i live at sea level and my needles run leaner than this.

I think you may have misunderstood me, the idle adjusting screw is the one on the side with a phillips head, tapered tip and spring that adjusts the position of the butterfly in the card at idle not the L mixture screw which i said was 1 1/4 turns out.


if you run your h or l needle too lean by 1/4 turn or more the engine will bog due to lack of fuel, you'll have a high idle but as soon as you nail the th it'll starve for fuel ....on the h mixture it'll start to starve at the high end of the rev range like it's running out of gas. lean bog can be due to both needle settings that are way off or an air leak, not just an air leak.
i agree that on the top end if it's lean but not way off the motor will still rev hard, then get hot and seize if you keep running it.
2 types of bog down that sound slightly different...lean sounds like "war" when you say it and rich cackles a bit more

i understood what you were saying. you are completely right, if the needles are set to lean, it can bog and that is likley what is happening in most cases, or the carb is dirty/fouled, in need of rebuild. most of the time and airleak that is not very big will let the engine run, but run lean. if the airleak is large enough then the engine will not run or when throttle is applied the engine will die immediately. either way, all variables need checked.

The bogging is at the beginning when he give the gas. That is where the problem is. You don't get bogging at high speed. It will just reve up too lean. I don't think you even know what bogging is. Even with a leam low setting it won't bog down. It will jrust reve up and stop. Bogging is when the engine is not getting enough fuel at the low with the factory settings and the engine is trying to engauge the clutch while advancing the throttle at low speed. Toooooo much air is beign sucked in hence the booging sond.Iit disapears when the the throttle advances to high. It is always around the carb. It may be a bad gasket or the filter sceen inside is blocked. how full is the primer bulb? That is a clear indicator to the problem. If it is near full then the carb is ok. But if it is half full ar less the you found the problem. :w00t:

im not sure if you know what bog means! i think mooman knows. it will bog with a lean low or lean high needle, quicker with the low needle than the high though. usually if the user sets his high to lean it is just enough that he toasts the motor after a gallon or so(prematurely), but it can be set lean enough that it will bog. the low though, if set to lean and the user is not experienced and thinks he will get better response by going in on the needle he can get to the point that the engine will literally cut out/bog. that is what bogging is. bogging from rich condition is bogging, but normally the engine will run, just at a lesser rpm. so, there are two types of bogging and it can be caused from a lean high or low needle and a airleak.

i do agree with the comment on the carb. a lot of times the carb gets over looked for a long time till finally the user just changes everything. although, your comment on the carb contradicts what you are saying about bogs. if the carb was fouled and the engine was bogging then that would be from lean fuel mixture, not an airleak.