She's Lost Her Power, Captain!

[Mountainman]

takes a good thumb to do that !!

You dont need a compression guage for a small 1 cylinder 2 stroke engine! just put your thumb over the spark plug hole and if theres a strong pulse of air then compression is fine. your thumb is a compression tool.

are we saying here that one can tell the difference

between 50 psi and 80 psi ??

takes a good thumb to do that !!

many here can do the thumb THING
but also -- many others will not be able to

a thumb is to be taken much care of -- used often as we ride that THING

 

[fylerc1]

Another possibility I've run into, and completely different than these other responses is to adjust your clutch. Mine gets loose once in a while and appears to lose power when it's really just partially slipping. Since you've got so many miles on the beast, it's possible your pads have warn down, requiring a tightening of your butterfly(star) bolt. It's harmless enough to check at least. Remove the screws over the clutch plate, remove the one screw holding the butterfly bolt in place and tighten it up (I use a hammer and a nail set, but whatever works). If this is the problem, it could be fixed in minutes, if not I'm at a loss.

 

[Pablo]

Good pornt on clutch slippage.

 

[klassard]

I tried my thumb and there seems to be a puff of air but not much. Although, I've never stuck my thumb in an engine before so I'm not sure what constitutes good pressure. On the bright side, there is a Sears and a Harbor Freight nearby.

Checked the clutch and it is engaging well.

Thanks again for the responses! I'll grab a compression tester this week and see how that goes.

Come to think of it, I did notice a little oily stuff around the base of the cooling fins. I wonder if that means the gasket is not sealed.

 

[Pablo]

What are your head nuts torqued to?

 

[hill climber]

your thunb has a preasure gauge? were did you get that installed? i need 1 of those. with low compression your motor will run but poorly. get a compresion tester and check it.if the head is leaking you should see black goo coming from the head gasket area.

 

[MotorMac]

thumb

Sorry, I guess I need to explain more clearly. By sealing your thumb over the sparkplug hole you can guage if you have good compression or not, when you turn over the engine the pressure pulse from the piston should be strong enough to lift your thumb off for a split second, if it does not lift your thumb off you have an internal ring, head gasket or piston problem. Yes I can gauge the difference between cylinders with my thumb with a multi cylinder engine but I do use a guage for that.
The thumb test is just to determine if you have compression or not.
By the way does anyone know what the compression PSI is supposed to be for these small H.T engines?

 

[hill climber]

ok, so i just went out to the garage to check the compression on one of my ht's. the motor is a live fast motors 55+cc budget kit. the motor has about 20 miles on it and is stock other than port matching. removed the plug and rested it on the head, insalled compression gauge and rotaited rear tire,turned the motor over about 10 times. throttle was in the idle position. gauge reading was 105psi. gonna go check the other one now.i wanna know.
checked the other motor, it has had the head milled and a thinner head gasket installed, totaling about .045 inch the compresion read 160psi. this motor has over 1000 miles on it and over 400 since the work was done. 1000 miles, 160 psi and going strong.

 

[Mountainman]

hey MotorMac
not to get you wrong there
knew exactly what you were talking about
the old thumb in the hole test
you are so right -- good THING to do
just to get a rough idea

hey hill climber
excellent
now klassard has someTHING to shot for
thanks for running out there for us -- checking yours

hey klassard
guessing here
because your engine is not in a compleat failure mode

if your engine is under 90 psi -- slightly worn and torn
" " " " " 60 " -- gone baby gone

if you are 90 psi or above -- not the problem

ride that THING

 

[klassard]

Well Pablo, I'm not sure what my nuts are torqued to these days. I think the only time I've ever really torqued my nuts was when I landed wrong off a BMX ramp, but that was a long time ago. In all seriousness though, I don't even have a torque wrench so I'll probably have to pick one up when I get the pressure gauge.

I do have black goo around the gasket so that might be part of the problem. I'm definitely going to grab a pressure gauge from Harbor Freight though.

Thanks again for all the help, everybody!