Lebus1

Hi, I am having difficulty getting enough rpms out of my weedwacker Homelite 26cc. With stock muffler and new carb, pulling a 10X6 prop I can't get over 5500 rpm. I have been told that weed trimmer motors are engineered to only run that speed to prevent injury to weed trimmer operators if the drive cable snaps. If that is true then my quest is finished and I need to buy a 30 or 50cc gas engine. Any thoughts would be appreciated. DB

alan0899

G'day Mate,
I'm sure 10x6 was a typo, what size prop are you running?

Cheers

w8ye

My Feedback: (16)

18 X 8 is the usual prop for the old homelite 25 and a stock engine with a open muffler and 11mm carb turns close to 7000 rpm

I don't bknow anything about the Chinese 26cc engine

av8tor1977

My Feedback: (6)

Sure you do W8YE. You just don't want to "go there", and I don't blame you!! Tee hee...

AV8TOR

Lebus1

I did try the 18X8, 18X4, 18X10. I could never get over 5000 so I strapped on the small prop to see if it could wind up on that. I had the compression tested (70#) and crank pressure tested for leaks(none found). It sounds like I'm off to China for a cheap 50cc.

av8tor1977

My Feedback: (6)

70 lbs. is quite low compression. How does the piston and rings look when looking into the exhaust port? If the piston is not scored, you can purchase a Frank Bowman ring for it for $11.00. That will make a world of difference in how it starts, runs and handles, and the power. It will not however, come anywhere near the power of a 50cc engine of course.

AV8TOR

w8ye

My Feedback: (16)

I have a couple of the old Homelite 30's as model engines and there is no problem in the power department. I also have a "25" that is in the "Bandit" weed eater form and it is going to stay a weed eater.

On Av8tor1977's recomendations I have mostly Echo yard tools.

av8tor1977

My Feedback: (6)

Yep, it's hard to beat an Echo. Stihl is very good too.

AV8TOR

w8ye

My Feedback: (16)

Getting back to the Homelite 26, there is something wrong with it.

Even if it had a ignition limiter, they are typically set at 7000 rpm

Even stock it should turn at least 7000 with the 10-6 prop.

We cannot hear it run. It may be just a mixture problem? Maybe a air leak? 

One thing is for sure and that is to be an effective model airplane or boat engine, it is going to need both a high speed and a low speed mixture control on the carburetor.

av8tor1977

My Feedback: (6)

Yes, it could have a carboned up exhaust, exhaust port, or other things wrong with it, but surely the compression is way low, as he posted, and that problem needs addressed.

You get much below 70 lbs. compression and they don't even want to start at all, much less run well.

AV8TOR

w8ye

My Feedback: (16)

+1

Texastbird

The stock muffler on my Homelite trimmer had a screen over the exhaust that is a spark arrestor. If this thing plugs just a little bit it will ruin the performance of the engine. It is easily removed if still there. You just have to take the muffler off to check.