I bought four of the 26cc blower engines advertized on EBAY.
I have not been able to remove the nut that holds the fly wheel on. Is that a left hand thread?
Here is two pictures of the engine with the shroud removed

That engine sure looks like a Mac blower engine. It should not be L.H. Threads. Go to the Yard man engine site and look up MC290...its the same as Mac MB290. Place flywheel in a vise and use a six side socket. May have to heat a little with propane torch to loosen locktite. Capt,n

I have 18 of those engines..The nut comes off easily with my 3/8 air wrench..Thread is 8mm x 1.0 pitch, right hand....The Chinese Loctite material really holds....

RCIGN1: I have a air impack 1/2 drive...never thought of trying it. Ya shure want the wrench in the right direction with mine...its a killer!!!! That same engine is one tough engine. I run the puddin out of it in my leaf blower...like several tanks right in a row. She needed to be richen-ed up a tad...now she screams. It works so good in leaf blower I got to keep it there. It out does any other leaf blowers I got...including the 30cc Homelite. Best Regards Capt,n

This ia a photo of when I had the Mb290 out of blower. Capt,n

Do you use the stock Carb? I note there is no adjustable jets on it.

On my blower the stock carb is ok, but on a airplane I would go walbro I think! Capt,n

Try heating the nut with a torch. Those engines have a green Chinese threadlocker on just about everything. It's an M8 X 1 right hand thread.

So are these engines good???

YES...good...they start real easy by hand...idle real good...good RPM for stock...for the money...you cannot beat them. Capt,n