Webra T4-40 A Look Inside 

I always like being able to see inside.

Glad there was no damage whatsoever inside the engine, at least that's out of the way as a possibility. Really wishing you better luck on your next attempt David ;) Regards Harry

6:23 I had that happen with an HP 12 I bought from my LHS for peanuts. I tried for a couple hours to get it to run and it would barely even pop. So, in a fit of frustration, it got chucked in my 'engine drawer' and forgotten about for a couple yaers. Then I get my hands on a SIG Tri-Star kit which calls for an engine of that size, and because the HP 12's snout unbolts, I can easily retime it to run in reverse which opens up a TON of prop options on a pusher plane like that. So, I retime it for reverse rotation, mount it on the stand, go back outside. FIFTH FLIP STARTS UP RUNS LIKE A BLOODY OS! I can't tell you why that's how things transpired but it earned a permanent home on the back of that 10-size canard. On this Webra...I loathe timing belts and I imagine getting replacements for these is nearly impossible, so I would never fly one, but I would like to have one of these Webra 4-strokes in my collection just to say I own one.

I wonder if the belt should be installed during reassembling the head, i.e., put the belt on and then bolt down the head. I don't actually know. It just seems worth a try if you ever find yourself doing it again.

Interesting engine for sure. Glad there were no grind marks. Headed to the short!

Hey Dave. Respect, you kept your cool. Some days best to leave it in the box ( the engine that is). Thought only diesels played hide and seek. I heard calming music, wind chimes, song birds, even the lonesome locomotive! Rotary valve. Wow. Please do a vid on that. Are you sure the plug is OK? As you say, no reason it shouldnt fire at least. Bests fromdieselland john

It's good to see there is no evidence of grinding or anything. Really interesting engineering.

Hi David, While watching the video, I think I see a mark on the aluminum pulley that may be a timing mark. It appears to be at the 8 o'clock position when you replaced the timing belt with the crankshaft at TDC.

Dave, looking at how far the OS glow plug extends into the compression chamber, maybe a short thread plug will produce better combustion? Just guessing. Dang, putting the belt on and while retaining the rotation of the crank and the rotary valve seems way to difficult. I suppose Weber’s had a tool that makes this so much easier. Looking forward to the next attempt.

Interesting. I have the side mounted carb version and the marks are more obvious.

You don't have to run a four stroke plug. The F plug is a great plug though as I run it in all my .40 and up glow engines two or four stroke.

I would have liked to see if the rotary valve was not rotated 180 degr. so that the intake port had bomce the exhaust-port.... instead of trusting on how it was put together from the factory.

Timing. Imagine that.