A strange Stuart MTB1

[Sanjay F]

Well done everyone, your detective diagnostic skills have got to the bottom of the issue.......

Video 1 - crankshaft running smoothly without pistons
Video 2 - crankshaft running smoothly with pistons - no rings/packing

So tomorrow I'll have to reassemble and see what effect having no rings/packing will have. Hopefully, I can lower the pressure and not so much will blow past the pistons?

BTW - broke another ring, so won't be putting them back anytime soon 

https://youtube.com/shorts/ZLMxfceVfks?feature=share

https://youtube.com/shorts/U0uMUriFxFw?feature=share

[crueby]

Getting close to the root cause!


One thing that I  noticed when watching the video with pistons but no rings, is that the bottom end of the piston appears to come farther out of the bore than it did in the earlier video with them in place. Maybe a step or taper in the bore keeping the piston from full travel up or down? I'm  sure you'll  track it down!

[Sanjay F]

WE did it!  Another collective success for MEM 

In the beginning I was doubtful this little engine would ever run, but the process of slowly eliminating each of the issues has paid off, thank you all for your guidance and encouraging me to keep going!

https://www.youtube.com/shorts/vKl2SnpuB-c

[crueby]

Awesome!   




What was the final cause of the st8cky spot?

[Sanjay F]

I think the main issue for the tightness was the rings, and as you mentioned it looked like the pistons were coming down futher after they were removed, which they were - in fact this increased an existing problem of the conrod caps striking the inside of the crankcase.

I didn't have to do anything more to solve that than fractionally moved the position of crankshaft and lock it in place using the flywheel and cam plate; this in turn moved the conrods across slightly and stopped the them striking the inside of the cover - that explains why it was locking at TDC and BDC alternately?

[Jasonb]

A good outcome. What's next?

[Admiral_dk]

Good to see it Run 

Per     

[Dave Otto]

I get video unavailable, do these YouTube shorts have an expiration?

Dave

[crueby]

I get video unavailable, do these YouTube shorts have an expiration?

Dave

Just opened fine here. 

[Dave Otto]

I bet it is an issue with Firefox, it doesn't play well with YouTube. I think they kind of hate each other, but google hates everything that isn't google.

Dave

[Dave Otto]

Yep I was able to open it just fine in Duck Duck Go.
Congrats on getting it sorted and running Sanjay!

Dave

[crueby]

I bet it is an issue with Firefox, it doesn't play well with YouTube. I think they kind of hate each other, but google hates everything that isn't google.

Dave

I use firefox, and have no problems with youtube at all. There must be some security or adblocker setting you have that is fighting with youtube.

[Dave Otto]

Maybe Malware Bytes I have had issues with it in the past, I thought that I had done something in the past to allow YouTube to run. I will look into it.

Thanks
Dave

[Sanjay F]

How strange - I've haven't heard of any issues with Youtube before, but glad its sorted and you watched it, thanks

[Michael S.]

A pleasant experience. The engine runs well.