Farmboy engine

[Boot]

I'm having trouble getting the engine to run. It seems as though I'm losing compression back through the intake valve. I have tried seating it with course grinding compound and also real fine compound. Neither has worked. What else could be defeating my efforts. I have noticed if I run the flywheels counter clock wise it puffs more than clockwise from the governor side.

 

[Engine maker]

Boot, you have to seal the compression leaks. I sent you an e mail.

Jim G

 

[Geartooth]

I am currently building Farm Boy #510. I would love to see pictures of your build.

 

[Boot]

I don't know if I got it right,but here's a picture of engine. Jim I don't know where your email went but I will pull the head off and redo the valves again. I'm going to try putting a rubber tube on the end of valve and using that to grind them in. I thought someone else would have an idea that is why I asked. Boot

 

[Boot]

Hello Geartooth: It looks like you did a great job of machining you engine. You're not far away from firing it up. I hope you have done a better job of
sealing the valves than I have. I'm getting to wits end on it. I wouldn't think that it would be that critical ,but it must be. Or I wouldn't be getting air back to my gas tank when I spin the engine. I even pressed the valve cages out and re -machined them and the valves and had no luck with them. I'll give them one more grind before I give up. Next I'll have to make new valves and change the angle from 45°s to 44°s and see if that helps.
Good luck with yours. Boot

 

[10K Pete]

Good looking engines guys!! A big warning on lapping valves: Most newbies seem to use lapping abrasives that are far too coarse. If you're
using anything coarser than, say, Brasso for the final fit then you're really
only making big giant gouges on the sealing surfaces. Use a magnifier, at
least 5x, and look at what's there. A 10x is better.

Pete

 

[Boot]

Thanks Pete:
I'll have a look at them in the morning. I did use too course stuff the first time. Now I have a mostly liquid stuff and you're right even that seems pretty course. I'll let you know tomorrow. I hope I don't have to use brasso because I don't have any. Maybe tooth paste will do it. Boot