Im putting together a 60 size Sbach - and having trouble getting the right clearance between the cowl and spinner. So far Ive counter sunk the mount bolt that sits behind the carb, but wasnt enough. ive also tried rotation the carb, but wouldn't help either Would it be ok if I moved the mount bolt to where the blue tape is(see pic), and cut off the top 1/2" on the mount to make room for the carb? Would this cause any issues? This is the only bolt I would need to modify location on.

Thanks

Hey Ro nice work on explaining and illustrating your problem. Hmm fourstrokes can be a hugh pain in the butt especially if they are oversize huh?

Ok three is nothing that says the bolt pattern has to be square, in fact Dave Brown mounts (my favorites) are intentionally drilled already with none square bolt pattern to provide for a greater number of options. Of course one size does not fit all, that's just not possible. Anyway back to your problem I see no problem what so ever with what you propose and believe it will work just fine. I have done many similar mods to filled mounts and never any real negative results.

Perhaps there may be a slight greater chance of breaking the engine mount in a severe crash but in my book that is a goo thing and less change of damage to the engine

John

Thank you John! Ive actually used the DB mounts in the past and are my favorites as well. Much easier being a one piece. Either way, As Im shooting for really light here, a DB wouldn't be best for me this time around.

As far as the mount breaking in a crash.... This plane is built so light, there probably wouldn't be much left after a crash like you describe anyway, so the mount would be the least of my problems. LOL.

Thanks for assuring me the location change will work. I actually was looking at a DB mount when thinking about this question, and figured square pattern wasnt a requirement. I just wasnt sure if placing the mount bolt so close to the thrust line (for whatever reason) would have been an issue.

Thanks again!