Eagler's Nest

Airframes => Single Seaters => XL => Topic started by: Mrbill on September 10, 2022, 04:43:46 PM

Title: Propeller Position Hummel 45
Post by: Mrbill on September 10, 2022, 04:43:46 PM
On the Hummel 45 what should the propeller position be in relation to top dead center?  I have replaced my prop with a GSC 58x22 and I'm getting pretty good shaking.  Right now I have it at the 10:00 - 4:00.  I've seen posts on other sites which were probably for a 4-cylinder (counter clockwise rotation I assume) and they recommend the 2:00 - 8:00 position for hand propping.  Any help would be appreciated. 
Thanks,
Title: Re: Propeller Position Hummel 45
Post by: CHARLES DEBOER on September 10, 2022, 10:15:39 PM
The prop is at 10 and 4 at the start of the compression stroke.  Top dead center is a mark on the prop hub when aligned with the seam of the split case.
Title: Re: Propeller Position Hummel 45
Post by: Mrbill on September 11, 2022, 05:43:32 PM
Thanks Charles.  I've reset my prop, but I'm still getting some shaking.  I have the wings off right now and was just wondering if I have them on do you think it will dampen the shaking?  I do have front starter on it as well.
Title: Re: Propeller Position Hummel 45
Post by: CHARLES DEBOER on September 11, 2022, 09:45:10 PM
No, the wings won't change the engine vibration.  Check the carburator slides to make sure they are synchronized, (open and closed the same amount) then adjust idle screws.  I am assuming your Hummel 45 came with duel Mikuni carbs.
SimplePortal 2.3.7 © 2008-2025, SimplePortal