Heymow - Lawnmower Racing Forum

Engine Help => Briggs OHV & Vanguard => Topic started by: silveradoboy on April 20, 2017, 12:53:57 pm

Title: 28 vs 31 blocks
Post by: silveradoboy on April 20, 2017, 12:53:57 pm
i have a 31a607-0741-b2 15.5hp ohv briggs engine and im trying to find a walbro lmt carb to put on it but cant figure out if one from a 28 block would fit. i dont care about the solenoid on the bottom of the carb because i plan to wire it out anyway, im trying to get away from the stupid nikki that is on the engine.

would a 698171 carb from ec fit? everytime i look at their site i shows it being a 28 block carb and not the 31 block.

and what is the biggest difference between the 2 blocks besides one being older than the other? will engine covers fit and internals be the same?

silveradoboy
Title: Re: 28 vs 31 blocks
Post by: EUBANK RACING on April 20, 2017, 03:02:20 pm
Basically to keep it simple, everything is the same except the bore, no difference in carbs
Title: Re: 28 vs 31 blocks
Post by: silveradoboy on April 20, 2017, 06:12:09 pm
Thanks, I appreciate the help

silveradoboy
Title: Re: 28 vs 31 blocks
Post by: BIG AL 202 on April 21, 2017, 12:45:28 pm
AS LONG AS ITS NOT AVS!
Title: Re: 28 vs 31 blocks
Post by: silveradoboy on April 21, 2017, 08:20:16 pm
What does the difference of avs mean? I have the avs block does that make a difference?

silveradoboy
Title: Re: 28 vs 31 blocks
Post by: nip 19 on April 21, 2017, 10:54:55 pm
Avs motors run different  size cranks and balancers  than non avs. Typically they won't take the beating in a stock form that a non avs will but both motors can be built to run strong with the right parts.   Do a search . Tons of info on here about those motors.
Title: Re: 28 vs 31 blocks
Post by: silveradoboy on April 22, 2017, 08:26:24 am
I always wondered about the difference. Thanks to help guys ill do some searching later.

Do y'all know if people cut and modify the engine cover to run a velocity stack and pod filter or do they run a 28 block cover?

silveradoboy
Title: Re: 28 vs 31 blocks
Post by: Mickey mower makin on June 14, 2017, 04:00:11 am
Basically to keep it simple, everything is the same except the bore, no difference in carbs
[/queote] in that case will a flywheel for a 31 or 28 interchange with each other?