B&M Belt Tension ??????

[DansBlown73Nordic]

Can anyone tell me how to adjust the belt tension on my 250 Blower? It has this lock nut on one side. On the other side is a bolt.
Should the belt kinda flop around a little bit? Like when I blip the throttle it makes a slack spot in the belt?

[Infomaniac]

Serpentine belt? If so this is it.
You should take the lock nut off and put a cotter pin in the hole. The idler needs to be able to float in and out. The nut is only there so you can draw in the idler to get the belt off. If you leave the nut on it might not ge able to float enough. The cotter pin keeps the idler from spitting out if the belt comes off.

[Jordy]

Hey Info,
Since we're on the subject of blower belts, what kind of tension should be on the belt? I've got an 8:71 and a superchiller on a BBC. I just had it running on the trailer after changing spark plugs, fuel filters and fuel pressure regulator and there was quite a bit of play in the belt when it was idling. I'd say about an inch of deflection when it's shut off.
I'm kinda new to the blower thing and figured I'd ask before I tightened it up and something broke.

[Blown 472]

Originally posted by jordanpaulk
Hey Info,
Since we're on the subject of blower belts, what kind of tension should be on the belt? I've got an 8:71 and a superchiller on a BBC. I just had it running on the trailer after changing spark plugs, fuel filters and fuel pressure regulator and there was quite a bit of play in the belt when it was idling. I'd say about an inch of deflection when it's shut off.
I'm kinda new to the blower thing and figured I'd ask before I tightened it up and something broke.
I was always told that when everything is hot and expanded that you should be able to grab the idler pulley and move it and have the same drag as lashing valves.

[DansBlown73Nordic]

Im not sure I follow you. I do realize the nut is used to remove the belt. You are saying to remove the nut and drill a hole in the stud and put in a cotter pin?

[Infomaniac]

Dan - all of them I have seen have a hole already right at the end of the threads. Any pictures?
Jordy - an inch of deflection is OK but when everything is dead cold. When it heats up most of it will go away.

[Jordy]

Thanks Info. I'll check it out when I'm out on the water and it has some heat in it. You rock as usual.