Venting a primary with belt?

[[JP]]

Hi all...

so, on my mad dash to get the Pan ready for her trip over to Europe in 2 weeks time, someone told me the other day that the primary has to be vented??

First I ever heard of it. But then again my cone is open belt... haha and the genny is still on chain.

Anyway, I was told because it's a belt drive I need to vent the primary...

What are my options here?
I was thinking making some spacers for the bolts and set the cover off so there's a gap for air to go in?

would look stupid though...

holes underneath instead?
do I need to vent it?? really?



thanks!

[richbob]

I ran mine closed for over 10 years .0n finally breaking it was pretty filthy and oily.

[Thunderbird]

my only experience is with primo's run open on two pan's. But heat being a killer of belts if I had a setup like yours, do like the diamond primary cover, i'd be happy just to run without the derby/clutch cover to allow ventilation. that's my 2 cents.

[JAWS]

Ive done that^^ and spaced out the clitch cover and spaced the whole cover. The other choice is large holes on the inner cover or a bunch of well placed small ones. I did three one inch holes in the inner on the last one. Hasnt failed yet.

[govmule84]

I run an open belt and two closed chains on my old Harleys.

The only closed belt I ever had ran in primary with no derby or inspection covers. Now, this particular belt did use a tensioner (what a dumb idea), but I did snap the belt.

IMO, best way to vent it is to throw away the tin primary. Barring that, just pack an extra belt; they're pretty easy to swap on the side of the road.

[farmall]

That and if you break one you won't find a spare locally. Every primary belt drive owner should buy spares in advance. You will need one sooner or later.

[johnjzjz]

tin primarys are already vented - alloy primarys with a belt we use the small feed in the inner and a 3/16 hose to vent it set up

[[JP]]

Originally Posted by JAWS

Ive done that^^ and spaced out the clitch cover and spaced the whole cover. The other choice is large holes on the inner cover or a bunch of well placed small ones. I did three one inch holes in the inner on the last one. Hasnt failed yet.

1" holes??? Wow that's big!
Where? On the underside?
Dont think I can do that now.. I'd have to remove the inner cover.. And that means taking a whole bunch of stuff out the way... Don't have time before trip to Europe... Might have to go the space out the primary cover to let air run through it..

Originally Posted by govmule84

I run an open belt and two closed chains on my old Harleys.

The only closed belt I ever had ran in primary with no derby or inspection covers. Now, this particular belt did use a tensioner (what a dumb idea), but I did snap the belt.

IMO, best way to vent it is to throw away the tin primary. Barring that, just pack an extra belt; they're pretty easy to swap on the side of the road.

How is it easy to change a belt on the side of the road? Everytime I had to fit the belt back on other bikes I had to move gearbox forward and remove clutch basket... And then slide it all on at the same time..

Originally Posted by johnjzjz

tin primarys are already vented - alloy primarys with a belt we use the small feed in the inner and a 3/16 hose to vent it set up

My tin primary seems pretty sealed..
OK except for the back on the gearbox sprocket side, that's quite open there, the cut on the inner primary cover is quite big. Other than that doesn't seem to be any ventilation.

I'll go get some photos now

[[JP]]

only 2 holes there...

2019-05-01_11-16-05 by JP Santos, on Flickr

I just checked and seems like the bolts are 3/16-32, so I'll see if I can find longer ones and make some spacers on the lathe... sounds like the quickest way to sort out this venting thing..

[rhysmort]

JP,

I ran mine with the derby cover off, it was fine for the best part of two years. No belt issues! Ironically I snapped my belt when I had no tins on!

Re changing the belt on the side of the road, you can do it with a screwdriver and a socket/spanner, it's more practice than anything! As long as you don't have it overly tight it's not too bad to do!

[JAWS]

Originally Posted by [JP]

only 2 holes there...

2019-05-01_11-16-05 by JP Santos, on Flickr

I just checked and seems like the bolts are 3/16-32, so I'll see if I can find longer ones and make some spacers on the lathe... sounds like the quickest way to sort out this venting thing..

Just poke some holes in that inner. Grab your hand drill and a decent size bit. It doesn’t really need massive amounts of air.

[[JP]]

Originally Posted by JAWS

Just poke some holes in that inner. Grab your hand drill and a decent size bit. It doesn’t really need massive amounts of air.

And can I run it with more holes on the inner and the outer closed?

I don't want to run with inspection cover off.. That just looks like there's a bit missing....
Would prefer to ride with all of it on but spaced at the bolts, if can't run with it closed and more holes on inner.

[JAWS]

Yes. Run the outter complete.

For holes, think speed holes in a cool pattern.

[JAWS]

No one will see it but you will know its there..

Make it a heart or something.

[KCgran]

Originally Posted by JAWS

No one will see it but you will know its there..

Make it a heart or something.

A heart with a dagger thru it and spell mother in the heart.

[[JP]]

Originally Posted by rhysmort

JP,

I ran mine with the derby cover off, it was fine for the best part of two years. No belt issues! Ironically I snapped my belt when I had no tins on!

Re changing the belt on the side of the road, you can do it with a screwdriver and a socket/spanner, it's more practice than anything! As long as you don't have it overly tight it's not too bad to do!

Ah I see! ok..ok.. that's like a "forcing it in way"... not a proper way of changing a belt. I did think would be almost impossible to properly change a belt on the road side.

I guess a used belt is always better to carry than a brand new one as it will be a bit more stretched.

Originally Posted by JAWS

Yes. Run the outter complete.

For holes, think speed holes in a cool pattern.

Cool, that's good to know.
I have a 1" hole saw about, I'll cut some holes in it and try make them some louvered so it "catches" air and throws it inside the primary.

Having he holes in the back and outer cover completely closed is perfect.

[rhysmort]

Originally Posted by [JP]

Ah I see! ok..ok.. that's like a "forcing it in way"... not a proper way of changing a belt. I did think would be almost impossible to properly change a belt on the road side.

I guess a used belt is always better to carry than a brand new one as it will be a bit more stretched.



Cool, that's good to know.
I have a 1" hole saw about, I'll cut some holes in it and try make them some louvered so it "catches" air and throws it inside the primary.

Having he holes in the back and outer cover completely closed is perfect.

A lot of the TROG crowd do this top and bottom with patterns as Brandt has mentioned, it's a good way to make a workable solution pretty.

Look forward to seeing said holes in two weeks!

[govmule84]

Originally Posted by [JP]

Ah I see! ok..ok.. that's like a "forcing it in way"... not a proper way of changing a belt. I did think would be almost impossible to properly change a belt on the road side.

I guess a used belt is always better to carry than a brand new one as it will be a bit more stretched.

It's not a "forcing it in way." Properly changing a belt on the side of the road is quite simple.

If you lose that front pulley guard, it's cake. Lose the primary, and it's even easier; you'll turn six bolts to swap a belt, and you'll need to readjust your clutch linkage and drive chain, assuming you run a clip-style master link.

But even if you insist upon leaving your setup exactly as it is, it's a 30 minute job roadside unless I'm missing something.

And belts don't stretch appreciably. Take a new belt with you.

[[JP]]

Originally Posted by rhysmort

A lot of the TROG crowd do this top and bottom with patterns as Brandt has mentioned, it's a good way to make a workable solution pretty.

Look forward to seeing said holes in two weeks!

well.. it's not going to be seen as it's on the inner primary and the outer will be bolted on? doesn't need to look pretty.. I'll just make a bunch of holes in it hahaha

Originally Posted by govmule84

It's not a "forcing it in way." Properly changing a belt on the side of the road is quite simple.

If you lose that front pulley guard, it's cake. Lose the primary, and it's even easier; you'll turn six bolts to swap a belt, and you'll need to readjust your clutch linkage and drive chain, assuming you run a clip-style master link.

But even if you insist upon leaving your setup exactly as it is, it's a 30 minute job roadside unless I'm missing something.

And belts don't stretch appreciably. Take a new belt with you.

right, ok. So i was thinking more as minimal tools on the road side, the usual tool kit of spanners.
that now involves taking a big ass socket for that nut, the 1/2 shorter breaker bar, plus the steel plate to lock both pulleys together so it doesnt turn.
yes, taking all those makes it easier as then it can all be slid in together, front pulley and belt.

[rhysmort]

When I do my belt, I get it on the front sprocket, and with a little conviction lever weight on it and turn the pulley with a socket, it will wind itself on. Can do it in 3 mins on your own!