closed primary...can I???

[Kowalski0A5599]

Hello, Was wondering...I have the stock primary set-up on my 65 pan. Oil from primary back into the engine. I do not like this, but also do not like letting it drip out all over the place either. Years ago I read that you can "close" the primary and just add enough oil to keep the chain wet. ...as long as there are no leaks. Just need to keep it vented. Will this work? Do you need special clutches set up to be "wet" all the time? Sure would keep the oil off the rear of the bike and NO junky clutch contaminated oil back into the engine. Any thoughts?
Thanks.
Regards,
Ben

[drinner-okc]

Ben, isolating the Primary is apopular if not common upgrade. I did my 65 in 1976. The Primary does have to be in pretty decent shape. There are several places you need to pay attention to. There is a plate that goes between the Starter & the Primary with an o-ring that came out later, you'll need to add that. And under that Starter area can get ground into by loose chains, especially by running a larger Transmission sprocket. You need a 'sealed' bearing on the mainshaft & it needs to be tight in the inner Primary. Then either make a gasket or light silicone between the motor case & inner.
There is a 1/8" line that supplied the oil onto the Primary chain, I knock it loose, turn the hose fitting down & reinstall it, then put enough hose to hang below the grame rail to vent the whole housing. The vent line and return line can be plugged with pipe plugs. Then they are eliminated on the oil lines.
Yes, you'll need clutch discs designed for either wet or dry use, they are common now. Then a good primary gasket & surfaces is needed. I use about 22-24 ounces of non synthetic Primary lube, I used Dexron ATF for years with no issues.
The Primary chain will run much cooler & last longer & require fewer adjustments.
My only caution: If the bikes sits for a period. After starting the bike, operate the clutch quite a few times to allow the plates to get oiled evenly. If you don't, when you put the bike in gear it may grab & go.
drinner

[1951 adam]

Did you consider running a closed belt drive, I'm not a big fan of them, but it should lighten up the drive train, and you can run your dry clutch....and no oil leaks. I'm currently running an 1 1/2 belt,after 12 + years, never an issue

[Kowalski0A5599]

drinner-okc
On my bike I have no electric start...strictly kick start. I have block off plates in place now that are where the starter would go. So, I'm set up there. Last time I was in the primary, it looked pretty good...nothing torn up or gnarled up or anything. I guess I will need the sealed bearing on the main shaft then? Where to look for them from vendors? Part #'s or actual name of part? I not quite sure what you mean by clutch discs for wet or dry. Will the ones I got in there now work? They are the stock clutch discs. I guess they are more designed for dry, but oil is splashing around in there from the chain oiler. Will they be ok? Oh yeah...I noticed the okc after drinner. Oklahoma City? I'm down in Sasakwa, kind of near Seminole. Which will mean nothing if okc ain't Oklahoma City. Thank you!!

1951 adam,
Several years ago I got real close to going to a belt drive set up...then life kinda dog-crapped on me. I have decided I like the stock lookin' set up this time around. Thanks for the tip though.

Regards,
Ben

[JR JOHNSON]

ben,go to shovelhead.us,than to there tech stuff.good section on this.hope this helps......with respect ,,,JR.........RUBONE,remember the days, vacuum testing primary s............JR

[Bosheff]

Ah yes. Vacuum primaries. At best the vacuum system may have worked until the first time the electric start was used or until the drive chain knarled up the tin that the o ring mounted in that surrounded the starter shaft. A real piece of engineering ingenuity the factory came up with. Almost as efficient as hydraulic lifters that were supposed to function without oil....bosheff

[Cotten]

In spite of the faults of the Factory design, I advise against sealing the primary.

Only the most anal of mechanics upon their own machines have any luck with it.

....Cotten

[Kowalski0A5599]

Hello,
Seems like a 'logical' kinda upgrade. Cotten, when you say any luck with it, do you mean it doesn't really work out as good as the idea sounds? Like not reliable or a lot of up-keep to keeping it working properly? Seems like some other guys have had good luck with it. Could you give me a couple of examples of why it isn't such a good idea? I am interested in all points of view as I need as much info as my feeble mind can absorb.
Thank you,
Regards,
Ben

[Kowalski0A5599]

Anybody want to chime in on this? Just kinda wondering what may not be so good about it.

Ben

[JR JOHNSON]

ben,did it to my 72,best thing in the world,you think about,the trash from you clutch,chain,chain adjuster,were is it going to go,to your breather valve,on the outside of the screen,spend around,tear up your breather bore,spit it in your cam case,than to your pump.if your going to ride it,but not knowing anything with the 65 inner primary,i would take it off,reseal it,with a sealed bearing,if it's possible,plug up except the oil in,put a little hose on it,for the vent,if you have a ring gear on the hub,just about a half quart of 10-30 motor oil,your in business. if it's possible,do it.go to that web site i told you earlier,they'll help you there too.........with respect.JR

[Kowalski0A5599]

JR...I did go to that site and it seems like an easy way to upgrade. I sure agree about all the crap and junk going back to the engine. I would not hook it up that way as it just seems like a bad idea. I would let it drip and check the oil all the time. That's what I did for years. Just don't want to do that this time around. Anyway, I got the site on my favorites list now. Found clutch kit that will convert to it...wet clutches. I'm sure leaning strongly towards doing it, was just curious of why Cotten is against it. I appreciate the input and the tip to the site.
Thank you!

Ben