I think 50 wt engine oil is too thick for the primary. The primary fluid is basically only there to cool the wet clutch and prevent the primary chain from rusting. I have found that ATF is much better in the primary than 50 wt engine oil. The thick oil tends to make the clutch not want to release all the way - at least on Bertha. I think ATF is even thinner than 30w engine oil - although I really don't know for sure.

I used to run AMSoil MCV 20W-50 in the engine, tranny, and primary - but I had a hard time finding neutral with the MCV in the primary. I switched out to Mobil 1 Syn ATF in the primary, and it's much easier to find neutral now.

I also switched to Mobil 1 LS 75W-140 Syn Gear Lube in the tranny, and it really smoothed out the shifting clunk.

 

Thanks for the reply. It's ATF so definately comin from the primary. Could be a seal at the jackshaft or mainshaft, but I reached up under there after a ride and it was dry. I'm starting to get this sickening feeling that I have a cracked primary. I'll check it out this winter. Might be a good time to switch to a later model clutch, oh and 6 speed tranny, oh and a 124 Ultima! Well I can dream can't I?

 

Yikes! That doesn't sound good...

Dream all you like! I dream about the new S&S V111 Touring engine they just came out with. Built for lots of low-end torque on heavy bikes... it would be perfect for Bertha, and for some reason it's far lower in price than their other engines... $5395 list in wrinkle black with IST ignition and a 3-year warranty. Sounds almost too good to be true for an S&S engine...

 

My '96 Electra Glide had a primary drain plug leak also and like you I found the new plug wasn't any better. I removed the primary cover and redrilled and tapped the drain hole to 7/16 fine thread. Picked up a stainless socket head cap screw from McMaster Carr, used some teflon tape on the threads and put an o-ring under the head, no more leak. The 7/16 head just fits in the recess area on the primary cover, and the thread size isn't a whole lot larger than the pipe thread already there. Just make sure you cut the new bolt off so it doesn't make contact with the clutch basket/ring gear inside.

 

Maybe the pressure from Ultima, and the economy, is getting to them.

 

Sounds like a plan, maybe I'll pull the primary cover off one more time and give that a try. Thanks.

 

Deja Vu all over again. I had the same thing happen recently with my '97 fatboy. Thought it was shock oil, since it appeared to be dripping from the left shock (softail). Ruled that out and then assumed it was engine oil overflow (had just changed oil). Nope. Next, assumed it was gas--but the finger swipe test showed it was oil. Bingo, $400 and a new primary inner seal later and all is well. You don't fix that on the side of the road ;-) Overalll a fabulous bike, but hey, s**t breaks, ya' know?

 

Yes, it does! Bertha has so many leaks on those primary seals, I don't know which of them are leaking... probably all of them.... 15 years is a long time for a seal.

Kind of like that penguin car joke... "Looks like you blew a seal. Nah... that's just a little ice cream!"

 

Thanks guys for all the ideas, I think it would be a good idea to change the innner primary seals. First I am gonna clean the engine spotless and keep a close eye on any leaks. It looks like the derby cover was leaking a tad.

 

With all the other stuff you tried it might not help but are you aware of yellow teflon tape? It is made for use with oil unlike the white stuff.