When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
OK im going to try and put as much info as I can in this and hopefully the gurus here will have some good input. I have a 84in stroked shovel . They are 1972 cases. At some point the person who built it upgraded to the end oiler pinion shaft and also the cover to go with that . Since I have owned this motor I have had an issue with the front cylinder puffing smoke at an idle when warmed up . I recently put new barells ( yes they were modified to move the oil port to case drain ) new s&s pistons and rings and even a new set of s&s heads . Its still does the same thing it did with the old heads and old pistons and barells. This made me think hmm maybe it's an oil issue. The gauge jumps around some but cold idle its pegged past 60 . Warmed up idle its at 40psi and just a little extra rpm sends it right back to 60 plus . I noticed the oil pump that was used is a # 31-6048 and in the literature I have read thats for a 69 and back motor .... someone did make the mod where they plugged the oil overflow next to the breather and they did drill that extra hole above the pinion feed hole that I guess is for chain lube? But one thing I noticed is that there was no hole drilled above the breather for a pressure relief.... could this be my issue ? Before I start drilling things I need to figure out where to go with this . It appears the correct part number for a cone is 31-6050 ...
Last edited by Jd72chop; Dec 30, 2025 at 06:27 AM.
Will need to go into my notes. But the explain you gave as i was reading i thought its a valve seal - worn valve guide and or both - you did not say you do any head work - the holes are a good thing but did you blind with jug with a brass pipe - so no oil is going into the oil rings when the piston uncovers the holes at BDC
Will need to go into my notes. But the explain you gave as i was reading i thought its a valve seal - worn valve guide and or both - you did not say you do any head work - the holes are a good thing but did you blind with jug with a brass pipe - so no oil is going into the oil rings when the piston uncovers the holes at BDC
Pretty sure i solved the mystery . to answer your question ,yes the cylinder drains were plugged with tubing . The heads are brand new s&s and it did the same with harley heads . The builder used the wrong pump . I have the correct pump on the way . The bike was getting full pressure to the top end and no pressure to the pinion . It wasn't together that long and bottom end seems fine. Plus it was being bathed in 60 psi of oil from the head drains . Ill report back when the new pump is on
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.
S&S oil pump case mods and confusion?
