Little background on the bike, inherited it from my grandfather who passed away. he owned his own bike shop, vietnam vet, he did a lot of strange work!

it’s a alt/gen STD cam case (trying to figure out the year) with a 88” big bore shovelhead top. started it after sitting 10 years when i first got it, using the kick. ran strong. but i couldn’t keep it stock. im sure he’s rolling in his grave..



first day i got it shipped to my house. RIP GPA




side profile of what i’ve done




left side profile



terrible top down photo. i thought i had better photos!




got the bike tore down, put a magneto in it, etc. eventually went to kick it over. oil was wet sumping out of crankcase breather on every kick. ALL the oil in the tank was in the crank/bottom. started my research.

check ball most likely stuck / not working! ok! ordered that.


i took the chest cover off, inspected and seen that oil was coming out of the pinion oil hole, free flowing while line connected.







this bike had its original oil pump replaced with a new one from a shop i took it too. i called them today to see what they thought, etc. after doing step #1 below didn’t work. they were scratching their heads themselves.


here are the steps below i’ve done and what im am doing going forward


1. installed new check ball and spring today. did not solve the issue. everywhere i read this usually fixes it. however this is a brand new pump. (brand is pro1? can’t remember what the shop said it was)

2. blew out the passages i could, seeing if i could free up anything stuck, etc

3. started looking into other pumps. im wondering if this pump is flowing into a hole that it shouldn’t be BEFORE the oil gets to the check ball line.

4. ordered tools to pull off oil pump and inspect what oil passages are there behind the pump; to order correct s&s pump. no idea what “year” this bottom end is.



here are more pictures if they help. i just want to know what else i should check or do in the meanwhile waiting for my new snap ring pliers to get in (mine were too big)



with oil line clamped; oil no longer comes out of hole



the pump in question! no visible markings to get the brand.

 

If its flowing past the check ball then its the seat in the pump thats letting it leak past the ball. There is a tool you can get or you can make one to dress the seat in the pump body.

 

Welcome to the forum

 

The flat side alt engine is an old mod have not seen one in a while originally we used a panhead case right side married to an electric start case right side ( old guy thing and kicking it over ) - creative machining has to happen - then the left side hole for the genny a evo sporty oil filter housing and 3 1/2 filter worked great

Sumping flat side engine

we had fifty luck with the reed breather as the engine piston ring seal is not as good as the evo - iron jug way hotter - what happens is the static compression distance - performance cams duration - over whelms the cavity with oil and it drains off when parked —- one of the things we found when chasing this

2 - as said the oil pump ball and seat in that Midwest oil pump uses the S&S directions for feed drilling a flat side - i see he went a different way BUT you might have solids as lifters - Allen drill out tap thread and socket head screw - the older way to mod nothing incorrect BUT the line pressure is too hi as that pump is hi pressure and hi volume - iron pump is dribble and a little more dribble to return it to the tank

the first alloy oil pump was 1968 and the pressure spring was in the idea of a fast dribble have them in stock will if i remember to post a part number and picture —
we replace the spring in the pump with the original one so the system does not become overwhelmed like you now have BUT in my shop we would remove the oil pump and re seat the ball seat dykem blue the hole ( it comes off using lacquer thinner ) and create a valve seat kind of margin small but visual - all you will see in the hole is maybe a line as its just cut straight - then we use valve super fine grinding compound and lap the old ball to the seat till its a different color then the pump insides - now it will hold the oil back re use the spring on that one but a new 3/8 ball - with this mod you should be good to go

we also use automatic transmission assembly grease on the gaskets to hold them in place and it softens the paper just a bit so the seal is way better then with out it and dont make it real thin - thick is fine its also used in the gear set so the oil pump gets an instant suction at start up —- good luck

 

Spring is actually a iron pump that was again up dated when the engines went end oiling in 73

we also use the S&S breather as it has an elongated oil sip slot instead of a drill hole to increase the suction for the lower unit



13-0107 is the v twin number for the spring

 

Cleaning up the rough cast hole in the case ( breather window ) while in there is a good idea too

 

thanks for the reply’s everyone. to answer some questions

i have solid lifters.

the bike had a nose cone alt/gen on it originally with a dyna ignition. i removed all that, went flat, etc cuz i got a morris magneto.



the reed breather i just installed. Threw that in there before i seen this oil leaking out of the oil hole in the pictures even in static.

i’ve heard they don’t work, i’ve heard they do work, so let me know what you think. i have the original breather gear, no idea on the make. i do know it appears to open 10 TDC and 10 after BDC. i just bought the reed as it looks a lot easier!



i will say, there’s a decent gouge in the breather port.

the company replaced my pump cuz they said they did see gouges in it. so something went through the pump at some point before me getting it.



based off what i’m reading, once i pull this pump apart from the case i should see what holes i have where for oil passages. from there im more than willing to listen to what you guys suggest or see.

 

If its not starting then the engine gearing has been changed to clockwise and not counterclockwise

dyna is clockwise original flat side is counterclockwise

 

although i’m having starting issues, im going to make a separate post about it. that being said, the magneto impulse coupler fires as i approach FTDC compression, so i know the rotation is corrrect.

 

I ended up just buying a S&S Oil Pump. Seems to of solved this issue. Thanks everyone for chimming in. I assume the Root Cause was the need to LAP the check ball seat; but it was a brand new pump. No idea still on the make of it; it has zero markings on it!