Excessive wet sump problem

I got my 750S on the road and all seemed to be fine for the first couple three outings of approx 10-15 miles each. No excessive runs, drips or errors. Saturday I went for a 20 mi. ride and all was seemingly fine. Later in the day,out again; 20 mi. Stopped a friends house to see oil pouring out of the now chain fractured breather hose. Was there about 20 min., (until the dripping stopped) rode home 3 mi. and the entire LHS of the bike was covered in oil. Lost close to a Qt. of oil. Refilled last night to H mark, started and left run for 10 min. (fan cooled). Checked the level and it was on H. Checked again in 20 min. and it was already below half; checked today and it is almost at L.
I read in another wet sump thread that the general concensus is about 1oz. per day will get past.
Question is: Is my oil pump just plain worn out or am i missing something?
Engine is new, oil pump's not.

Thanks in advance, you guys and gals are the best,

Tom 69S

Where is the 'chain fractured breather hose'? Personally I only fill the tank after running to between the H and L mark, never to H. That's right at 6 pints from dead empty with a filter. I know Nelson is having trouble with his S pumping oil out too, don't know if he has it fixed. So far mine is leaking a bit out the front of the tank hole, but I'm going to put a fitting on that and run it to the ground off to one side or a bottle. It always leaked there. I've heard of S (central tanks and timed breathers) bikes that don't leak, don't know what they are doing. My tank will wet sump overnight to the bottom of the stick, and I can see the filter in the tank after 2-3 days. So far, I just start it and the oil is back in the tank real quick.

I'm not sure the wet sumping is a problem, unless the pump is weak and not getting the oil right back into the tank, then it could possibly come out the timed breather in a gush. Did you tighten the pump up and put the gasket on it?

I have ideas on fixing the oil tank breather tubes if you want to hear it. It may be worth a try, not to hard to do, involves taking the tank off and cutting the top hat off at the top, but I'm not convinced it will work. Won't hurt anything though.

Dave
69S

Dave,
Thanks, you put my mind at ease, at least to some degree. The breather hose is a very soft compound and I guess that once in contact with some hot oil became even more pliable and sagged to the point it contacted the chain, thus creating the BFM. Fixed and reruoted the hose far out of harms way. Upon refire, it did dribble a couple of drips out of the breather hole in the oil tank but that was it. Oil seemed to return to the tank in a prompt fashion. I know the oil pump is tight and gasketed as I had to pull it to degree the cam(engine builder couldn't count to 10 and also thought red locktite was a remedy for strippsd studs and nuts) and installed new studs and nuts. I checked the primary and there's nothing but ATF there so that is good. I do like your bottle idea. That's what I did the other night to see how much it squirted out on the initial fire up. Probably not a quarter inch in a vitamin water bottle standing on the ground.
I quess for now I'll just keep on riding it and see what happens. Got about 80 mi. on it.

Tom

I got my breather and oil hose at the local Ace hardware. It's pretty thick and not real pliable. I also took off the barbs so I could use 3/8" line, they'll come off with a propane torch, they're just soldered on. It'll squeeze over that 5/16" elbow at the timed breather too. That's about what I have on mine, 80 miles, I have the primary off now to fix that leak between the crank and primary cover. I'm going to stick some of the dreaded RTV sealer in there, it's not like it can go anywhere. I also put studs in the crank with red thread lock, makes it easier to put the gasket on and should stop any leakage out of those 3 holes.

Does your breather hose go into the tank at the top hat or beside the top hat, there are 2 style central tanks. Mine goes into the top hat.

Dave
69S

Hi Tom,

Don't fill to the "H" mark on the dip stick. "L" is sufficient and will reduce oil over flow.

Upper Bucks Co, PA...what town?

Dave,
Mine is also top hat. W/O risking disaster, I have grabbed a good handful of 2nd and 3rd albeit wary of the fact that I don't know the bike and the fact that i put alot of together. ( I'm leary enough to wear a REAL helmet) Damn! Practicaly the same HP as my Sporty but 140#'s lighter. Once all is said and done, this is really gonna be fun.

David,
Ottsville; That's on most maps.

Tom

Don't you love that wide torque band? I could drive around in 2nd all day, but it even pulls strong on a steep hill in 4th from 50mph. At my age and all the drugs, it's a replacement for sex.

I've got the primary back on to try and fix the leak between the case and inner primary. Supposed to be a nice weekend, but too many cars on the road then, weekdays are much better here, no traffic. The touristas come out here on weekends for the wineries and views.

Dave
69S

Tom,
I see what you mean. After yesterday's ride that line on mine was drooping down and wedged itself between the inner primary chain guard and the cradle. It wasn't very far from the chain. I pulled it off and routed it over the bracket from the battery tray to the iso mount, right above the left iso, and then back up to the top hat. I suppose one could just shorten it enough in the other route under the iso so it couldn't droop, or tie it right under the iso with a cable tie if you wanted to keep it less visible.

Sidriley was up yesterday and we talked about it. Other thing we could do is plug that stupid dripping hole that goes into the air filter (sometimes I wonder if that line isn't cracked and will leak as long as there's oil in the tank), dump the timed breather out the back somewhere to the side, and vent the oil tank with the top hat spigot to the air too. They could both be taken to a catch bottle also if you wanted to be proper.

I notice I don't seem to have any oil in my timed breather hose, but it's sure coming out the hole into the filter, but not gushing, enough to drip off the bottom of the GB, hate, hate. I think I've got all my other leaks fixed. I may start it up with the breather hose off and see what if anything comes out?

Dave
69S

Here's what cam out of the breather hose in about 2 minutes of running from cold. It didn't start right away, maybe 30 sec. then came out pretty good for about a minute then seemed to slow down. It's enough oil I wouldn't want it dumping on the ground every time I start up. It wasn't frothy, just oil and a few bubbles.



Dave
69S

I might have finally solved my central oil tank dripping problem !
I have blanked off the original outlet on the front of the air filter plate and have instead installed a home made oil / air separator fabricated from an old Amal float chamber which just fits snugly between the frame rails.
I am running the oil line from a Norvil PCV into the bottom of the chamber, the oil then travels up the inlet through the original float needle seat, through a baffle and then drains out the bottom of the bowl back into the oil tank



I have 2 vent lines, 1 from near the top of the bowl and then I have also teed off near the oil tank as I was getting bubbling back in the float bowl.
The bowl is slightly lower than the oil return pipe but the levels seem to work OK. Routing the 'teed' line over the frame rail seems to give enough head that there is no overspill. I have covered a couple of hundred miles going from big puddle to 1 or 2 drips after a long ride.





Maybe not the neatest solution in the world but it saved messing with the oil tank top hat......I was close to selling the bike as the leaking was so frustrating, but the love affair seems to be back on !

That's an interesting solution, I need to study it some more because as usual I'm confused.

But let me tell you what I did. I was hoping against hope that with the rebuild the hole out of the center oil tank would not drip. No way. Started right away and was dripping down through the air filter down on the gearbox and ending up of course on the bottom of the frame and gearbox. Only 200 miles. So I drilled a hole right through the center of a 5/16-24x1" bolt, cut the head off, now I have a sort of close nipple. Tapped a few turns of 5/16-24 into the front of the oil tank breather, put some JB Weld on the 'nipple' and threaded it into the hole. Put a piece of 5/16 ID hose and clamp on the 'nipple' sticking out and punched a hole in the chrome front air cleaner ham can holder, luckily the PO had a hole there that I enlarged for a rubber grommet. Now that hose goes down and drips off the bottom of the frame by the cross-over brace below the gearbox, but I am not satisfied. It blows back on the frame and centre stand. So I am going to make a little catch bottle out of a large plastic pill bottle and put the hose into that between the engine and gearbox and empty it once in a while. It's not like a lot of oil comes out of there, but enough to irritate.

You can barely see the line here and with that line, I have no oil on the engine or gearbox with the original timed breather to the central tank.

I see you have the later tank, my breather goes into that top hat gizmo and I bought a newer tank thinking that would help.

The breathers would be a separate issue. The fact that the oil disappears while the engine is running would indicate a problem with the return side of the oil pump.
Time to pull it off and recondition or replace.

I'm also suffering a similar issue of lost oil (s-type although I've not used the S exhausts), most of which ends up on the ground or my boots, appearing to come from the transfer case. What I now think is happening is wet sumping, that then being forced into the tranny case via the main seal which then leaks out past the drive swash plate and seal. I'd not run the bike for a couple of weeks and went for a short (10k) ride 2 nights ago and there was a fair bit of oil on the drive the next morning. This morning I drained about 1/4 litre of oil from the sump, checked the oil tank level was still ok and rode to work (about 40ks). Couple of spots of oil under the bike. I'll check the contents of the tranny case when I get home.

Dave,
If you are suffering from oil leaking into the primary case from the sump (through either the main gasket or the 3 bolts that hold the primary inner on) that can be cured, either by installing a modern type crank breather, or what I did, I got rid of the 3 bolts from the inner primary into the engine case, installed 3 studs with red locktite in the engine and used nuts to fasten the inner primary on the studs. The lower stud and nut will have to be ground down a bit to clear the chain. I'm still using my original timed breather and the only leak I have is out of the oil tank breather tube, but then this is a very recent rebuild and I used Hylomar Blue Racing formula gasket sealer and for the flanges too.

Dave
69S

Reroute the breather line to the back of the bike like on a triumph. I did that on my MK III amd my 73' 750. I 'll get excess condensation in the line at times and a blast of muck will come out occassionally. On anyone standing behind the bike :roll:

Tim_S

Well I finally got 10 mins to check the tranny case and it was over the limit hole, but couldn't have been by much, 10 to 20 ccs came out I'd guess, but then after riding to work and back Thursday, a fair bit of oil would have been liberated out the final drive in the process. There was also a decent oil spot on the paper I left under the bike in the shed, another couple of ccs I'd say.
Dave, I used Copper crush washers under those screws and fitted a new main seal only a couple of months back, so I thought it should be pretty oil tight in that respect - wet sumping aside.
I'll clean up and repeat the experiment with a purged sump.

Cleaned everything up this morning, but before cutting loose with the pressure washer checked to see that the oil was coming from the tranny case at the final drive output. Think I'll install a valve in the oil supply line and see if the tranny case fills again while it's sitting. Just need to find a suitable valve!