Now where is this oil leak coming from?

Thanks Jim, what do you use? The only reason that i used mobile 1 was becuase it was recommended in an article i read entitled:

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Toroco MPZ. It has a high zinc content.

DogT said:

Another thing that might help. I removed the bolts from the inner primary to the crank and replaced them with studs and nuts, unc in crank and unf in primary, you can get 1" ones at your local auto store for a few cents. Red locktite the studs in the crank after thoroughly cleaning the crank threads. That should stop any migration from the engine to the primary. It also makes it easier to put the gasket (if you use one) and primary inner on. The bottom stud and nut will have to be ground down a bit to keep from contacting the primary chain.

I use Valvoline VR1 racing SAE50 in my bike, it's like honey and has the higher zinc content in it. Keeps the oil pressure up even at idle.

Just my preference.

Dave
69S

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Wow, that is one thick oil. Do you use that in your primary chain case too?

Johnnymac said:

Wow, that is one thick oil. Do you use that in your primary chain case too?

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Yes, actually it's what's recommended in the early Riders Handbook besides the 20W50. Same for the primary.

I've had people tell me it makes it hard to turn over, but I haven't noticed.

Dave
69S

DogT said:

Johnnymac said:

Wow, that is one thick oil. Do you use that in your primary chain case too?

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Yes, actually it's what's recommended in the early Riders Handbook besides the 20W50. Same for the primary.

I've had people tell me it makes it hard to turn over, but I haven't noticed.

Dave
69S

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Sorry for all the questions... But what is the recommended oil level? Thank you so much!

Part number 38.
Put it on the side stand and add oil till it starts to trickle out this plug. Approx 5 to 7 oz's
http://www.oldbritts.com/1972_g8.html

Johnnymac said:

Sorry for sll the questions... But what is the recommended oil level? Thank you so much!

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Between L and H. Not to be a smart ass, but I tend to keep my oil level on the L mark. My bike wet sumps in about 2 days and I just don't worry about it. I just start it, make sure the oil is returning to the tank and all is fine. Never had a problem, but I think the wet sumping produces a slight leak at the bottom most crank case stud. I forget what model your bike is, but mine has the central oil tank and has a different breather system and the oil feed and return are both at the bottom right side of the tank behind the air filter.

After rebuilding the engine, I put 3 US quarts in it, but when I change the oil (hot), I only seem to get less than 2 Q out of it and only replace that amount. Even with the oil filter.



Dave
69S

Early dip stix were a bit too short so if much oil showing then its way more likely to over flow where ever. When I let if just seek own level by blasting on down hyw it ends up just showing on end of my '72's sticks. I have thought to add a short chain with magnet on end to both measure level and suck up the iron dust to monitor and less sediment maybe. Something as mysterious and juicy as a Commando implies to me a female gender character, mean as that can be.

Thanks guys. I have a 72 Combat. I had never really heard about wet sumping since i just got my Combat about a month ago. It was restored in 2005 and i am still learning about this bike's eccentricities.

hobot said:

Early dip stix were a bit too short so if much oil showing then its way more likely to over flow where ever.

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I'm not sure which early dip stix you're talking about Steve, but the central oil tank has a totally different dip stix than the later (71 and up) side mount tanks. I actually think the markings on my central tank stix are just fine, I just tend to leave it on the low side for the wet sumping issue and the timed breather, and If I get comnoz's sump breather, that issue should disappear.

Dave
69S

pvisseriii said:

Part number 38.
Put it on the side stand and add oil till it starts to trickle out this plug. Approx 5 to 7 oz's
http://www.oldbritts.com/1972_g8.html

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I am of course referring to the primary here. FYI

Ugh, regular Commando's - Combat included drool oil through pump into sump but Combat have another version too, at high rpm which Combats are prone too they sling, pile oil up rear of cases away from the front oil drain so tend to make a mess.
It slightly helps to leave engine crank near TDC. If I can see oil in tank then its enough to start to get the breather hose as well as the pump both returning oil to tank in a hurry.

Then there's over filling primary oil level and chain over tension dangers and the fork oil level to increase somewhat. Top off tranny too and ride a 1000 miles or so for it to seek its innate level too. Then worth a wash down that lasts a bit longer.

Well, i drained the entire system of all lubricants. Replaced the gearbox oil with 90 weight. Thoroughly cleaned up the primary and filled with 6.5 ounces of 20w 50 castrol. Then filled the oil tank with Morris Golden Film SAE 40 to the "LOW" notch on the dipstick. I took her for a spin and so far no leaks. I got my mikesxs pcv valve in the mail but havent installed it yet.... I will more than likely install it, but need to get a few inches of oil line and some clamps. I have a feeling that my problems were due to too overfilling of oil.... I will keep you posted. Thanks guys!

Not wanting to make a permanent install of my pcv valve, i rigged this up just to see if it stops my leaks first. Essentially, I used JB Weld to adhere the valve to a piece of aluminum. After it cured, i used the 3M super heavy duty double sided tape to stick the valve to the back of my airbox plate. I havent driven it yet, but it is all ready to go.

FWIW, no real need to mount. Probably 99% of the people who put this inline as you are just have it suspened on it's own.

Also, as you run, moniter the level of oil in the primary. If you wait to the point to where is leak out the back of the primary, the level will be way too high. My feeling is that once your valve is in place, your primary will maintain an acceptable level.

My 850 finds its own oil levels as well. Even in the gearbox!!!
After thoroughly going through the oil system after first getting the bike, I replaced the 2 x rubbermounts on the oil tank, filled the oil tank(including the new filter) to an acceptable level between L and H on the dipstick( I use HPR 40 Penrite 25W70 in engine and chaincase) only to find I cracked the rear mounting bracket on the oil tank after a 120km run. Repaired and refilled tank with a little more oil than usual, only to find I thought i had a crack in the oil tank asthere was oil coming out verywhere over the same 120 km test run. Let the oil settle at its on level , marginally above the L mark, no more over pressuring of tank or leaks there fore no crack in the tank as I checked!!!
Gearbox I run Redline Shockproof oil,(blue in colour) and fill to the oil level bolt hole.when I do the same 120 km run I get a leak at the sprocket until the level finds its way down marginally below the oil filler bolt hole, no more leaks and a maintained oil level!! I check regularly by removing the clutch cable inspection cover on the gboxand check the level just below the level bolt hole, using a torch.
All runs sweet and no leaks anywhere!!!

I'm not sure which early dip stix you're talking about Steve, but the central oil tank has a totally different dip stix than the later (71 and up) side mount tanks. I actually think the markings on my central tank stix are just fine,

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These are my two, the short one was on the bike when I bought it and the longer is it's correct replacement. You can just see the High and Low marks on each and their different positions.

Keith1069 said:

I'm not sure which early dip stix you're talking about Steve, but the central oil tank has a totally different dip stix than the later (71 and up) side mount tanks. I actually think the markings on my central tank stix are just fine,

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These are my two, the short one was on the bike when I bought it and the longer is it's correct replacement. You can just see the High and Low marks on each and their different positions.

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Isn't the one on the right the factory dipstick? That is what is on mine and judging from the look of it, I am pretty sure it's OEM. Obviously the one on the left is an aftermarket. Those are certainly different oil levels though.

The early Commandos had a sight tube. The S and 70 Roadster with the central tank, filler cap 06.1338, and the 71 cap is 06.1649. Mine, 06.1338, looks suspiciously like the one on the right. The H mark is 2 7/8" from the edge of the cap and the L is 3 7/8". I thought the 71 and newer were longer, kind of like the one on the left, but I've never seen one.

Dave
69S

My 72 74 and 75 are like the one on the right

Phil