Back on the road... Again...

Okay, took her around a bit more today, probably a good hour on the road. Up to 70 this time, still smooth and strong. Apparently you can only get down to the end of the block once you've turned the fuel tap off... Ugh...

Couple questions:

1. My mediocre riding skills resulted in another stall at a light, this one in 3rd gear (wonder why it stalled...? ). Anyway, off to the side of the road, I tried to pull in the clutch and downshift to neutral to kick start, but it didn't seem to work. I had to leave the clutch out and roll it a bit to engage a gear (it seemed to be caught between gears or something) and then I was able to downshift. Am I doing something wrong? Normally, I would obviously downshift with the engine running and not have this issue, but is this normal gearbox behavior? Sorry, I hope this makes sense.

2. I'm still looking at some drops of oil under the primary case after a ride. This only happens immediately after a ride although I'm sure it's leaking on the road - but there isn't a large pool the next day or anything. I initially thought it was the big o-ring sealing the primary, but on closer look I think the oil is running down the back of the inner primary case. I don't think it's the wet sump issue and additional oil coming into the primary (but I could be wrong), because looking into the primary, the oil level doesn't look high. The clutch doesn't grab or slip either, seems to be functioning normally. The grommet on the alternator wire is hard and a bit loose and I'm sure that's leaking a bit, but the quantity and spread of oil coming down the back of the inner primary seems to be too much to be just from that one grommet... Any thoughts here? I'm going to take the cover off again anyway to deal with this grommet, and then I'll verify that the oil level is indeed correct. I used the level hole when filling it, and looking through the inspection hole it doesn't "look" high... But maybe I'm wrong. I don't know, was surprised it was still leaking I guess.

1. My mediocre riding skills resulted in another stall at a light, this one in 3rd gear (wonder why it stalled...? ). Anyway, off to the side of the road, I tried to pull in the clutch and downshift to neutral to kick start, but it didn't seem to work. I had to leave the clutch out and roll it a bit to engage a gear (it seemed to be caught between gears or something) and then I was able to downshift. Am I doing something wrong? Normally, I would obviously downshift with the engine running and not have this issue, but is this normal gearbox behavior? Sorry, I hope this makes sense.

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Thats normal, the gearbox is a constant mesh type, the gears are alternatively locked to the shafts to get the correct gearing using dogs on the side, with the engine not running you have to move the bike forward and backwards until the dogs allign to get a gearchange.

Your primary chaincase leak could be one of several, where the gearbox mainshaft enters the back of the inner chaincase, the 3 bolts that fix the inner chaincase rear to the crankcase, the alternator grommet plus others. All will be made worse if the crankshaft seal has gone as your chaincase will be pressurised.

Spaulding said:

I tried to pull in the clutch and downshift to neutral to kick start, but it didn't seem to work. I had to leave the clutch out and roll it a bit to engage a gear (it seemed to be caught between gears or something) and then I was able to downshift. Am I doing something wrong? Normally, I would obviously downshift with the engine running and not have this issue, but is this normal gearbox behavior?

Click to expand...

That's normal for just about every motorcycle gearbox, as each driving "dog" on a particular gear needs to line up with the corresponding recess in the gear next to it before that gear can be selected, and once the engine has stopped, it is something of a lottery as to which gears will select immediately and which ones won't unless the bike is rolled either forwards or backwards slightly first.

http://www.oldbritts.com/gearbox_info.html

Spaulding said:

The grommet on the alternator wire is hard and a bit loose and I'm sure that's leaking a bit, but the quantity and spread of oil coming down the back of the inner primary seems to be too much to be just from that one grommet...

Click to expand...

The seal behind the clutch may need replacing?

Another false leak is the chain oiler.
After lubing my chain hot with PJ Black in an aerosol can I can go on a 30-40 mile ride and find the excess
lube had flipped off the chain. It lands on the small shield(attached to rear of primary cover) just in front of the drive sprocket.(small sprocket usually 19-22 tooth the chain attaches to and you can't see)
It then runs down the rear of the inside primary cover and under the primary till it drips down on my new down pipes.
Then when I start it I get a white smoke burning off the oil and baking a nice lube residual on the bottom of my again new pipes.
Initially, I too thought the primary was leaking.
Now, I just wipe the underside of the primary and pipe before starting.
If its oil it will look like an oil drip.
In the case of chain lube it is a black looking liquid drip.
Check your chain oiler if installed still and watch when lubing the chain.
Marshal

Thanks very much guys. I'm glad to hear that the gearbox behavior is normal as that was my main concern after this ride.

I'll need to do some work to figure out the primary leak. It is certainly regular engine oil, as it looks like the clean, new oil I put in the tank and the primary - also, I stopped off the chain oiler. It seems that the oil is running down from the middle/rear of the inner primary. So it might be the clutch seal (although I thought that was felt and the level shouldn't be up that high anyway?), or the primary might be under pressure. Is there an easy way to figure this out, or am I stuck with disassembling the whole case? I do have the workshop manual and the special tool for the clutch stack.

Again, thanks, this forum is really a great help.

Fixed the leaky primary - swapped out the alternator line grommet, sanded the primary cover, fitted a new sealing band from AN with grease (this one seemed to be more "solid" rubber than the one I put in before which was spongy). No bonding compound this time. A long ride and no leaks whatsoever. Such a cool bike. So far the stock paper gaskets with grease for the covers and now a greased band on the primary has been my ticket to ditching the leaks.

One issue - the oil in the primary seemed to have more metal sparkling in it this time. I was thinking this could be due to the fact that I tightened up the primary chain and that it might be wearing a bit too much now. But I tightened it according the the guidelines in the rider's book - 3/8 in up/down movement (maybe even a tad more). However, it was quite a jump from where it was when I got the bike and the chain seemed very loose.

Anyway, I'm wondering if the up/down movement recommended in the manual is way off or if the metallic particles in the oil might be related to something else (clutch)? I backed the primary chain off just a bit, now maybe more like 5/8 or close to an inch up/down at the center points and I don't notice any difference in the way it sounds. It's still tighter than it was when I first checked the chain. Am I missing the basic concept of how to determine up/down movement? I figure anything is possible when you are relatively clueless about such things...

Sounds like your chain tension is just fine.


However, you may need to buy a new primary chain. They were out and shed off lots of tiny pieces of metal from the constant flexing goin on.

I had the same metallic primary issue years ago, a new chain took care of the problem.


Nowadays I am chain and leak free with a belt primary. How old, miles, is your chain?

Thanks very much - bike has about 9000 miles so I would assume it should be good for a bit longer - the sprockets and the chain "look" fine, but I will keep tabs on it and check/change out the primary oil again in a few more Ks...

I put 40k miles on my 71 Commando before I sold it in '78 and other than an occasional check/adjust, the chain was fine. IMHO it's just about the last part on a Commando that will need replacing as long as you keep lube in the chaincase. Actually, I doubt it would ever need replacing with proper tension/lube.

The only way to know if primary chain tension is correct cold
is to check it when hot. That's what matters, alot.

If you can lift the links out the sprocket valleys even a little,
no matter the chain tension, its worn too much and now
wearing on sprockets.
Rich Stone form Iowa, a long distance 850 addict had his triplex
chain disintegrate before he got to North Carlina rally.
I've seen mine shed some of the link shells before renewed.

Commandos are uncanny frustrating motorcycles, with
uncanny delights when right.

hobot