unusual oil leak... HELP!

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In a previous topic I asked about what the best breather set up is best, and the xs650 breather is what I chose.
The pictures show the breather in place and where I am gushing (yes Gushing) oil after a medium ride and riding in the nieghbor hood of 5000rpm. After removal of the breather and starting the motor oil flows out the breather tube as well. I just don't understand why oil would come out from where it is so much, I have a copper washer and a good sealant at this area and I lost most of my oil in a short ride. Here are the pics...
Breather tee
unusual oil leak... HELP!

Oil Gusher
unusual oil leak... HELP!

XS650 Breather
unusual oil leak... HELP!

XS650 Breather
unusual oil leak... HELP!
 
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I'm pretty sure the breather is in the right orientation. If not, it would surely cause a leak.

I'd get a couple spare pieces of hose and try the breather in a couple locations (to test) and see if you get better results. That will let you know if it's a location or orientation issue.

We assume that you aren't wet sumping? Drain sump and restart and see if you have the same problem. As always check the oil level carefully.
 

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I noticed that you appear to have the breather pipe attached to the original breather as well as the modified outlet at the rear of the timing case?

I'm not sure that's a good idea, as a fair amount of oil gets blown up that original breather if there's any amount of oil in the sump, and I'm not sure how the XS650 valve would cope with that?
Generally the original breather would be blanked off when the timing case breather mod. was done.
 
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L.A.B. said:
I noticed that you appear to have the breather pipe attached to the original breather as well as the breather outlet at the rear of the timing case?

I'm not sure that's a good idea, as a fair amount of oil gets blown up that breather if there's any amount of oil in the sump, and I'm not sure how the XS650 valve would cope with that?
Generally the original breather would be blanked off when the timing case breather mod. is done.


The blanking plate was not available from OLD BRITS at the time I ordered things so I capped off the tube of the original breather and still had oil leaking from this area of the case. I take advise from other Norton owners I trust and was told teeing this would be OK.
 
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To add to the symptoms the timing case was sevierly hot while the oil filter seem unusually cool, is this wet sumping and how does one drain the sump?
 
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Nortasaki said:
To add to the symptoms the timing case was sevierly hot while the oil filter seem unusually cool, is this wet sumping and how does one drain the sump?

Big arse plug on the bottom of the engine.

Can we assume you did nothing else while installing the breather apparatus?
 
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In one of the numerous threads on breathers, Jim Comstock mentionned that the timing case if not modified would have a LOT of oil in it and it would be whipped to a froth by the gears and the timing chain. The breather valve would try to pull the whipped oil out and shoot it out.

Where is the "T" going?

Jean
 
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Jeandr said:
In one of the numerous threads on breathers, Jim Comstock mentionned that the timing case if not modified would have a LOT of oil in it and it would be whipped to a froth by the gears and the timing chain. The breather valve would try to pull the whipped oil out and shoot it out.

Where is the "T" going?

Jean

I was lead to believe that it would be OK to tee with the old breather, maybe it should be teed in between the new breather and the tank? :?
 
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Jeandr said:
In one of the numerous threads on breathers, Jim Comstock mentionned that the timing case if not modified would have a LOT of oil in it and it would be whipped to a froth by the gears and the timing chain. The breather valve would try to pull the whipped oil out and shoot it out.

Jean, would this be the case with all Commandos, or just the 750s? I see from the pics that Nortasaki's Commando is a 750. I ask this because I have just fitted an XS650 breather valve in the same location as Nortasaki's on my 850 Mark 1. I haven't noticed any problems so far, but I am concerned. Wasn't the original breather location on 750s at the drive side end of the camshaft?
 
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Nortasaki said:
Jeandr said:
In one of the numerous threads on breathers, Jim Comstock mentionned that the timing case if not modified would have a LOT of oil in it and it would be whipped to a froth by the gears and the timing chain. The breather valve would try to pull the whipped oil out and shoot it out.

Where is the "T" going?

Jean

I was lead to believe that it would be OK to tee with the old breather, maybe it should be teed in between the new breather and the tank? :?

If this is a Combat motor, just use the breather from the bottom of the crankcase and plug up the one from the timing case, at least as a trial, you should see an immediate difference I would think.

Jean
 
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Jean, various contributions that I have read on different sites indicate that the standard Combat breather position is liable to vent oil out of the breather because the scavenge pickup is too far forward and the scraper flange on the case tends to keep the oil at the back of the cases, based on this I would try to block off the original breather hose and see how much oil comes out the timing side breather. I do have a vested interest in this as I have done the scraper removal and repositioning the scavenge pickup mods on a set of cases I have waiting to go in a bike. I have yet to drill the vent holes from the timing chest through to the crank case or fit the breather at the top of the timing chest and was thinking of trying it out first with the standard vent in place, however after reading through this thread I am now leaning towards doing the full modification as outlined on the 'Old Brits' technical page.
 

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Nortasaki said:
I take advise from other Norton owners I trust and was told teeing this would be OK.


I'm not questioning the advice you were given elsewhere, but I'm curious to know if that advice was given with the knowledge that an XS650 PCV would be included?

I must admit I have no personal experience of the XS PCV, so I have no idea how well, or badly, it copes when it has to deal with a certain amount of oil being pushed through it, which the '72-73 case breather probably will do? Personally I would be inclined to disconnect and blank off the case breather for now and see what happened?
 
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L.A.B. said:
Nortasaki said:
I take advise from other Norton owners I trust and was told teeing this would be OK.

Can you outline what is connected and or blanked off is this a 750 with the breather at the rear of the crankcase originally with a modification of a breather from the timing side ? if so what does the modified timing side breather consist of ?

Paul :?:
 
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Nortaski,
When you say gushing oil (you mean leaking out into the atmosphere..?) or just up the breather?
Either way oil up the breather sounds like you have a wet sumped bottom end (your oil tank is draining into the timing & crank case) - read up on this topic much has been discussed :p
If oil is leaking out, it could be the breather is blocked (by oil ) perhaps? just guessing - I would check all your plumbing quite carefully before riding again. I only have the original breather and if my bike sits - it will pump oil back up the breather like a second return line :shock:
My timing cover and oil pump are in bubble wrap on the bench, they just went on a short holiday to Arizona. AMR added the spring ball to the timing cover and o-rings to the oil pump.
http://www.amr-of-tucson.com/nortech.html :D
Phil

ps - Taking another look at your photos: is your finger pointing to oil coming out from between the barrels and the case... is that the location of the gush? Sounds like you have a bad case of wet sump and need to reseal your barrels/case, looks like you don't have a base gasket, right? I have a similar geyser on the front.
 
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Been thru all this myself and IMHO the only way you can have oil p*****g out of the barrel base is if the cases are pressurised and there is no venting at all.
You capped off the original lower case breather but still added and teed the pipe. Why do that if it was sealed off?
If the XS breather is the right way round it sounds like the good old 'Combat' characteristic of oil being whipped around inside the cases and pooling at the rear leaving a void at the front where the return pickup is sited. On my original 'Combat' cases with slightly worn but not knackered rod journals the cases filled with oil above 4000 rpm and vitually emptied the tank in 10 miles. Under 4k no problem. I had the rear breather capped and an 850 style installed in the timing case with the 3 x 3/8" holes drilled. Strange thing is that even though the tank contents ended up in the cases and I have to guess the timing chest, it did not return up the 1/2" to 3/8"breather even with all that pressure. All it did was pee out the joints. The tank was vented to the airbox so explain that!!
I'm aware there are plenty of Combat owners out there who never had a problem and it seems with the original breather it just about works, the Norton OC tech notes state more oil went up the breather than via the oil pump return so there must be something in that. 'Fastback's' reply confirms that.
I think the rule is that if you mess/improve the breathing on a 'Combat' style motor with the lower breather you have to do the work on blocking the front pickup and opening up the rear as per Old Britts tech notes. Was this done on yours?
 
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plj850 said:
L.A.B. said:
Nortasaki said:
I take advise from other Norton owners I trust and was told teeing this would be OK.

Can you outline what is connected and or blanked off is this a 750 with the breather at the rear of the crankcase originally with a modification of a breather from the timing side ? if so what does the modified timing side breather consist of ?

Paul :?:


The timing side breather mod is just a fitting with hose to the xs650 breather valve teed with the original breather.
 
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Keith1069 said:
Been thru all this myself and IMHO the only way you can have oil p*****g out of the barrel base is if the cases are pressurised and there is no venting at all.
You capped off the original lower case breather but still added and teed the pipe. Why do that if it was sealed off?
If the XS breather is the right way round it sounds like the good old 'Combat' characteristic of oil being whipped around inside the cases and pooling at the rear leaving a void at the front where the return pickup is sited. On my original 'Combat' cases with slightly worn but not knackered rod journals the cases filled with oil above 4000 rpm and vitually emptied the tank in 10 miles. Under 4k no problem. I had the rear breather capped and an 850 style installed in the timing case with the 3 x 3/8" holes drilled. Strange thing is that even though the tank contents ended up in the cases and I have to guess the timing chest, it did not return up the 1/2" to 3/8"breather even with all that pressure. All it did was pee out the joints. The tank was vented to the airbox so explain that!!
I'm aware there are plenty of Combat owners out there who never had a problem and it seems with the original breather it just about works, the Norton OC tech notes state more oil went up the breather than via the oil pump return so there must be something in that. 'Fastback's' reply confirms that.
I think the rule is that if you mess/improve the breathing on a 'Combat' style motor with the lower breather you have to do the work on blocking the front pickup and opening up the rear as per Old Britts tech notes. Was this done on yours?

A blanking plate I ordered has been backordered, so I tried plugging the original tube with a bolt until I could get a blanking plate. The oil is coming out from behind the washer and nut holding the case together as shown in pic #2. I don't have it capped and teed. It is after I tried running with it from the timing case and it still leaked is when I tried it teed together with no positive results.
I don't think it is a combat, how would you know,being a Dunstall the head is stamped "M" modified where a combat is stamped with a "C". With engine number being 210105 it may be in a series where ther wet sumping may be an issue.
 
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Nortasaki said:
Keith1069 said:
Been thru all this myself and IMHO the only way you can have oil p*****g out of the barrel base is if the cases are pressurised and there is no venting at all.
You capped off the original lower case breather but still added and teed the pipe. Why do that if it was sealed off?
If the XS breather is the right way round it sounds like the good old 'Combat' characteristic of oil being whipped around inside the cases and pooling at the rear leaving a void at the front where the return pickup is sited. On my original 'Combat' cases with slightly worn but not knackered rod journals the cases filled with oil above 4000 rpm and vitually emptied the tank in 10 miles. Under 4k no problem. I had the rear breather capped and an 850 style installed in the timing case with the 3 x 3/8" holes drilled. Strange thing is that even though the tank contents ended up in the cases and I have to guess the timing chest, it did not return up the 1/2" to 3/8"breather even with all that pressure. All it did was pee out the joints. The tank was vented to the airbox so explain that!!
I'm aware there are plenty of Combat owners out there who never had a problem and it seems with the original breather it just about works, the Norton OC tech notes state more oil went up the breather than via the oil pump return so there must be something in that. 'Fastback's' reply confirms that.
I think the rule is that if you mess/improve the breathing on a 'Combat' style motor with the lower breather you have to do the work on blocking the front pickup and opening up the rear as per Old Britts tech notes. Was this done on yours?

A blanking plate I ordered has been backordered, so I tried plugging the original tube with a bolt until I could get a blanking plate. The oil is coming out from behind the washer and nut holding the case together as shown in pic #2. I don't have it capped and teed. It is after I tried running with it from the timing case and it still leaked is when I tried it teed together with no positive results.
I don't think it is a combat, how would you know,being a Dunstall the head is stamped "M" modified where a combat is stamped with a "C". With engine number being 210105 it may be in a series where ther wet sumping may be an issue.

Why not put up pictures of the whole run? from both ends of the "T" to the XS valve and where the XS valve goes.

Jean
 
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