Norton Motorcycle Tech Talk

Home

Printer-friendly copy
Online Resources
Norton Manuals / Dyno Dave / MotoCycles.com / Daytona Bike Week
Top Norton Motorcycle Tech Talk Forum Topic #534   Previous topic | Next topic   
ccs1601Sun Jun-15-08 05:56 PM
Member since Mar 18th 2009
9 posts
Click to send private message to this authorClick to view this author's profileClick to add this author to your buddy list
"oil leak"
Sun Jun-15-08 06:01 PM by ccs1601

  

          

My 1972 combat commando recently developed a new oil leak. I started to notice drops of oil on the toe of my right boot after a long ride and it has become progressivly worse over the last month. I had a hard time finding the source. I have never seen a drip while it was happening and the engine seems completely clean and dry but my best guess is that there may be some oil collecting on the cooling fins between the exhaust pipes at the level of the head gasket. When I hit a certain speed the wind blows drops off the fins landing on my right toe or the timing cover. The engine was rebuilt 3000 miles ago with modern ugrades including the head gasket. I assume (but cannot verify) that the previous owner who was a norton mechanic retorqued the head at the proper mileage after the rebuild. I have put a few hundred miles on the engine myself. My thought is that the oil is leaking out of the head gasket from one of the pushrod tunnels. The leak isn't bad. I don't mind the oil on my shoe. Should I leave everything alone or try to fix it? I'm thinking of retorqing the head gasket (never done one before but there is a first time for everything). Good idea or bad? Maybe I should just tighten the bolts at the front of the motor since thats the only area with trouble. If I decide to retorque the whole thing should I loosen all the bolts and nuts first and then tighten them all back up ( I have a shop manual that gives the proper order and torques) or do I just back off each one a half turn and retorque one at a time going in order from first to last? Right now my bike runs perfectly and I don't want to make things worse but there is no local mechanic willing to work on this antique, at least none that wouldn't be working on it for the first time same as me so I'm pretty much on my own with this thing. I would appreciate any and all help.

  

Alert Printer-friendly copy | Reply | Reply with quote | Top
johnandnzMon Jun-30-08 12:06 AM
Member since Mar 18th 2009
33 posts
Click to send private message to this authorClick to view this author's profileClick to add this author to your buddy list
#1. "RE: oil leak"
In response to Reply # 0


  

          

Yes I would retorque the head.

Back off each one by one and retorque. I would do all of them. You may find it difficult to get a spanner to fit on the nut at the back of the cylinders below and between the carb. You will not be able to get a torque wrench on it and will have to tightening up by "feel" unless you rig up some lever and spring balance system. You may also need to obtain slim sockets to reach the nuts down in deep holes on the top of the head.

  

Alert Printer-friendly copy | Reply | Reply with quote | Top

ccs1601Sun Jul-13-08 07:36 AM
Member since Mar 18th 2009
9 posts
Click to send private message to this authorClick to view this author's profileClick to add this author to your buddy list
#2. "RE: oil leak"
In response to Reply # 1


  

          

Thank you. Now my problem is wrenches. I have sockets that fit the nuts and a torque wrench but it is impossible to reach the bolts under the exhaust ports as well as the one at the back of the head under the intake ports. The head of the torque wrench is too bulky. I have searched the internet and found a "break over" wrench with interchangeable box wrench heads. Would this do the job? It reguires a separate torque calibrater to set the break over tension. Is there an easier way? Where can I buy what I need. Thanks for the help.

  

Alert Printer-friendly copy | Reply | Reply with quote | Top

dynodaveSun Jul-13-08 08:12 AM
Member since Mar 18th 2009
706 posts
Click to send private message to this authorClick to view this author's profileClick to add this author to your buddy list
#3. "RE: oil leak"
In response to Reply # 2


  

          

The rear head nut is tightened with a 5/16W box wrench.
The box usually has to get thinned down.
a set of calipers to measure and evanly thin the wrench around the outside works better than eyeballing it.
commandos seem to handle a thicker box wall than earlier atlas' etc.
Mine of course is now atlas thin and is still plenty strong for commando use.

The typical 6-8" long wrench...grabbed on the main part of the handle and then pulled with one hand only until it is quite painful is about the torque required. I tested this method using a torque wrench to develope the feel required.
Not 100% scientific.... but I have never heard the factory actually used a torque wrench......more rumor and wifes tails say it was done by hand.

  

Alert Printer-friendly copy | Reply | Reply with quote | Top

Top Norton Motorcycle Tech Talk Forum Topic #534 Previous topic | Next topic





Norton Commando Oil Change