Right Exhaust on Mk3 Smoking After Engine Stop

Joined
Oct 17, 2021
Messages
1
Country flag
I have a 1975 Commando Mk3. The motorcycle runs really well. There is no visible smoke out of either exhaust while riding or while the engine is idling. The engine idles great it runs very smooth and strong. I have never had to add any oil and the engine has excellent compression. The spark plugs look great with no oil on either plug. The problem is that when I shut down the engine after it has been running more than 2 - 3 minutes, a large amount of smoke comes out of the right exhaust. No smoke comes out of the left side. It is a very light-colored smoke which continues to come out for about 3 - 5 minutes. I'm at a loss as to the cause. I've put around 500 miles on the bike since I purchased it and this has only developed recently.
 

Shelby-Right

VIP MEMBER
Joined
Jan 28, 2022
Messages
110
Country flag
It might be oil getting down from the valve guides , also if you do a big de-throttle down a hill ,ask your mates of there is a puff of smoke .cheers.
 

marshg246

VIP MEMBER
Joined
Jul 12, 2015
Messages
1,997
Country flag
It is a very light-colored smoke which continues to come out for about 3 - 5 minutes.
Blueish or white? Feel the inside of the muffler when cold - is it oilier than the other side? Does it do it after a longer run too? If the smoke is white, it may be condensation, but I can't imagine on only one side.
 
Joined
Dec 28, 2009
Messages
4,365
Country flag
Blueish or white? Feel the inside of the muffler when cold - is it oilier than the other side? Does it do it after a longer run too? If the smoke is white, it may be condensation, but I can't imagine on only one side.
Fit new Teflon intake guide seals . You likely will have to pull the head which is a big job. Don't use O.E.M. rubber seals.
 

Shelby-Right

VIP MEMBER
Joined
Jan 28, 2022
Messages
110
Country flag
I have done seal and spring changes mainly on cars with chainsaw pull rope, feed a good amount in then bring that cylinder to TDC , you might need to make a special lever and cut away pipe to assist in getting valve spring compressed , keepers out , pull that rocker shaft 1 st of course , might be worth a crack ? maybe someone who has had a go could chime in , otherwise its as torontonian suggests .
 
Joined
May 5, 2017
Messages
649
Country flag
I have a 1975 Commando Mk3. The motorcycle runs really well. There is no visible smoke out of either exhaust while riding or while the engine is idling. The engine idles great it runs very smooth and strong. I have never had to add any oil and the engine has excellent compression. The spark plugs look great with no oil on either plug. The problem is that when I shut down the engine after it has been running more than 2 - 3 minutes, a large amount of smoke comes out of the right exhaust. No smoke comes out of the left side. It is a very light-colored smoke which continues to come out for about 3 - 5 minutes. I'm at a loss as to the cause. I've put around 500 miles on the bike since I purchased it and this has only developed recently.
Please check your "conversations" [aka private messages]. Sign in and click the envelope icon at the top/right of any page. See posts #67 & 70 linked below for more info.

https://www.accessnorton.com/Norton...manual-parts-catalog-errors-2017.23083/page-4
 
Top