First ride issues to ask the experts!

So I did a bunch of "winter work" on my Norton and yesterday was the first ride. I chose to take it to work and back just to see if it is running well. Although the ride to work was perfect, no leaks no issues at all. The ride home I had a few struggles.

On the way to work it was 65 degrees outside. On the way home it was 90 degrees outside. The bike sat for 9 hours between the rides. The route is canyon 34 miles. decline and incline....


On the way home I noticed that the idle was climbing, it went to a normal 1000rpm to just under 2000rpm. It was mildly annoying. Also towards the last mile I noticed the primary started leaking.

Primary: I drained and refilled this prior to the ride with ATF to the drain screw. When the leak formed I noticed the fluid was not red but a max of red and brown, I am thinking some of the trans fluid pushed into the primary.

Idle: After getting home I took the carb out and filter and inspected it for any blobked idle screw or junk in the bowl (single Amal). I blew out the thing and the filter as well and put it back together.

I looked at the rubber carb mount from the intake manifold and it looks really good, no cracks or anything. I also removed the plugs and saw that they looked a little rich but not wet. I changed them.


This morning I chose not to ride in to work again but I couldnt leave without firing the bike up in my garage. It kicked on first kick with choke on and after about 10 seconds I closed the choke and it idled perfect at 1000rpm. I sat there scratching my head thinking of what to do to attack this. Well today I have been scouring the boards looking for trans to primary leaks, primary leaks, and stuff but all i see is "run it dry with a belt" threads.... I would like to run it dry but I think my issue is fluid coming from the trans to the primary.

Primary: I would say more of a crank seal leakage is suspect. What type of reed valve do you have, or should I say, do you have an reed breather valve and where is it placed. Check for air flow out the breather tube with bike running.

Idle: Idle cold with the choke off is sooo much different than idle when hot. Set Idle hot. It does not seem that you are leaning out when hot so it must be a simple matter throttle stop screw.

pvisseriii said:

Primary: I would say more of a crank seal leakage is suspect. What type of reed valve do you have, or should I say, do you have an reed breather valve and where is it placed. Check for air flow out the breather tube with bike running.

I put a xs650 reed valve on it this winter. This and new valve cover gaskets and tach drive gasket and primary gasket, I am happy I stopped the tach and valve cover leaks but that primary is getting either oil or trans fluid into it. I also changed the felt seal last year from the crank to primary... The reed valve is next to the battery about 15 inches from where the line comes out of the case. I will have to check the airflow when i get home...



Idle: Idle cold with the choke off is sooo much different than idle when hot. Set Idle hot. It does not seem that you are leaning out when hot so it must be a simple matter throttle stop screw.

Click to expand...

I was adjusting idle after the bike gets warm but I guess I may not have been waiting too long. I would ride it in front of my house and let it idle a bit but this climbing idle happened after riding for 20 min in the afternoon at 90degrees. The morning I rode in 34 miles without idle isues when i arrived to work, thats why I was thinking the bike should be warm enough and running fine.

Thanks for the input, I appreciate it.

Felt seal on the crank?

Sticky slide? Things got mighty hot back there. When you slap the throttle will it settle down? Do you have play in the cable?

I'm sorry not in the crank on the clutch side, http://www.oldbritts.com/1971_g8.html "#4" It was actually a couple years ago it was done.



When I took the carb apart there wsas tons of carbon and it was pretty dirty. The slide was the most funky looking but it wasnt sticking. I took a while and cleaned it before reassembling it back together.

Are you using points ignition?

Often the AAU is the problem. The cam for the bob weights wears irregulary. When they wear out, at idle the advance bob weight cams tend to climb into the wear divit and gradually advance the ignition.

its points alright.

Im gonna have to get on the thing today after work and get it hot then mess around. after that ill go to the garage and work on the bike.

I guess by what you say that you appear to be running rich and after a good run it will carbon up the slide enough to where it t may stuck a little. Best guess.


Some have had issues wnwre on short runs where the bike does not get hot and consolidation will develope in the reed. Kind of like playing a sax with a mouth full of 50 weight. You may want to check that out.. Wet sumping(God forgive me for mentioning it) will push oil up there to. This will cause crank pressure and blow out the crank seal...

Just throwing stuff out there.

Well I put the questions out there for you guys to throw what you can back, I appreciate the input greatly. I will go home today and check this stuff out and most importantly ride the bike a while first.

So I got home and did some working on the Idle. I ran the bike for about 5 miles and got it to idle high when hot. Then I went home and adjusted the throttle adjustment back to nothing on top of the carb. The idle was still high. Then I adjusted the pilot air screw till the bike was very low idle. After that I re adjusted the throttle adjustment a little and it's idling good again when hot. It also starts as well and accellerates great too.


I also took the return hose for crankcase presure off the oil tank. I did this while idling and the pressure is pushing and not sucking so the xs650 valve seems to be doing its job. One thing I did notice is that oils sputtering out. Does this mean I have wet sumped or is it normal? The oil level in the oil tank is below the L mark. Seems lots of people are ademant about the oil dipstick being wrong on these bikes.

Now I will be placing a ink park on the oil dipstick to see how much oil i lose to the primary...

Thanks again for your input, I appreciate it.

iceteanolemon said:

Then I adjusted the pilot air screw till the bike was very low idle. After that I re adjusted the throttle adjustment a little and it's idling good again when hot. It also starts as well and accelerates great too.

Click to expand...

Yes, it is most certainly a dance between the two screws.

I also took the return hose for crankcase pressure off the oil tank. I did this while idling and the pressure is pushing and not sucking so the xs650 valve seems to be doing its job. One thing I did notice is that oils sputtering out. Does this mean I have wet sumped or is it normal?

Click to expand...

More than likely. But you must remember, most will wet sump. Wet sumping is (but not absolutely) common in most dry sump systems and not exclusive to Nortons by any means. This issue is very individualistic and handled in many ways. As I am sure you have read, the topic is lengthy, spirited and seemingly endless, no.....not seemingly endless, truly endless. If you ask me what i do, make sure it is in a private message or like bees to honey, they'll latch on to your thread and it will be a hostile take over for sure. :cry:

The oil level in the oil tank is below the L mark. Seems lots of people are adamant about the oil dipstick being wrong on these bikes.

Click to expand...

There is some leeway there, as long as there is not too much or too little oil in the tank. :lol: (seriously)

Now I will be placing a ink park on the oil dipstick to see how much oil i lose to the primary...

Thanks again for your input, I appreciate it.

Click to expand...

Sounds like you're getting a real feel for it all. Good Going!

Been through this a lot last year on my stock Combat. Suspect worn carb slides, as no other air leaks or clogs found. Balance tube and float bowls checked on each ride too. I'd most suspect the AAU is sticking advanced more when more heat soaked. You can check on this by seeing if dragging engine down in low gear w/o throttle by brake drag, then stop and see if is idles low and steady or creeps but up too high. Them AAU's are a real pain as I've a handful now and some have springs that don't pull the adv back with any tension. I found I can lube the AAU w/o disturbing timing but just undoing the bolt, tapper fit holds it tight, then pull the snout out some and squirt heavy oil in it - with a rag under to collect the over flow. Yet when contact breaker and AAU are nice functioning its such a one step on starter and nice response compared to most the electro brain sparkers, especially the Black Box Boyer. Warmed up means theres some heat soak to carbs so they are hot to finger tips. Dang plugs then to foul while diddling the tune, so keep swtiching those - if last correction attempt of something else failed. I've got like 3 pair out of a V8 box that I'm pretty sure are fine but didn't know if adding to my hi idle or hard starts, till something else fixed so will clean em and try em then store on or off bike till needed again.