1974 norton 850 mk wont start!!! help!

Status
Not open for further replies.

flanker850

Joined
Feb 6, 2012
Messages
47
Hello all! I have 4 ducatis old and new. I restored a 1965 monza with some success. I just got a 1974 norton commando. I have always admired the commando as a kid and jumped at the chance to get one. As soon as i got it, it did not kick over. I replaced the battery (no fluid at all), i replaced all the fluids possible, except the swing arm. changed both plugs. removed the gas from the tank and filled with new. I removed the fluid from the single mikuni carb. The plugs get a spark when you put them in next to the cylinder and kick over and the compression is strong. horn and lights work well. signals were removed by prior owner but rear light is working. boyer ignition seems to be attached. prior owner said it was running fine a year ago. Any suggestions???? I would appreciate any help!!! im in los angeles. the front brake master cylinder is leaking break fluid, so irodered replacement seals from brit bike in nj. so i cleaned the adjacent controls which had mild corrosion with air. thx tons Rob
 
OH, Boy, a new victim. Ignition needs spark (which you apparently have), fuel (which you didn't address) and compression (which you did address) and then there is the timing issue. I'll leave it to the Boyer Boys.

I'd go here first. http://www.jba.bc.ca/Bushmans%20Carb%20 ... l#1REBUILD

Welcome to the world of torque.

Dave
69S
 
DogT said:
OH, Boy, a new victim. Ignition needs spark (which you apparently have), fuel (which you didn't address) and compression (which you did address) and then there is the timing issue. I'll leave it to the Boyer Boys.

I'd go here first. http://www.jba.bc.ca/Bushmans%20Carb%20 ... l#1REBUILD

Welcome to the world of torque.

Dave
69S
Click to expand...

thx i'll check the carb now. i drained the old fuel from the tank and carb and out new fuel in!!!! to no avail. when i kick it over nothing. i even tried a pop start and it it kinda wated to kick over 2x, but never really camer around, so you think i need to tune carb? ok i'll try it. anything else? thx tons
 
Mikunis seem to gum up easier than any other carb if lkeft to sit.

Go down to the corner auto supply and buy a one-gallon bucket of Berryman's Chem Dip and dip all the metallic carb parts for 30 minutes. Flush really well with water and blast dry with compressed air.

Install a fresh set of spark plugs.

Should fire with a PROPER (stout) kick.

Probably won't have to, but you might check the valve lash...
 
make sure you have a full battery as boyers do not like low battery volts and will cause all kinds of problems including lifting you off the kickstarter. Also the connectors (old points wires) can give trouble.

Try a little fuel straight in the sparkplug hole.

Good luck
Peter R
 
I didn't see the mukunis thingie. I tend not to see that. I'll leave it to the experts.
 
bluemax said:
make sure you have a full battery as boyers do not like low battery volts and will cause all kinds of problems including lifting you off the kickstarter. Also the connectors (old points wires) can give trouble.

Try a little fuel straight in the sparkplug hole.

Good luck
Peter R
Click to expand...
thx i have a brand new battery and plugs. so pous gas into spark plug hole??? you guys are amazing!!!! i really appreciate the help!
 
grandpaul said:
Mikunis seem to gum up easier than any other carb if lkeft to sit.

Go down to the corner auto supply and buy a one-gallon bucket of Berryman's Chem Dip and dip all the metallic carb parts for 30 minutes. Flush really well with water and blast dry with compressed air.

Install a fresh set of spark plugs.

Should fire with a PROPER (stout) kick.

Probably won't have to, but you might check the valve lash...
Click to expand...

cant wait to try this!!!!! just clean the carb basically???
 
ok you guys i put a little fuel in the sparks plug holes and it started to kick over!!!! does that mean the carb is gunked up???? thanks so much!
 
Oh one more thing Mikuni's need choke to start, at least mine does, and if no choke used when cold then any opening (and I mean any) of the throttle and it will refuse to fire at all and i mean nothing.
Make sure the choke lever is down.

Cheers
peter R
 
bluemax said:
Oh one more thing Mikuni's need choke to start, at least mine does, and if no choke used when cold then any opening (and I mean any) of the throttle and it will refuse to fire at all and i mean nothing.
Make sure the choke lever is down.

Cheers
peter R
Click to expand...
yep lever down! I think i have to clean the carb??? right?
 
bluemax said:
Oh one more thing Mikuni's need choke to start, at least mine does, and if no choke used when cold then any opening (and I mean any) of the throttle and it will refuse to fire at all and i mean nothing.
Make sure the choke lever is down.

Cheers
peter R
Click to expand...
yeah i dont think the carb is getting fuel because the bike does not stay running, but its so great to hear it run.... even a little. i think im hooked
 
sounds like you have a plan.
When you have the mikuni off check to see if the two socket screws inside the manifold are tight. Have a look at my previous post "things you find in strange places" very scarey.
If they are at all loose, loctite them in!

How about posting a pic of your bike.

Cheers
Peter R
 
Hey Flanker,
Start at the top.
Check that the fuel taps are allowing fuel through, then the inline fuel filter if you have one, then the line itself.
Remove the the "float bowl drain plug" (17mm ring spanner) to see if the float needle is allowing fuel into the bowl.
If you are getting fuel into the bowl and it still doesn't start, then the Idle jet is probably blocked, and or the Choke is not
working properly........... It goes on and on.
Do what Paul said, or just clean everything fastidiously, then blow it out with air. If you'r gonna use air on the jets, hang onto
them carefully because if you loose one.......
Look carefully at the carb while you are pulling it apart, there are airways and jets at the rear and inside, remember where
everything goes.
A Mikuni does not require any throttle when useing the Choke (enricher circuit) to work properly, However if the Carb is not
set up quite right then it may work better with some throttle.
Clean it all up, she'll go.
AC.
 
I have to thank everyone for all the aid!!!! I followed the advice....and what do you know??? It started and now no issues with kicking it over and idling!!! of course this new turn of events brings out other probs!!! cheers and thx, rob
 
That's not surprising. But we really want to know the whole procedure. Don't keep us in the dark. After all, we all learn from this.

Dave
69S
 
OK the bike starts up super well and sounds great!!! I have some shifting issues that I alluded to earlier. most specifically, i can go down to 3rd and 4th but coming back to 1st and neutral does not happen. it truly freezes up. So the advice i got was was to check the chain, clutch and gearbox. the chain seems sorted. so i decided to tear into the gear box first. i also bought barnett clutch plates to replace the stock. i plan on doing that tomorrow.....

THE GEARBOX
I removed the inner and outer covers. The gears looked pretty good. no issues with the shaft and the i went though the gears pretty well by rotating the wheel and moving the quadrant. So i oiled/cleaned what i could and put it back together. Well sort of.... the whole thing went back together and i was rolling, but the outer box will not slide into the ratchet plate when it is connected to the knuckle pin roller/ quadrant. The outer cover fits without the ratchet plate and the knuckle ratchet plate and neighboring rod connect well.

The spring is pretty twisted I need a new one.

My question is can the ratchet plate be bent? or is there some trick to getting the outer cover back on. I was thinking heat, but it should fit right. im certain the pawl is in place and not blocking reassemble. The ratchet plate goes halfway into the outer cover and refuses to go any further. any ideas????? Rob
 
Status
Not open for further replies.
Back
Top