Knocking / rattling inside primary drive case + backfire

Status
Not open for further replies.
Quick update:

Clutch locking tool arrived. Rotor nut is now torqued at 70ft lb.

Electrical gremlin has re-surfaced. Bike started but cuts out as soon as I give it any throttle. On inspection, twisting the throttle seems to kill the electrics. Must be a loose connection somewhere in the bar electrics. Weird one. I'll have another look at the bar electrics.

Stator won't mount on the 3 new stator mount studs. Only goes on the 2 studs nearest the front of the bike, not the 3rd and uppermost stud. I replaced all 3 studs with brand new (twice), and none are overtightened so it seems that the threads are very slightly misaligned. If I mount the stator on 2 studs, then introduce the 3rd stud it goes in OK but I'm left with a big stator gap at one side, and an almost touching gap on the other side. I'm guessing the top right stud thread has been cross-threaded at some point in it's life, and re-tapped, or is still cross threaded. I'm tempted to bend the other 2 slightly to meet it, and hopefully correct the stator gap but that doesn't feel very scientific at all. Bit stuck on this one.
 
M-Hawk said:
Quick update:

Clutch locking tool arrived. Rotor nut is now torqued at 70ft lb.

Electrical gremlin has re-surfaced. Bike started but cuts out as soon as I give it any throttle. On inspection, twisting the throttle seems to kill the electrics. Must be a loose connection somewhere in the bar electrics. Weird one. I'll have another look at the bar electrics.

Stator won't mount on the 3 new stator mount studs. Only goes on the 2 studs nearest the front of the bike, not the 3rd and uppermost stud. I replaced all 3 studs with brand new (twice), and none are overtightened so it seems that the threads are very slightly misaligned. If I mount the stator on 2 studs, then introduce the 3rd stud it goes in OK but I'm left with a big stator gap at one side, and an almost touching gap on the other side. I'm guessing the top right stud thread has been cross-threaded at some point in it's life, and re-tapped, or is still cross threaded. I'm tempted to bend the other 2 slightly to meet it, and hopefully correct the stator gap but that doesn't feel very scientific at all. Bit stuck on this one.
Click to expand...
Has all the clatter gone ?
 
M-Hawk said:
Quick update:

Clutch locking tool arrived. Rotor nut is now torqued at 70ft lb.

Electrical gremlin has re-surfaced. Bike started but cuts out as soon as I give it any throttle. On inspection, twisting the throttle seems to kill the electrics. Must be a loose connection somewhere in the bar electrics. Weird one. I'll have another look at the bar electrics.

Stator won't mount on the 3 new stator mount studs. Only goes on the 2 studs nearest the front of the bike, not the 3rd and uppermost stud. I replaced all 3 studs with brand new (twice), and none are overtightened so it seems that the threads are very slightly misaligned. If I mount the stator on 2 studs, then introduce the 3rd stud it goes in OK but I'm left with a big stator gap at one side, and an almost touching gap on the other side. I'm guessing the top right stud thread has been cross-threaded at some point in it's life, and re-tapped, or is still cross threaded. I'm tempted to bend the other 2 slightly to meet it, and hopefully correct the stator gap but that doesn't feel very scientific at all. Bit stuck on this one.
Click to expand...
Some photos would be helpful 👍
 
M-Hawk said:
Stator won't mount on the 3 new stator mount studs. Only goes on the 2 studs nearest the front of the bike, not the 3rd and uppermost stud. I replaced all 3 studs with brand new (twice), and none are overtightened so it seems that the threads are very slightly misaligned. If I mount the stator on 2 studs, then introduce the 3rd stud it goes in OK but I'm left with a big stator gap at one side, and an almost touching gap on the other side. I'm guessing the top right stud thread has been cross-threaded at some point in it's life, and re-tapped, or is still cross threaded. I'm tempted to bend the other 2 slightly to meet it, and hopefully correct the stator gap but that doesn't feel very scientific at all. Bit stuck on this one.
Click to expand...
Didn't it go on the old studs?

IMHO, four reasonable fixes. 1) Open the holes in the stator. I've never had to do that. I've Opened just the entry (backside) several times but never all the way through. I use a cheap tapered hand reamer. Some people drill but when I've tried that the bit spread the layers of metal and destroyed the stator. 2) Try the spacers in diferent locaitons. 3) Get the stator on, snug it, and hit it with a hammer (not hard) in the direction it needs to go then tighten (often do this but only is off a little). 4) New inner primary (expensive).

If you work in that order, you may find a combination of things that work,
 
M-Hawk said:
Quick update:

Clutch locking tool arrived. Rotor nut is now torqued at 70ft lb.

Electrical gremlin has re-surfaced. Bike started but cuts out as soon as I give it any throttle. On inspection, twisting the throttle seems to kill the electrics. Must be a loose connection somewhere in the bar electrics. Weird one. I'll have another look at the bar electrics.
Click to expand...
Your kill button has a White with Yellow stripe (White/Yellow) wire and a White Wire. Find the switch console cable that has those two. Unplug them. Leave the ones from the switch console dangling and connect the other two together - white is "hot" and White/Yellow is ignition power but there may be more colors involved depending on your ignition system. Regardless, connecting the white and the wire the white/yellow was connected to will eliminate the kill button.
 
marshg246 said:
Didn't it go on the old studs?

IMHO, four reasonable fixes. 1) Open the holes in the stator. I've never had to do that. I've Opened just the entry (backside) several times but never all the way through. I use a cheap tapered hand reamer. Some people drill but when I've tried that the bit spread the layers of metal and destroyed the stator. 2) Try the spacers in diferent locaitons. 3) Get the stator on, snug it, and hit it with a hammer (not hard) in the direction it needs to go then tighten (often do this but only is off a little). 4) New inner primary (expensive).

If you work in that order, you may find a combination of things that work,
Click to expand...
I know thos may sound crazy...but is the inner primary slightly miss aligned ?
 
Don't think the inner primary affects it, does it? The spacing of the shaft and the stator mount studs are set by the engine case, which go through the inner primary. That's how it is on my Mk3, so apologies if earlier models are different.

With it on all 3 studs, are you able to get the correct spacing before it's all tightened up? I've read somewhere of using an old plastic bottle (e.g. washing up liquid), cut up to provide a 360 degree spacer while you then tighten the stator down. Then slide the spacer out.
 
"Electrical gremlin has re-surfaced. Bike started but cuts out as soon as I give it any throttle. On inspection, twisting the throttle seems to kill the electrics. Must be a loose connection somewhere in the bar electrics. Weird one. I'll have another look at the bar electrics."

Statistics show, that 99% of all carburation problems are electrical in nature. 💡
 
marshg246 said:
Didn't it go on the old studs?

IMHO, four reasonable fixes. 1) Open the holes in the stator. I've never had to do that. I've Opened just the entry (backside) several times but never all the way through. I use a cheap tapered hand reamer. Some people drill but when I've tried that the bit spread the layers of metal and destroyed the stator. 2) Try the spacers in diferent locaitons. 3) Get the stator on, snug it, and hit it with a hammer (not hard) in the direction it needs to go then tighten (often do this but only is off a little). 4) New inner primary (expensive).

If you work in that order, you may find a combination of things that work,
Click to expand...
I changed the studs because one had a stripped thread and I had a stator alignment issue that I thought must be down to slightly bent studs.

Now the stator isn't seating easily on the 3 studs, just 2. I can get the stator to mount if I remove 1 stud (the top right one), fit on the other 2 and then introduce the 3rd stud through the stator hole and into the stud thread. I'm pretty sure there's some cross-threading going on here. When I do it this way I can get the stator to mount, and I'm left with a gap to rotor from 10 o'clock to 1 o'clock and the stator is tight on the rotor at the opposite side 4 o'clock to 8 o'clock. I've tried moving the spacers which made no difference, and I don't think bigger stator holes will help this particular problem. So I think I'm going to try the gentle hammer approach (option 3). When mounted it's not out by much to be honest.

Mart UK said:
I've read somewhere of using an old plastic bottle (e.g. washing up liquid), cut up to provide a 360 degree spacer while you then tighten the stator down. Then slide the spacer out.
Click to expand...
Great idea, thank you, I'll try that.
 
When you finally get the alternator fitted
Try turning the the engine over and checking the air gap in many positions
The shimming of the centre mounting stud on the inner chaincase can affect the alternator rotor clearance
But not the stator fit on the 3 studs
Maybe take the 3 alternator studs out and take a look at the stud mounts for damage
Sometimes the poles that the studs mount to get damaged if an alternator rotor has let go in the past
 
Last edited:
Another day, another disaster…

I was tightening one of the studs to 15ft lb and the post has split. It really didn’t take much pressure at all.

I guess I’m now in the market for an inner primary casing. Sigh.

On the upside, there was clearly an issue with one or two of the posts which was causing misalignment issues anyway.

Knocking / rattling inside primary drive case + backfire
 
M-Hawk said:
I changed the studs because one had a stripped thread and I had a stator alignment issue that I thought must be down to slightly bent studs.

Now the stator isn't seating easily on the 3 studs, just 2. I can get the stator to mount if I remove 1 stud (the top right one), fit on the other 2 and then introduce the 3rd stud through the stator hole and into the stud thread. I'm pretty sure there's some cross-threading going on here. When I do it this way I can get the stator to mount, and I'm left with a gap to rotor from 10 o'clock to 1 o'clock and the stator is tight on the rotor at the opposite side 4 o'clock to 8 o'clock. I've tried moving the spacers which made no difference, and I don't think bigger stator holes will help this particular problem. So I think I'm going to try the gentle hammer approach (option 3). When mounted it's not out by much to be honest.
Click to expand...
OK, since the stud screws in with stator in place, you are probably right about the cross threading. After you have it screwed in , see if you can remove and re-install the stator. If so, you know it is the threads and you have three ways to go that I can think of:
1) If it seems solid, unscrew it, put the stator back on, and then the stud with blue locktite. Make sure the stud goes in tight. Remove the stator and cleanup. Then go back to working on getting the stator gap.
2) Take it all back apart and helicoil that hole using either an accurate drill press or mill, or pilot drilling through the stator to get a straight hole.
3) Replace the inner primary.
 
marshg246 said:
OK, since the stud screws in with stator in place, you are probably right about the cross threading. After you have it screwed in , see if you can remove and re-install the stator. If so, you know it is the threads and you have three ways to go that I can think of:
1) If it seems solid, unscrew it, put the stator back on, and then the stud with blue locktite. Make sure the stud goes in tight. Remove the stator and cleanup. Then go back to working on getting the stator gap.
2) Take it all back apart and helicoil that hole using either an accurate drill press or mill, or pilot drilling through the stator to get a straight hole.
3) Replace the inner primary.
Click to expand...
Option 3 has become mandatory :(
 
M-Hawk said:
Another day, another disaster…

I was tightening one of the studs to 15ft lb and the post has split. It really didn’t take much pressure at all.

I guess I’m now in the market for an inner primary casing. Sigh.

On the upside, there was clearly an issue with one or two of the posts which was causing misalignment issues anyway.

View attachment 103930
Click to expand...
You tighten the nuts to 15, not the studs! They should screw in all the way using fingers.
 
Status
Not open for further replies.

Similar threads

Bonzo
  • Locked
Low knocking/clonk coming from primary chaincase area?
2
Replies
24
Views
2,824
Bonzo
Bonzo
S
  • Locked
Strange knocking noise when releasing the clutch
2
Replies
20
Views
5,227
SteveBorland
S
Nortorious
  • Locked
Knocking in the primary case
2
Replies
23
Views
5,192
gortnipper
gortnipper
M
  • Locked
New Norton knocking help please
2 3 4 5
Replies
90
Views
15,513
maylar
maylar
Balmain Bill
  • Locked
Anti backfire gear wear
Replies
11
Views
2,790
KiwiNeill
K
Back
Top