Knocking / rattling inside primary drive case + backfire

concours · Feb 12, 2023

marshg246 · Feb 12, 2023

concours said:
View attachment 103732

Interesting! I didn't know about purple. The engine I'm working on now had red-looking everywhere but came apart OK so I knew it wasn't red and it definitely wasn't blue or green so I bet it was purple.

Mart UK · Feb 12, 2023

marshg246 said:
Interesting! I didn't know about purple. The engine I'm working on now had red-looking everywhere but came apart OK so I knew it wasn't red and it definitely wasn't blue or green so I bet it was purple.

Might have been one I'd worked on. If so, it was congealed blood mixed with sweat and tears.

BERT · Feb 14, 2023

It would be a good time to give the isolastics a check

baz · Feb 14, 2023

BERT said:
It would be a good time to give the isolastics a check

Unfortunately after seeing the way that primary was built
The whole bike will need checking
It's a fact that any bike is only as good as it's last owner
This is partly why Brit bikes get such a bad rap
And commandos in particular

M-Hawk · Feb 15, 2023

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.

baz · Feb 15, 2023

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.

Has all the clatter gone ?

KiwiShane · Feb 15, 2023

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.

Some photos would be helpful

marshg246 · Feb 15, 2023

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.

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,

marshg246 · Feb 15, 2023

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.

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.

KiwiShane · Feb 15, 2023

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,

I know thos may sound crazy...but is the inner primary slightly miss aligned ?

Mart UK · Feb 15, 2023

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.

concours · Feb 15, 2023

"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.

M-Hawk · Feb 16, 2023

baz said:
Has all the clatter gone ?

It won't run for long enough for me to find out.

M-Hawk · Feb 16, 2023

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,

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.

Great idea, thank you, I'll try that.

baz · Feb 16, 2023

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

M-Hawk · Feb 16, 2023

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.

marshg246 · Feb 16, 2023

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.

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.

M-Hawk · Feb 16, 2023

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.

Option 3 has become mandatory

marshg246 · Feb 16, 2023

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

You tighten the nuts to 15, not the studs! They should screw in all the way using fingers.