Sprocket/Tranny/Wheel Blocks in Neutral new/used Bandit 1200 motor

[icprey]

Hey Guys,

Decided to revive some old parts I've had laying around for a while.  Bought a used 1200 from what I consider a fair source a while ago but I know nothing about the engine.  I've never had a bad purchase from this guy before so didn't expect different this time. He claimed it to be a quality motor.

So I put a 7/12 together this week with that engine and just before clicking it into gear I was on my knees the bike on a rear stand and I decided to check chain to sprocket cover clearance (13/45 sprockets were already on the bike before the engine swap and worked fine before).  So weirdly after spinning the wheel around approx 3 full turns it came to a blockage stop.  Mechanically it is jamming against something.  And I have no reason to think it is behind the sprocket cover as it goes a full three wheel rotations around. And then you spin the tire in the opposite direction and it goes approx 3 rotations and again blocks up against something.

If I click it into gear 1 or 2 (not running) it reacts immediately as it is blocked from moving, practically no play, normal like.  Throw it back into neutral and it does the 3 rotations stops.  Reverse 3 rotations stops.  Weird. Never encountered this before.  Aside from the engine being an unknown, since I removed a weaping 1127 and placed the 1200 in there I had to make an 80mm clutch pushrod as the 1127 one was way too long.  If I went too short on that rod and the rod is "floating" for lack of a better word and without preload could that explain it?  Should it not be without preload?  Seeing as I am now petrified to start the motor in neutral or gear before figuring this out, I can't really say if the clutch rod is fully functional(I did start the motor after transplant in neutral without a sprocket or chain or wheel and the motor ran fine).

I'll add the sprocket cover obviously comes from a 750 Slabbie (6speed indicator 2 shaft holes), but really it fits like a glove.  Also I did look around at the rear wheel and chain to see if I could see it blocking anywhere, but being beside the sprocket and feeling where the block occurs it really  feels like its in the output shaft.  Did I buy a lemon and do all that work for nothing?  Any ideas engine/tranny guru's?  Thanks in advance if you can enlighten me on what this might be or where/how to look.

[Captain Chaos]

Hi and welcome on OSS. 

Remove the chain from the rear sprocket and spin the wheel, without spinning the output shaft if it still blocks you will know the problem is the rear wheel. 

My guess is a sprocket bolt or disc bolt that is too long/loose/otherwise touching the swingarm.

Edited April 23, 2020 by Captain Chaos

[Gixer1460]

7 hours ago, Captain Chaos said:

Hi and welcome on OSS. 

Remove the chain from the rear sprocket and spin the wheel, without spinning the output shaft if it still blocks you will know the problem is the rear wheel. 

My guess is a sprocket bolt or disc bolt that is too long/loose/otherwise touching the swingarm.

But the wheel spins three revolutions one way and will spin 3 back the other way - so it can't be a caliper / sprocket bolt! The weird thing is if the back wheel spins 3 turns then locks this would spin the output shaft approx 9 times in neutral ! Sounds like something is broken in the box - here endeth my knowledge of gearbox inner workings LOL!

[Captain Chaos]

Difficult to say but I read it as the gearbox shaft turns 3 revolutions either way until it blocks. With the gearing of 13/45 that means that the rear wheel spins almost one revolution.

EDIT you're right, just re-read the story while not at work, with a clear mind. Ignore my diagnosis then

Edited April 23, 2020 by Captain Chaos

[icprey]

So I hate posts where the OP doesn't come back and tell you what finally happened or the fix.  Not going to do that here. This could save someone some grief later on.

But I'll have a little fun giving you the answer.   So there was an 1127 in there before.  The 1200 was set-up with the same sprocket cover and sprockets and chain and wheel as when the 1127 was in there and the only change being the Bandit 1200 engine.  So where is the difference in all of this to cause the problem????  Did I give you enough info before for the most astute?  Well I didn't catch it even though in hindsight I should have known this.

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As has likely been covered here before the changes to the Bandit externally are pretty limited. Seemingly they are the same exterior dimensions and certainly the 1100 L,M,N models are but not the K.  Anybody see where I am going with this yet????

Yup the output or countershaft is further out on those models(L,M,N & Bandit).  Mix that with a fairly aggressive master link and an Slabbie Sprocket Cover and you have an interference.  The sprocket is spaced outwards more on the Bandit than the 1127K engine was to clear the 5.5in. wheel and therefore the Master Link was out further contacting the edge of the slave cyclinder.  So turn the rear wheel several rotations the master contacts the slave from above turn it in the opposite direction several rotations and the master hits from beneath.  I watched chain and sprocket through the holes clear everything in front of the chain, but i could not see this happening side inside.  Worst part is that I recently found out the sprocket covers receive a new part number with the 1127L motor and likely they clearanced around this area just for that. Comment if you know.

Anyways a little grinding and we are all good with that for now. All excited I tried to start her up and throw into gear and of course it seems a plug went and fouled so I'll have to confirm the clutch rod length another  time.  THX for making me get back on my knees and pull the cover just to be sure!  Pictures speak volumes.

[vizman]

Riddle me this... waiting rooms full of kids with pans stuck on their heads.....some make it to adulthood 

[Blubber]

In short:

The master link caught the casing?

[fatblokeonbandit]

what is "a fairly aggressive master link "..?????

Edited April 24, 2020 by fatblokeonbandit

[vizman]

There’s a spacer that sits on the output shaft....they come in different lengths.....always measure your head and the pan before sticking the pan on your head.

[vizman]

Link no worky 

[icprey]

Hey guys,

I had pulled the sprocket  off both engines and put them back as is, so no shim or spacer that I know of was there other than the big one that goes into the cases on the countershaft.

I know, "aggressive masterlink", what's that.  I'll add a couple of example pics, but I have used several types in the past. Regular style with a locking clip, press fit ones that need the ends mushroomed and then there is this thing.  It is a press fit outer plate that needed press fit type install power but the roller rods extend out about twice the typical distance and has e-clips on it as a just in case scenario.  Nothing sleek about the outside of this thing.  

In the pics one protrudes very little while the next one (mine does not stick out quite that far, but more than a typical clip type) would have alot more outside length.  And that added to the countershaft extra length is where things went tok tok against the cover.