1984 Katana 7/11

[SVSooke]

Hmmmmmm..............if the bolts aren't factory the yellow probably isn't either,in in other words I have no idea

[pete]

I should've said that the cams are definitely genuine factory items... exhaust has the tacho drive and EX marked and the inlet has IN marked... I think the answer really is going to be measuring and/or comparing to a known stock set and seeing if they've been ground.

John loaned me a bunch more of his tools so I'll be able to do that at some point as well as degree them as much as non-slotted sprockets will allow me to.

And on to take two of the measurements...

Firstly the cylinders, and providing I'm reading the micrometer correctly, 6 different places in all four cylinders measure between 2.834" and 2.836" which is still in spec (service limit 2.8378"). I know it's probably getting a bit close but I don't think it needs a bore.








And measuring the pistons again has them all pretty much the same at 2.832" which is well above the service limit (2.8299").








That also gives the piston to cylinder clearance as 0.002 to 0.004" which is less than the service limit (0.0047") so I think that means I'm pretty good to go and just a hone and new rings will do the trick.


I've yet to check the wrist pins out though.


Then I grabbed out the wire wheel, bench mounted the drill, and went to work on the valves.





7 done, 9 to go, looking much better! I can never work out how clean underneath should be so I've just focused on making sure the edges are clear. I'll likely come back and clean the rest off also.


To my uneducated eyes they look like they won't need facing either which is another bonus.











I took out the selector forks and drum as well to get prepared for cleaning up the outside and repairing that broken post but I left the bearings in there for the moment.


Any thoughts on replacing those? They're not ridiculously expensive I suppose but $90 for the pair starts adding up.


They both feel good to me... of course the big question really is can I leave them in there while getting the cases prep'd for paint? I'm not sure if I'll do it myself yet or if I'll get them blasted...

[John Kat]

The cost of new piston rings will scare you.
On my GS 1000 S it ended up cheaper to go for a 4 new Wiseco pistons...

[pete]

Just priced them up locally, $60 each for a set so $240 all up is a lot cheaper than a set of pistons over here I would think... all the Wiseco kits I've seen have been $800+...

As for leaving the selector drum bearings in, looks like as long as I protect them well they should be fine.

I did some more measuring last night. Sat the clutch basket back in and measure the backlash on the primary gears and, well, I couldn't really even see the needle move on the dial gauge so either I'm doing it wrong or it's well within spec.


I sat the base of the dial gauge in the middle of the crank case and adjusted the arm to have the post of the gauge just sitting on one of the primary drive's teeth. Then I held the clutch basket firm while trying to wiggle the drive gear and the needle barely twitched. Sound like the right method? It's what I interpreted from the diagram in the manual... Should've taken a photo...


Then I measured the connecting rods' small end inner diameter, all 0.707" to 0.709" which is well in spec. And I measured the sideways play on the big end and all were the same at 0.30mm which is also well in spec.


So far so good!


Now time to measure the backlash in the gearbox and that's where I get confused... which set of gears is which... haha.


Left to right in the photo below... 2nd, 5th, 3rd, 4th, 1st.. does that look right? I'm hoping Photobucket displays the photo correctly... it rotated it 180 degrees after I uploaded it. The drive gears should be on the bottom and driven on the top for the correct orientation... I can measure the backlash on these now once I get confirmation of which set it is which.

[pete]

Cleaned up the last four valves last night then checked out the gearbox measurements.

This is how I set up the dial gauge, not ideal with the plate on an angle but it worked:





Backlash measurements in inches...


2nd: 0.001"
5th: 0.002"
3rd: 0.005"
4th: 0.002"
1st: 0.003"


As I suspected third gear is out of spec by 0.002", first is right on the limit. Interestingly enough second is great.


I also measured the gap between the shift fork and the edge of the slot on the gears. 3rd was 0.65mm, 4th and 5th 0.55mm, so all in spec.


However, the width of all the shift forks measured 0.194" which is 0.001" under spec (0.195" minimum thickness).


Then I noticed the teeth on the 3rd and 4th drive gears...








Not pretty! 3rd is far worse and 4th is just starting to show.


So in a perfect world I'd be replacing 3rd and 4th drive/driven gears and all three shift forks. That's roughly $650 from Mick Hone...


Is there any other way to get this sorted? Is it even worth it? I guess if I'm likely to get another 100,000 km's out of the transmission like it is then that's probably ok to leave it as is.


I really want to get the bottom end sorted properly though so I'm a little unsure of how best to proceed right at the moment.

[pete]

Couple of different thoughts on the gearbox over at KA... good second hand gears or brand new gears... but do all the seals/bearings regardless.

Seals/bearings make sense but if I replace two pairs of gears with two brand new pairs of gears, does that make sense if I'm not doing the other three pairs of gears? I'm still very undecided... but thinking if I can get third and fourth pairs with no wear and good backlash, then surely they'll be as good as the remaining 1st, 2nd, and 5th pairs?

And on another note I had the electrician round yesterday finally, so the shed now has power and light and I have better lighting over the work bench in the garage.

[pete]

I learnt my use of the dial gauge was a bit off so I went back and measured 2nd, 5th, and 1st again last night.


This time I set it up like this:





It was a hell of a lot easier to measure, the downside being that I now know every gear is out of spec for backlash. 2nd is 0.006", 5th 0.007", and 1st 0.005". So that puts everything in a different perspective I guess.


I did notice when dismantling the counter shaft that the roller bearing under 1st and the bushings under 2nd and 3rd were really sloppy on the shaft. Looking closely at the teeth they look good, nothing like 3rd and 4th.


How likely is it that it's just the bearing and bushings that are screwed on 1st and 2nd?





Apparently 2nd is pressed onto the drive shaft, any tips on how to get that off? I can't really see if 5th is sloppy on the shaft like 1st and 2nd 'til I can get the drive shaft dismantled.





I really need a better pair of circlip pliers too, the ones I have are horrible and next to useless on those big circlips.


Anyway, I pulled the crankshaft out also last night so I can get set up to measure the runout etc.








The taper's had a bit of a hard life but I'm sure that and the thread will clean up ok and I'm pretty sure someone has mentioned there's a way to lap the rotor onto the taper.








I'll have to set something up tonight I can sit the crankshaft up on so I can take those measurments.


Once that's done, I can measure runout etc. on the valves and hopefully check the valve springs with a weight on them, then I should know where I'm at with the motor and can move on to some repairs on the front cowl and tail piece I think.

[Charlie G]

Gees! Hard life, I guess so!

[pete]

Yup, for sure! All fixable though... at least so far

[SVSooke]

I struggled with that style circlip pliers for years till i got a whole set of different sized one with a case on sale at Princess Auto.Hated doing clips before,now they're way easier most of the time.Sorry to hear of your gearbox woes.

[pete]

Yeah I think that type are the way to go Greg, just a small selection of good strong pliers in various sizes.

Unfortunately it's looking like the gearbox woes are the least of my problems...

I measured the crankshaft runout last night and it measures 0.005", service limit 0.004". And yep I measured twice to be sure...



At least the sideways wear is in spec, all between 0.035 and 0.045" and service limit is 0.12".



Not sure on the crank really... 0.001" doesn't seem like much but the service manual says replace it... and something that heavy at even 6000RPM is potentially going to start wobbling if it gets too much out of line...

[SVSooke]

Hmmmmm...... from every indication that engine was run hard and put away wet

[Nessism]

Great job Pete! I'm enjoying your thread!

Not that it's a democracy, but I vote used transmission parts. Hopefully you can find some for a reasonable price.

Regarding the crank, it can be straightened. I was able to put my 1000S crank back to .001" by a little prudent whacking. It wasn't as far out as your but I'm pretty sure you can fix it.

[pete]

Agreed Greg, someone used her hard... very hard!

And cheers Ed, glad to have you along for the ride

I'm 99% on decided on use bits for the transmission, especially after seeing the state of the bearings/bushes on the counter shaft. I think 99% of the backlash will go away just changing those. Pity about the facing on 3rd/4th though.

As for the crankshaft, there are two people locally who should be able to give me a good solid opinion on how to proceed so I'll hang off on any hammering until either of those two have laid eyes on it

[loud et]

Pete, congrats on getting your Kat! I know in my time here you have always been the biggest drooler of them all.
I know with your passion to have one FINALLY you will make it happen. It was nice to see the pics of you mocking up the parts on the frame.
Once you get this engine sorted out the rest will be cake. Expensive cake....but hey, it's a small investment to enjoy something the rest of your days.
Subscribed....Happy for you.