KZ305 Rebuild...attempt

wrote:

wrote:

Considering the low mileage on the engine the bores will be fine.  

The head shouldn't take much to clean up either.

A new piston and two new sets of rings and you will be well on your way!

Oh, and tend to the oiling system.  There was a thread here recently where the weakness in the system were discussed so you might want to find that thread and do all you can to fix that.


 

Unless his quote on the head changes my mind I already decided to go as is and just replace the one piston. It saves me $160 for the two bores, $75 on a piston, and saves me from having wasted the $60 on standard rings that I foolishly (or presciently!) already ordered. This $$$ can all go into the kitty for snagging the next cheap KZ440 that comes along needing TLC and I'll have this to ride while I TLC it. And it really wasn't hard tearing it down so if I have to do it again in a few years, no biggy. maybe I'll be richer by then. But the machinist thought it was probably just from running lean, so if I fix that I shouldn't have a repeat any time too soon.

I found this thread that talks about a long bolt blocking a gallery and also mentions the lame strainer mentioned a few posts above. I presume this is the one you referred to. I guess it won't hurt to pull the clutch cover and see if I'm frightened by what I see or not...a little more info on where to find that bolt might be helpful but maybe it will be obvious.

www.kzrider.com/forum/2-engine/614557-kz...blowing-their-cranks


 

Hope I'm understanding correctly and you are going to go through the head.  It shouldn't need any more than cleaning, lapping the valves, and new valve stem seals.

If your machinest says the bores are good I'd take that to the bank.

wrote:

wrote:

wrote:

Considering the low mileage on the engine the bores will be fine.  

The head shouldn't take much to clean up either.

A new piston and two new sets of rings and you will be well on your way!

Oh, and tend to the oiling system.  There was a thread here recently where the weakness in the system were discussed so you might want to find that thread and do all you can to fix that.



 

Unless his quote on the head changes my mind I already decided to go as is and just replace the one piston. It saves me $160 for the two bores, $75 on a piston, and saves me from having wasted the $60 on standard rings that I foolishly (or presciently!) already ordered. This $$$ can all go into the kitty for snagging the next cheap KZ440 that comes along needing TLC and I'll have this to ride while I TLC it. And it really wasn't hard tearing it down so if I have to do it again in a few years, no biggy. maybe I'll be richer by then. But the machinist thought it was probably just from running lean, so if I fix that I shouldn't have a repeat any time too soon.

I found this thread that talks about a long bolt blocking a gallery and also mentions the lame strainer mentioned a few posts above. I presume this is the one you referred to. I guess it won't hurt to pull the clutch cover and see if I'm frightened by what I see or not...a little more info on where to find that bolt might be helpful but maybe it will be obvious.

www.kzrider.com/forum/2-engine/614557-kz...blowing-their-cranks



 

Hope I'm understanding correctly and you are going to go through the head.  It shouldn't need any more than cleaning, lapping the valves, and new valve stem seals.

If your machinest says the bores are good I'd take that to the bank.
 

 I left the head with him and he's going to give me a quote on it when he gets a chance to pull it apart. That definitely needs to get done. He asked me for the bore spec so I presume he's going to measure it and will ask him to if he hasn't. Unless its exceeded 61.1 mm its safe to leave as is. He certainly believed that already and I trust him.

I see multiple aftermarket valve stem seals out there...is there a recommended brand? I'm not keen on trusting 40 year old rubber, if I can even find NOS.  The kit I have has 4 "o ring valve adjust" but those must be for the valve guides, right?
 

wrote:

It's up to you but it's an easy measurement and your machinist will have the tools.  I would never pull the cylinders and not check the bores.  At least you'll know they are OK.


 

Well, I meant I will probably leave the bores alone and just replace 1 piston IF the bore measures ok.  If this starts getting toward $500 or more then heck, I know where I can probably get a 440 for not much more than that...

But I think I'll get by with just a new piston, 2 sets of rings and whatever head work it needs and it should be well under 500. I've got the clutch cover screws soaking so I can go check the strainer and try to find that troublesome bolt.

Checked my strainer just now - not too bad. I didn't see the problem plug that was mentioned in the other thread, so let me know if you find it. 

 

No eBay APP ID and/or Cert ID defined in Kunena configurationGreat! Hopefully I'll be inside by morning. I need to get some new JIS screwdrivers today before I even attempt it because those have never been off in the 11 years I've had it.

In case the head quote comes back at 300 dollars or something, has anyone tried these guys?

Just remember that if it costs you more than $500 for repairs you will have a reliable engine that you know was done correctly.  But if you put that money into another bike you won't know if it's going to be reliable.

wrote:

Just remember that if it costs you more than $500 for repairs you will have a reliable engine that you know was done correctly.  But if you put that money into another bike you won't know if it's going to be reliable.
 

That's a risk of course but parts are easier to find for those. Plus I doubt my troubles or expenses are over with this one either, once the engine is back in. Then its back to messing with the carbs and boots and points and coils and....bahhhh.  I'm hoping this comes in cheap enough that I can have my cake (a 440) and eat/ride it (the 305) too.  But I'll settle for either or as long as I don't spend enough for both on this one.



 

wrote:

wrote:

Just remember that if it costs you more than $500 for repairs you will have a reliable engine that you know was done correctly.  But if you put that money into another bike you won't know if it's going to be reliable.

 

That's a risk of course but parts are easier to find for those. Plus I doubt my troubles or expenses are over with this one either, once the engine is back in. Then its back to messing with the carbs and boots and points and coils and....bahhhh.  I'm hoping this comes in cheap enough that I can have my cake (a 440) and eat/ride it (the 305) too.  But I'll settle for either or as long as I don't spend enough for both on this one.




 

It's going to cost regardless. My project is first ever when I decided not to track expenses. Don't even want to know. Yes, you can get running one, but items you listed - points, coils, etc - most likely will need attention sooner or later.

Ordered my piston. Good grief its not going to be here until May 21-June 9! But it was the only new standard piston I could find.

 

No eBay APP ID and/or Cert ID defined in Kunena configuration

wrote:

Great! Hopefully I'll be inside by morning. I need to get some new JIS screwdrivers today before I even attempt it because those have never been off in the 11 years I've had it.

In case the head quote comes back at 300 dollars or something, has anyone tried these guys?


 

I've used Schumann's. He built a custom titanium valve train for my 750 twin with full race port and polish as well. Good prices and good service. He also let me pepper him with questions for almost an hour. 10/10 would reccommend

I guess 3 days of soaking the clutch cover bolts wasn't enough...got one loose and stripped the next one, not a good batting average so back to the soaking we go. No rush since the piston is still at least 3 weeks out...

Try heat cycles. Also strike the head of the bolt with a brass bar and hammer. Hit it like you’d strike a bell. Quick firm, but not heavy. It will help shock them loose. Do you have an impact driver. Invaluable tool for motorcycle work.