Register free!
Search
 
     

The Green Industry's Resource Center


Click for Weather
Reply
 
Thread Tools Display Modes
  #1  
Old 05-03-2011, 07:21 PM
KenM KenM is offline
LawnSite Member
 
Join Date: Sep 2010
Location: Rochester NY
Posts: 18
Kohler CV-22 crankshaft gear position

Having a problem with a Kohler CV-22 - see my earlier thread dated 4/29 on this forum - and am wondering if the gear on the crankshaft might have shifted when I threw a rod (it wasn't pretty). It appears that that gear is not keyed to the crank, but is probably just pressed on. If that gear has shifted a bit, it obviously will throw off the valve timing, maybe accounting for my loss of compression as the lifters pump up. So the question is: anybody know what the correct position is for that gear, relative to the keyway at the other end of the shaft (or any other reference)? Thanks!
Reply With Quote
  #2  
Old 05-03-2011, 09:17 PM
Restrorob's Avatar
Restrorob Restrorob is offline
LawnSite Fanatic
 
Join Date: Apr 2005
Location: Show'n my truck off !
Posts: 10,565
I haven't seen nor heard of gear slippage issues, But I'm not saying it couldn't happen.

This is the best I can do in relation to crank/valve timing;





That will be the pto end keyway they're speaking of.....
__________________
Quote:
Originally Posted by piston slapper View Post
You never learn anything until you admit you don't know it all...

"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!
Reply With Quote
  #3  
Old 05-04-2011, 09:36 AM
piston slapper's Avatar
piston slapper piston slapper is offline
LawnSite Platinum Member
 
Join Date: Mar 2010
Location: Tampa Fl
Posts: 4,008
The crankgear is a zero fit ( The gear is heated and installed on the crank)
The gear is in the right position when the timing dot is lined up with the line cast into the counter weight. The line will be about the width of a tooth on the gear and have a ground finish.

They dont usually slip..they crack and break.
Reply With Quote
  #4  
Old 05-04-2011, 11:26 AM
piston slapper's Avatar
piston slapper piston slapper is offline
LawnSite Platinum Member
 
Join Date: Mar 2010
Location: Tampa Fl
Posts: 4,008
Quote:
Originally Posted by piston slapper View Post
The crankgear is a zero fit ( The gear is heated and installed on the crank)
The gear is in the right position when the timing dot is lined up with the line cast into the counter weight. The line will be about the width of a tooth on the gear and have a ground finish.

They dont usually slip..they crack and break.
This picture should help
Attached Images
   
Reply With Quote
  #5  
Old 05-04-2011, 02:27 PM
Sharpcut 1's Avatar
Sharpcut 1 Sharpcut 1 is offline
LawnSite Senior Member
 
Join Date: Sep 2006
Location: Roseville, MI
Posts: 450
I agree with Piston slapper on the dot. Pretty much lined up with the casting mark.

I must dis-agree on the slippage issue. Have had 3 do it in the last couple of years, 2 verticles, and one horizontal. Exmark, Dixie chopper, and Bobcat. The chopper just happened 3 weeks ago. Crank was over $200.00
Reply With Quote
  #6  
Old 05-04-2011, 02:31 PM
Sharpcut 1's Avatar
Sharpcut 1 Sharpcut 1 is offline
LawnSite Senior Member
 
Join Date: Sep 2006
Location: Roseville, MI
Posts: 450
Not trying to make you spend money, but replace the cam if you replace the crank. Only reason I say this, just like a ring and pinion, they wear in together. Replace the crank without the cam, you'll be pulling it apart in a couple of weeks.

Ask me how I know
Reply With Quote
  #7  
Old 05-04-2011, 02:57 PM
piston slapper's Avatar
piston slapper piston slapper is offline
LawnSite Platinum Member
 
Join Date: Mar 2010
Location: Tampa Fl
Posts: 4,008
Quote:
Originally Posted by Sharpcut 1 View Post
Not trying to make you spend money, but replace the cam if you replace the crank. Only reason I say this, just like a ring and pinion, they wear in together. Replace the crank without the cam, you'll be pulling it apart in a couple of weeks.

Ask me how I know
OK....somrbody's gonna ask sooner or later....
HOW DO YOU KNOW?
Reply With Quote
  #8  
Old 05-04-2011, 06:59 PM
KenM KenM is offline
LawnSite Member
 
Join Date: Sep 2010
Location: Rochester NY
Posts: 18
Thanks for all the replies! I pulled this engine from the mower a few hours ago to see where my crank gear dot is, relative to the casting midpoint. It's right where it should be. Maybe I should be happy since I'm not looking at a new crank and cam. But, something is interfering with compression during the starting process and all I can think of is that the lifters are pumping up and not relaxing fast enough, allowing one or more valves to not close on time. So, cam/valve timing is not the culprit. I'm gonna yank the heads apart and measure the new valve lengths vs the old valve lengths (not likely to be the problem, but may as well rule it out); also gonna evaluate the valve springs vs those from a sister engine. Do they weaken after 1700 hours? I'm getting close to just shimming the rockers up as piston slapper previously suggested, but I'd sure like to understand what's going on. Thanks again for all your help to this point. Any other ideas?
Reply With Quote
  #9  
Old 05-04-2011, 10:25 PM
Restrorob's Avatar
Restrorob Restrorob is offline
LawnSite Fanatic
 
Join Date: Apr 2005
Location: Show'n my truck off !
Posts: 10,565
I just read your other thread, Did you ream the valve guides to proper oil clearance for the .25 oversized valves ?

You can't go by feel, They must have 0.056mm or 0.0022in clearance for proper oiling so they won't bind in the guide.

The valves may have "felt" good until you added the tension of the spring, Then add the rocker arm not pushing the valve open dead center and square could cause valve/guide binding.....

What I'm getting at is the engine ran until it blew, The only thing that changed was the oversized valves so that's where I'd be looking.
__________________
Quote:
Originally Posted by piston slapper View Post
You never learn anything until you admit you don't know it all...

"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!

Last edited by Restrorob; 05-04-2011 at 10:29 PM.
Reply With Quote
  #10  
Old 05-05-2011, 09:17 AM
piston slapper's Avatar
piston slapper piston slapper is offline
LawnSite Platinum Member
 
Join Date: Mar 2010
Location: Tampa Fl
Posts: 4,008
Quote:
Originally Posted by Restrorob View Post
I just read your other thread, Did you ream the valve guides to proper oil clearance for the .25 oversized valves ?

You can't go by feel, They must have 0.056mm or 0.0022in clearance for proper oiling so they won't bind in the guide.

The valves may have "felt" good until you added the tension of the spring, Then add the rocker arm not pushing the valve open dead center and square could cause valve/guide binding.....

What I'm getting at is the engine ran until it blew, The only thing that changed was the oversized valves so that's where I'd be looking.
DITTO....DITTO....DITTO...etc.....

KenM ...you created your own problem....It aint the valve springs.

Sharpcut1....still waiting for you to learn me up about cranks and cams....

RestroRob...Are we speaking a foreign language ? This aint rocket science...
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump





Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ©1998 - 2012, LawnSite.comô - Moose River Media
All times are GMT -4. The time now is 04:18 AM.

Page generated in 0.08382 seconds with 8 queries