slow cranking

[dschwandt]

Have you read section 9?

Proper cranking speed less that 600 RPM, is needed to make it work as designed.

ACR operation is a function of the cam and ACR spring.
Are you sure the spring is not missing, broken or not properly in place?
Does the engine still crank slow in a no-compression mode w/the plug removed ?
Proper operation is determined using a dial indicator, indicated on top of the exhaust valve and observed and measured during the compression stroke.
This is an operation that should be part of any ACR equipped engine overhaul.

I'd have that SG checked out by a shop that knows them.

 

[bwstevens]

As Dschwandt asked about cranking with the sparkplug out . Page 3.5 and 3.6 tells how to adjust the valves. You may want to squirt a little oil on the piston top just to add to the cylinder lube.

 

[Joe Williams]

well today I unhook the drive shaft the engine started and ran for a while . As soon as it it died I tried to restart it and turned over real slow . It would not start. I am pretty sure I checked the ring gap but I'm getting old. When the engine warms up would the ring expand enough to not turn over like it should?

 

[mfrade]

"When the engine warms up would the ring expand enough to not turn over like it should?"

Yes. the gap will become smaller, the ends could touch and the ring could tighten against the cylinder. But if that were true, then when cold it would spin over fine.

 

[abthomas]

unless you're absolutely sure everything was assembled correctly during the rebuild,all clearances correct,cam to crank timing marks aligned correctly, rings checked in the bore for end gap, piston skirt to bore clearance , acr working correctly etc.etc. you'll likely end up tearing it back apart to find the problem if it's not a starter issue ! ask me how I know this ! been there done it ! these are pretty simple little engines to rebuild and they'll get easier after the first couple !

 

[Joe Williams]

"When the engine warms up would the ring expand enough to not turn over like it should?"

Yes. the gap will become smaller, the ends could touch and the ring could tighten against the cylinder. But if that were true, then when cold it would spin over fine.

It dosen't turn over find when cold

 

[mfrade]

It dosen't turn over find when cold

With the v-belt loose or disconnected from the starter / generator, does the engine still turn hard? If yes, start disassembling til you find out why it's in a bind! If no, then look into the Starter/Generator....

 

[Joe Williams]

With the v-belt loose or disconnected from the starter / generator, does the engine still turn hard? If yes, start disassembling til you find out why it's in a bind! If no, then look into the Starter/Generator....

Have you read section 9?

Proper cranking speed less that 600 RPM, is needed to make it work as designed.

ACR operation is a function of the cam and ACR spring.
Are you sure the spring is not missing, broken or not properly in place?
Does the engine still crank slow in a no-compression mode w/the plug removed ?
Proper operation is determined using a dial indicator, indicated on top of the exhaust valve and observed and measured during the compression stroke.
This is an operation that should be part of any ACR equipped engine overhaul.

I'd have that SG checked out by a shop that knows them.

with plug removed with starter it sales around like it should. does this mean the compression release is not working?

 

[bwstevens]

Is the engine bound up ? If you have a compression tester. 50 60 pounds it's working 100 or so it's not

 

[Joe Williams]

Is the engine bound up ? If you have a compression tester. 50 60 pounds it's working 100 or so it's not

my compression was about 32

 

[bwstevens]

Have you tried jumping the starter directly with a bigger battery? You may have a bad cable in the mix.

 

[Joe Williams]

my compression was about 32

but it only cranks very little

 

[bwstevens]

I would check out the starter for rubbing armature like worn bearings and make sure that the commutater is clean.

 

[charles germer]

something dumb i did myself on my first K series motor rebuild comes to mind, as you say it started and ran for a short time.

did you properly install the connecting rod? the dipper hole in the big end must face the camshaft, if not zero oil the bearing and they lock up in just a few mins. after that they crank very slow if they crank at all

 

[mfrade]

with plug removed with starter it sales around like it should. does this mean the compression release is not working?

It sure sounds like it. I guess the easiest check would be to remove the cylinder head and by hand rotate the engine and verify that on the compression stroke, the exhaust valve opens.

 

[bwstevens]

A couple of ways to do is to listen to the muffler when you crank it . you can hear my 149 hiss out the muffler on compression. Or pull the lifter cover off an observe the lifters. Joe states that cranking compression is around 30 pounds so I would say that it set close to what is necessary .

 

[Joe Williams]

It looks like the compression release was not working. The spring was off about how far should the valve be open. I don't have a dial indicator.

 

[mfrade]

It looks like the compression release was not working. The spring was off about how far should the valve be open. I don't have a dial indicator.

Quoted David S., K341 ACR Should be set from .031-.042
Refer to section 9 in the FSM for ACR info.

https://resources.kohler.com/power/kohler/enginesUS/pdf/tp_2379.pdf

Do you have feeler gauges? You can "stack" the leafs together and compare the height of the valve top... crude but it's better than just an eyeball. Check with an auto zone parts store ( or any auto supply house) see if they can rent out and indicator setup.. You could also reset /reinstall the spring and just try it. Maybe the adjustment didn't change and the spring just got knocked off when handling the cam during the "rebuild".?.?.?

 

[jkoenig]

Glad you found the problem. Let’s go with Mike’s “knocked off when handling”. PM me if it breaks. I recently found a pair of new springs In my stuff.