Backfire problem

[Chrishar 679]

Have a kohler k161 that on my 753 when I crank the motor all it wants to do is backfire throw the carburetor it will not even try to start I tried drift points and condenser and coil but no luck the motor was running good when I took it off the tractor all I did was reseal the gaskets and replace the governor cross shaft the camshaft was a two piece can I have got the two pieces out of time for the points the cam and crank gears are in time I check that need help 

[Pullstart 66,653]

It’s challenging to read your details, but am I understanding the cam was removed as well or did the cam not come out?  
 

7 hours ago, Chrishar said:

replace the governor cross shaft the camshaft was a two piece can I have got the two pieces out of time for the points the cam and crank gears are in time I check that need help 

 

[Chrishar 679]

I removed the cam it's a two piece I read last night that there is to line's to line up on the two piece cam that's what my unstanding about it 

[Gasaholic 286]

Dot on the stub piece lined up with dot on cam gear, and the stub piece properly indexed into theActuator? Only thing having them 180 degrees outta sync would be to fire points at TDC of exhaust stroke, so that could be causing your backfire. (The points flat is on that stub piece, so putting it in wrong throws your point operation 180 degrees out of sync)

 

Be sure it actually IS a 2-piece camshaft, as I have seen some 1-piece camshafts that actually were broken (between the cam lobes where fuel pump actuator bump is at - They can be broken by a grenading con rod, or by forcing fuel pump actuator to wrong side of cam lobe)  

 

When installing the 2-piece cam, it is helpful to have a temporary alignment pine (slightly smaller than the cam pin) to hold things in place and lined up during installation, and then as you push in the cam pin, the alignment pin slides out. (they were a PITA to get the end play shims in place on too!) 

 

Edited to remove "ACR" - I was thinking compression release, but meant the Automatic Spark Advance actuator (Similar to ACR, but was not for compression release, it was for spark advance timing, which was also meant to ease starting)

Edited August 7, 2023 by Gasaholic
Adding pic of Actuator timing

[Chrishar 679]

That's what my cam look like I didn't know that you had to line dot up that's probably my problem I hope I will take it apart tonight and let you know thanks again for the help 

[Chrishar 679]

This what my cam look like it was 180 out 

[ineedanother 1,668]

8 minutes ago, Chrishar said:

This what my cam look like it was 180 out 

Glad to see you likely resolved the issue and nice to have @Gasaholic aboard 

[squonk 43,736]

That will do it. I went through the same thing last year. Bought a " rebuilt engine" that wouldn't run. Popped through the carb . Replaced the cam with a compression release design.

[Chrishar 679]

Now I have to read to see how to set the points with this cam I never set one with automatic spark advance camshaft before  

[Gasaholic 286]

35 minutes ago, Chrishar said:

Now I have to read to see how to set the points with this cam I never set one with automatic spark advance camshaft before  

Same as all of them - Set points .020 nominal

- If you had a timing light (Or a good seat-of-the-pants sense/feel for it) the ignition timing can be adjusted more precisely, but a .020 point gap generally gets timing right in around that 20-25 degrees or so sweet spot.

 

Timing advance mechanism will bump that a bit closer to 10-15 or thereabouts (I never bothered looking up exact figures) for easier starting...   The few times I did a performance enhancement tweak (Setting points with engine running) I just did it by the seat of the pants til it "felt right"   - same way we often did field repairs on the Farmall at the farm. Timing could also be set using a dwell meter...  But generally .020 point gap does the job.