timing?

[scratchawl 0]

rebuilt a k181 8hp to put on a 633.  bought a gasket kit with new piston off ebay and installed. The engine spit gas back out the carb and had a distinct knock.  took it back down and the oil tail piece had broken off and was rattleing around. reinstalled the old connecting rod and started it up.  still spits a little gas back out the carb.  is the timing off maybe a tooth or two?  is it worth tearing back down and changing?  is there a way to check timing without taking it all apart?

 

[stevasaurus 22,229]

Actually, the points control the timing in these old Kohlers.  The points should be set at .020".  Sometimes they will run better at .018"  You can also use the "static" method...do a search on this site for that...it's done with a multi-meter. 

Edited November 30, 2013 by stevasaurus

[Terry M-(Moderator) 2,125]

Actually, the points control the timing in these old Kohlers.  The points should be set at .020".  Sometimes they will run better at .018"  You can also use the "static" method...do a search on this site for that...it's dome with a multi-meter. 

Steve, with knocking and fuel spitting out the carburetor, do you think that the cam could be off a tooth or so???.....and what would make the oil dipper break off?

[squonk 38,848]

Those rod tail pieces break all the time. The get tiny fractures in the metal and let go whenever they feel like it. I had a K341 apart last year and sent the pieces over to a Kart Racing buddy of mine to check them. He uses a special dye on aluminum and that rod dipper looked like a spider built a nest on it with all the hairline cracks that showed up.

[stevasaurus 22,229]

Very possible Terry, but the points are the 1st thing to look at...valve clearance might be the 2nd thing to check...and then tear it back down...just being that logical guy.  Is it possible to be 180 degrees off on these small engines...I have not torn one of these apart yet.  I kind of rely on my experience with tearing down car engines from some years ago.  I need to tear one down. 

Edited November 29, 2013 by stevasaurus

[Terry M-(Moderator) 2,125]

Those rod tail pieces break all the time. The get tiny fractures in the metal and let go whenever they feel like it. I had a K341 apart last year and sent the pieces over to a Kart Racing buddy of mine to check them. He uses a special dye on aluminum and that rod dipper looked like a spider built a nest on it with all the hairline cracks that showed up.

Well thats not good and I know very little about kohlers  ...but I guess it can happen.

[squonk 38,848]

Very possible Terry, but the points are the 1st thing to look at...valve clearance might be the 2nd thing to check...and then tear it back down...just being that logical guy.  Is it possible to be 180 degrees off on these small engines...I have not torn one of these apart yet.  I kind of rely on my experience with tearing down car engines from some years ago.  I need to tear one down. 

How about a special video:  "Tearing down a Kohler From the Shores of Lake Michigan"!     

[Terry M-(Moderator) 2,125]

Very possible Terry, but the points are the 1st thing to look at...valve clearance might be the 2nd thing to check...and then tear it back down...just being that logical guy.  Is it possible to be 180 degrees off on these small engines...I have not torn one of these apart yet.  I kind of rely on my experience with tearing down car engines from some years ago.  I need to tear one down. 

Just thinking out loud steve  Im very much interested in this problem...symptoms sound Identical to my problem HH60 tecumseh. (quiet Squonk)

[sorekiwi 761]

A quick check of valve timing could be to remove the valve cover and watch the valves rocking - midway between the exhaust valve closing and the inlet valve opening should be TDC.,  I'm not sure that doing it this way will be accurate enough to see if you are one tooth off or not.

 

While you are in there, check the valve clearance as well, a tight inlet valve could provide the same symptom.

[953 nut 51,541]

   Sorry to hear of your problems. That oil splash thingie on most kits is long enough to use in deep sump oil pans and I have had to cut it down in the past. The spitting back could be cam timing, but I would think the compressin would be very low. Since it runs the compression has to be rather good, I would take a look at the carb. and the engine breather first. If the float is set too high or the vent hole is plugged it could cause spitting.

 

 As I recall (I'm suffering from oldtimers, can't remember all the time) the cam gear has one tooth with a dot on the side and the crank has two teeth with dots on them, the cam tooth with the dot goes between the two dots.

 

Good luck and keep us posted.

 

 

Edited November 30, 2013 by 953 nut

[cjsdad 18]

For the camshaft timing it is very easy to get it a tooth off.  The cam and crank gears slide together as you insert the crankshaft and since they are hypoid gears they have to be slightly rotated together. The picture below shows the camshaft marking.  I don't seem to have a pic of the crank mark but it is cast into the crank gear.  More like a lump in the crank casting that kinda resembles an arrow.  You can see both marks with the oil pan off. 

 

If the cam is 180 degrees out the camshaft eccentric for the points won't be in the right place.    Seriously though, it would be impossible to get the cam 180 out on a 1 cylinder engine.  Either way the piston is at TDC.  If it is a tooth or two off though it needs to be corrected or it will never run right.

 

The points timing needs to be set correctly after taking the engine apart too.  The ignition timing is set by the dwell of the points.  There is a peek hole in the shroud over the flywheel where you can find the TDC marking on it and another mark for the correct timing advance.  If you are familiar with automotive engines you can set the points from there.  It is like setting the dwell on a Chevy distributor, you move the points in and out and that adjusts the timing. 

 

 

Edited November 30, 2013 by cjsdad

[TT-(Moderator) 1,127]

Here's a pic of both marks on a 161:

@scratchawl: did you remove the camshaft & followers (lifters) during your "rebuild"?

 

I'm with Kiwi Mike on the spitting possibly being caused by a "tight" intake valve.

[WH nut 553]

How far did you tear it down. Did you just put a rod and piston in it because the rod was broke. If that's the case I would look at the cam very close. When the rod breaks it likes to smack the cam and could have cracked it, or even broke it and threw the timing off.Give us a little history of why you tore it down and how it ran before.

[Coadster32 793]

Not sure if this applies, but I'm pretty sure the oil dipper is directional (rod directional). When in the higher rpm range, it matters the most. Is it backfiring, and did the knock go away with the old rod after the new one was borke? If the gas is just dribbling out, it could be a float/valve problem. If you have an inline shutoff valve on the gas supply, you might try shutting it about 1/2 way, and just try to idle the engine. Just a thought.

[scratchawl 0]

ok heres what happene d. father in law, who rebuilt the engine, took it all the way down,  took it back apart and reset the crank and timing marks reinstalled all the guts. started to put the bearing plate on as he was tightening the bolts down he heard a crack started to tighten the next and heard another crack removed the bearing plate and the block was in three pieces.  now the question is can he take the electric start off the 8hp k181 and put it on the 6hp k141?

[TT-(Moderator) 1,127]

If the block is drilled & tapped for the starter mounting bolts, electric start can be added.

 

I'm not sure I'd let your father in law do it though.

[scratchawl 0]

he has more patience then me have no hard feelings he put a lot of work into the rebuild.  will the flywheel off the 6hp fit up to the

8hp

[TT-(Moderator) 1,127]

he has more patience then me have no hard feelings he put a lot of work into the rebuild.  will the flywheel off the 6hp fit up to the

8hp

Just funnin' at ya on the father in law part.

 

As far as the flywheel goes............

Although most of the external parts on the K141/161/181 engines look similar and often interchange, there are enough variations to prohibit answering that question accurately.

I would have to (at least) see some pictures of what you're working with - and you never actually specified which type of electric start you're using or the approximate age of the 181.

[scratchawl 0]

i'll try to get some pixs tomorrow