Need K181 Help ...

[KyBlue 652]

The Kohler on my B80 has been acting up... it still starts like it's supposed to, and runs strong, but It has this really annoying knock ...  Now I know what you're gonna say ... I thought that too. Rod Knock... BUT this knock comes ... and goes?

 

One time I'll start it, and it'll be there, the next two or three times, It won't.  For example, Today I started it move it outside of the shop, and it was there. Last night, I used it to pull my neighbors toro ZTR up from their front yard (it was a DOA machine) and it had no odd noises. Even mowed with it for awhile. Multiple starts/Stops ... No knock.

 

 

WHAT IN THE HECK is going on here ... I know it's gotta be something simple?? Give me a place to start.  I've already contacted a Machine Shop and have it scheduled for a rebuild over December/January ... but I'd like to know what in the world is going on so I can finish out the mowing season hopefully ... 

 

Thanks for the help ...

 

Btw has decent compression, no knock spinning it over w/ no fire.

[Geno 1,928]

What's the point condition and gap?  That can cause a knock sound.

[KyBlue 652]

Right but it wouldn't come/go  .... would it?

[slammer302 2,154]

I would say its the points too

[KyBlue 652]

I'll pull the cover and check tomorrow when I get home from work.  Let ya know what I find. 

 

 Will get a video while I'm at it.

[boovuc 1,090]

Pitted points, gap off.

My K181 did the same thing. 

[KyBlue 652]

Not sure why all of the sudden it would start. Then stop. Then start with it being the points. However I will check them tonight. gotta start somewhere

[Geno 1,928]

Points can do some weird things.    

[KyBlue 652]

So I came home, and first thing, even before coming into the house, I went and pulled the points cover ... Spun the motor over to open the points and The gap was big ... really big ... between 1 and 2 mm ... So I pulled the gap down and fired it off ... No knock ...   Now I don't know if that actually fixed it, or if it just ... didn't do it this time. The Points are pretty worn so I'm gonna buy a set when I get the rest of the parts for the other motor. The sad thing is I have a set already somewhere in the shop (bought 6-7 years ago) ... I gotta get organized!

 

 

Will keep ya'll updated if the knock stays gone, or comes back. :thanks:

[Geno 1,928]

Hopefully it will be gone for good.  See, you can do it we can help!     

 

 

We do get paid for this don't we?  

[KyBlue 652]

Yeah you get paid Geno ... I'm printing you a brand new 25.00 bill with a Kohler engine on it for the portrait. hehe

 

 

It took a little bit to get the gap closer (no feeler gauge atm) but I got it close. I honestly Don't know how it was running as wide as it was gapped ... Does go some way to explain the hard starting when Hot (think its boiling the fuel in the carb too though)

 

Pictures & Video ... If I ever get it uploaded!!!

 

Idling ... waiting patiently

 

 

What she's mowed (this is only part of the front yard)

 

[KyBlue 652]

Just a update for ya... Mowed the yard with it on two different days with random starts here and there... Has stayed gone. Need to close the gap a tad more to maybe fix/help a hard to start when hot condition.

Thank you again everybody!

[KyBlue 652]

Went out this morning and fired her up and ..... it's back.

 

 

Uploading video now.  Point gap is still fine, didn't move ... Pulled the PTO off to make sure there wasn't anything rubbing.  the knock was there through the RPM range. After a second or two @ Wide Open it stopped, and stayed gone as it was returned to Idle.

 

 

http://youtu.be/sW9I19AcURE

 

What in the world is going on here?  I'm baffled lol

Edited September 27, 2014 by 4StarCstms

[Geno 1,928]

Doesn't sound like an internal knock to me but it's hard to tell in the video.  Is the starter bendix disengaging?   

[KyBlue 652]

Yep.  Start is just ... tired.  And the bendix is half chewed ... 

 

 

When I get the extra, I'll bring it down and we'll check it out if it's still giving me problems ... but I agree, I don't think that it's internal... It's something else.

[Geno 1,928]

Yeah you get paid Geno ...

 

[cjsdad 18]

The points gap is how you set the timing.  If the cam lobe that operates the pushrod for the points is worn down it would cause irratic timing.  If the timing advances too much you get detonation which sounds like a rod knock.  The factory pushrod is a lightweight metal rod that can be pulled out once the points are removed.  Something you can do to find out if the cam is worn without taking the pan off is to take the points off and try wiggling the pushrod as you turn the engine over.  If it gets longer and shorter as you wiggle the pushrod the cam lobe is worn down. 

 

Once the cam lobe is worn there are two options.  Replace the camshaft, or replace the pushrod with one that has a wider head on it.  Here is my worn cam and the pushrod I made for mine.  An option to replacing the pushrod is to thread one end and screw a nut on it.

 

 

[Terry M-(Moderator) 2,125]

Watched the video and watched how well that K181 turns that tiller in the dirt...  Some guys here have been telling me that an 8 hp is too small to operate a rearmount tiller.   I see now thats not true....guess I might be keeping m eyes out someday for a rear mount tiller. we'll see