K341 Hard Starting

[uk175horse 17]

I've got a C-175 with an Kohler K341 (dark blue colour, which I believe was a replacement/export version?)

I've had it a few months, and was starting pretty well, but last few starts have needed 4-5 attempts at cranking to get it going. But it runs and idles pretty well once its going, ran fine for 30 mins +

I'm pretty new to the whole engine game, so want to keep this Kohler engine and get it running nicely but trying to figure out what to do first. 

 

I replaced all the fuel line and cleaned out the fuel tank when I first got it, aside from that drained and re-filled the oil, and gave all the fins/exterior a clean. 

I took the spark plug out and its sooty black, as is the muffler. Also checked the points gap, looks like its about 0.016" , but definatley under 0.02" , waiting on feeler gauge with more increments!

 

 

Got a new gasket set, so I'm thinking first thing is to take the head off and inspect the cylinder and valves to get an idea of the condition.

Not sure if its worth replacing anything else yet - maybe the plug?

Worth trying to adjust the carb or points gap? 

 

 

[WHX?? 46,956]

Yes start with the points at 020. Yes definitely adjust the carb and consider a cleaning. 

Sounds like the rest of your plan is a good start. 

[ebinmaine 63,349]

Seconded. .. except I'd just go right ahead and clean the carb. THEN Adjust it. 

 

I'd check the fuel pump condition as well. 

They're not the best at pulling fuel that far while not primed.  

 

 

[Ed Kennell 35,949]

5 minutes ago, ebinmaine said:

I'd check the fuel pump condition as well. 

                           Sounds like a candidate for a primer bulb.

 

[kpinnc 10,915]

2 hours ago, Ed Kennell said:

Sounds like a candidate for a primer bulb.

 

 

Number one issue with a fuel tank under the seat. Makes mine fire on the second revolution. Saves your battery and starter too. 

[SylvanLakeWH 24,243]

x2

 

Work like a charm...

 

 

[953 nut 52,027]

I would begin with the ignition timing, it is set by adjusting the ignition points. The attached manual has information about "Static Timing" that is excelent.

 

 

[uk175horse 17]

OK thanks for the advise so far - so I've already got a primer bulb in place as I saw the idea on another thread and the previous owner said they had to blow into the fuel tank to get it going!

I'm a bit unsure how much I should actually pump it though before I end up flooding the engine?

 

So I got started on taking the engine apart, removed the shroud and cleaned up all the cooling fins first. Then I set points to 0.02" and confirmed that they start to open when the flywheel hits the S timing mark, so hopefully timing is good. 

 

Going to clean up the carb and try and tune after this - I never try and change too many things at once, so I can figure out which thing helped - or broke it!

 

So this is what I found today - but looks very heavy carbon deposits to me, and guessing the oil isn't too good..! Before and after photos after I cleaned it all up. Does it look OK after?

I also measured the cylinder bore using a telescoping gaugue and digital calipers - looks like 3.749" when measured at 3 different points, so I guess its not too worn?

 

 

 

[ebinmaine 63,349]

11 hours ago, uk175horse said:

Does it look OK after?

Looks good from my house. 

 

I don't have bore gauges so we "measure"  by  the @Pullstart  "eyecrometer" 

Being an old kohler iron engine it'll be very forgiving. 

As long as the piston looks fairly tight in the bore we'll run em.  

 

 

[Pullstart 59,920]

If I haven’t already,   It looks like you’re on the right track to getting a good runner!  Do you have a large enough flat surface to give that head a good hone?  Many people use thick glass and a sheet of sandpaper, I have a machined aluminum plate that works well.  

[953 nut 52,027]

3 hours ago, ebinmaine said:

"eyecrometer"

Gotta call BS on that word,    looked it up and it ain't there!                                     But I like it.          

[ebinmaine 63,349]

44 minutes ago, 953 nut said:

Gotta call BS on that word,    looked it up and it ain't there!                             

 

Credit to Kevin as I stated above.  

 

Maybe he's a trend setter and verbiage inventor?

 

 

[Pullstart 59,920]

1 hour ago, ebinmaine said:

 

Credit to Kevin as I stated above.  

 

Maybe he's a trend setter and verbiage inventor?

 

 

Not sure where I first heard eyecrometer, but it should be a true word.
 

An accurate measurement, based on one’s past experience.

 

It looks close-e-nuff by my eyecrometer.

My eyecrometer says that is 3/16” thick.

My eyecrometer says we need to grind more.

[squonk 39,040]

I got a shelf with some broken Kohler pistons and rods that say the eyecrometer only counts in hand grenades and horse shoes.

 

Look at this cyl wall. Doesn't look horrible.

 

 

This is the piston that was rattling around in it.

 

 

Edited March 3 by squonk

[uk175horse 17]

Wow that piston above is shocking , was it running like that?

Right so I followed the suggestion to flatten the head, I've got a planer table which hopefully is very flat and some 400grip sand paper. New head gasket and re Torqued all the bolts.

Never cleaned a carb before so will have to check that out.

Got a bit carried away and opened up valve cover and check clearance. They are low, like 0.06 on intake, any reason the clearance should differ, like if P.O adjusted due to wear or something?

Hopefully this engine has another few decades in it

[squonk 39,040]

1 minute ago, uk175horse said:

Wow that piston above is shocking , was it running like that?

Right so I followed the suggestion to flatten the head, I've got a planer table which hopefully is very flat and some 400grip sand paper. New head gasket and re Torqued all the bolts.

Never cleaned a carb before so will have to check that out.

Got a bit carried away and opened up valve cover and check clearance. They are low, like 0.06 on intake, any reason the clearance should differ, like if P.O adjusted due to wear or something?

Hopefully this engine has another few decades in it

Yes that piston was still in a running engine. 

 

Valve clearance will change over time. As the valve face and seat wear, the gap will close up.

[uk175horse 17]

14 hours ago, squonk said:

Yes that piston was still in a running engine. 

 

Valve clearance will change over time. As the valve face and seat wear, the gap will close up.

Now I'm confused so is it best to set valve clearance to with the spec ? Or is it adjusted right now as the valves are worn and the P.O was right ! They are a pain to get at so want to get it right while I can get to it

[ebinmaine 63,349]

4 hours ago, uk175horse said:

Now I'm confused so is it best to set valve clearance to with the spec ? Or is it adjusted right now as the valves are worn and the P.O was right ! They are a pain to get at so want to get it right while I can get to it

 

I'd adjust them both to the smallest tolerance at least. 

 

19 hours ago, uk175horse said:

Never cleaned a carb before so will have to check that out.

 

The Kohler carbs are about as simple as one can get. 

 

I've rebuilt more than a few.  

 

I do NOT advise trying to remove either the Welch plug or the main jet in the middle of the center pickup tube. 

 

Get a Kohler brand rebuild kit if possible. 

 

Clean it. A lot. Then clean it again. 

 

 

[squonk 39,040]

5 hours ago, uk175horse said:

Now I'm confused so is it best to set valve clearance to with the spec ? Or is it adjusted right now as the valves are worn and the P.O was right ! They are a pain to get at so want to get it right while I can get to it

It's possible the P.O. never touched the valve adjustment. The intake spec is .008-.010" Lets say it left the factory at .008". In all the years of running the valve seat and face pounded on each other removing a total of .002" of material. That will lower the valve in the block placing the stem closer to the tappet by .002" giving you the .006" clearance your are measuring. Since the head is off I would pull the valves and I would check the valves especially the exhaust. If they are leaking some that will cause hard starting too. It's probably time for a valve job any way. You can take the valves to a machine shop to get the faces ground and resurface the seats on the CHEEP by this method: 

 

 

Edited March 5 by squonk

[uk175horse 17]

So turns out my clearance measuring was off ! Triple checked and intake was 0.010 (spec is 0.008-0.010) so set it the middle to 0.09 and exhaust is already at 0.018..

I wanted to get it running for a job so didn't get around to valve job yet, so put the head back on with new gasket.

And.. typical the part I didn't touch failed , fuel pouring out fuel pump ! 

Got a new Chinese fuel pump but kept original to rebuild if worth it, replacement feels a bit of a poor product just looking at it... 

I gave the carb a good clean too. 

Going to fit the fuel pump and tweak the carb and will report back on the starting . 

But this is the way you learn !

[kpinnc 10,915]

5 hours ago, uk175horse said:

I gave the carb a good clean too. 

Going to fit the fuel pump and tweak the carb and will report back on the starting . 

But this is the way you learn !

 

Those butterfly screws look awfully shiny. Are they steel? Best to use brass screws in case one comes loose and is injested. Brass will crush down and likely won't damage anything. Steels screws will bust the head or piston. 

 

Brass screws and red loctite are far less likely to break anything...

[ebinmaine 63,349]

8 hours ago, uk175horse said:

Got a new Chinese fuel pump but kept original to rebuild if worth it, replacement feels a bit of a poor product just looking at it... 

I gave the carb a good clean too.

 

After having several go bad I no longer advice using a cheap carb. 

Toss it on your desk as a paperweight and clean the original. 

It's very easy to properly rebuild an older Kohler. I'd be happy to share good written instructions if I can find them. 

 

The most important part is to check the throttle shaft to bore wear.  

 

3 hours ago, kpinnc said:

butterfly screws

 

All the new cheapees I've seen ... and many of the older originals have steel screws. 

[uk175horse 17]

Not sure if it was clear but I'm definitely  keeping the original carb , walbro adjustable model. Will see if I can source any brass screws too.

So the good news is after replacing fuel pump with aftermarket manual one (and all I did before that!) the starting is much better , now it starts first time !

The bad news is that I think I messed up replacing the head gasket,  I could see a bit of white smoke coming out around the head near the exhaust and the top cooling fin looks a bit oily.

I checked the torque after and it was lower , so I retorqued again to spec , hoping that does it, or is it too late once a leak happens ? 

Can I take it off and add some gasket maker and refit ? Or are we talking another gasket and replace ? 

 

[953 nut 52,027]

11 hours ago, uk175horse said:

I retorqued again to spec , hoping that does it, or is it too late once a leak happens ? 

Can I take it off and add some gasket maker and refit ? Or are we talking another gasket and replace ?

Glad it is starting well. Retorquing is something the service manual says must be done. That should eliminate the problem, if nor a new gasket will be needed.

[Sailman 1,134]

On 3/14/2024 at 4:51 AM, ebinmaine said:

It's very easy to properly rebuild an older Kohler. I'd be happy to share good written instructions if I can find them.

 Don't mean to hijack the thread but I could use the instructions too @ebinmaine. Have a carb for my K 161 that I cleaned and rebuilt but doesn't seem to want to start the engine. Might be "the shaft to bore wear"?