Hard starts and impossible restart

[RetroMower 349]

Previously I mentioned how well my recently resurrected C100 and K241 went which is true when its running it does very well but it takes some very specific fiddling to start and restarts require ear plugs thanks to the backfires. Smells like its running rich and it smokes a little white. Im pretty sure the head gasket leaks as well. So is more carb tuning all I need or would a complete engine rebuild be in order? 

[ebinmaine 72,671]

My first gut instinct on that would be to pop the head off and sand it on a piece of glass or flat metal and then reinstall and maybe do a leak down test?

 

Have you rebuilt the carb? Or replaced the fuel lines or anything like that? Forget my bad memory if you've already stated this stuff.

[RetroMower 349]

2 hours ago, ebinmaine said:

My first gut instinct on that would be to pop the head off and sand it on a piece of glass or flat metal and then reinstall and maybe do a leak down test?

 

Have you rebuilt the carb? Or replaced the fuel lines or anything like that? Forget my bad memory if you've already stated this stuff.

As far as the carb is concerned, to get it to this point I removed it, disassembled it, soaked all metal components in acetone with gaskets removed, cleaned main jet, tiny ports, and mixture needle and seats as best i could, reassembled and adj mixture screws according to a kohler engine manual someone here provided me with. It always seems rich no matter what i do. Cleaned plug comes out fuzzy black and a bit wet after 5 min running. I shouldn't have said impossible restarts because i can get it running when hot but a lot of backfires have to be endured in doing so 

 

And yes every external component has been changed. Coil, condenser, plug and plug wire, fuel lines and in line filter. (Tank lacks screen). Battery cables and new wires to ponts and coil 

Edited April 16, 2019 by RetroMower
Forgot some details srry

[gwest_ca-(File Mod) 11,482]

Try the original condenser on it. They can cause symptoms one would swear are fuel related.

You do have the condenser connected to the (-) side of the coil?

 

Garry  

[oliver2-44 10,715]

I agree with Quest,  try the original condenser.  

Also, have you checked the carb for air leaks?  Spray some carb cleaner around the throttle shaft and base of carb to block area.  if the engine increases speed you have an air leak.  

[RetroMower 349]

2 hours ago, gwest_ca said:

Try the original condenser on it. They can cause symptoms one would swear are fuel related.

You do have the condenser connected to the (-) side of the coil?

 

Garry  

I do indeed have it on the (-) side of the coil. But i will try the old one. Ill let you know how it goes.

 

Also ebinmaine suggested cleaning and surfacing the head. Id love to so Wheres the best place for a head gasket? And how is a leakdown test done on an engine equipped with compression release?

 

 

Edited April 17, 2019 by RetroMower

[roadapples 6,983]

I've seen head gaskets on ebay for about $12...

[pacer 3,177]

Backfiring does indeed sound like an ignition issue, and I agree the condenser can give these problems and is a quick and easy change.

 

I recently had an Onan eating my lunch with several problems that mostly seemed carburetor related -- but after peeling the paint off the walls with my vocabulary, I finally noticed a very small crack in the insulation wire on the condenser and it was very close to a mounting bolt head. Put another condenser on and --- whoa! that was the problem. Apparently the wire being so close to the bolt head and it being hot from engine heat, the wire became brittle and caused the crack, therefore letting the magic electrons escape.

[Daddy Don 909]

I was having the same problem with my C125 changed the plug and points. Set the points on .19 and now it starts and runs like a new motor. The point that I took off looked good but that was the problem. I was causing the plug to foul out. It was plum black with I took it out. I thought it was a fuel problem but it was not. It was the points.   

[RetroMower 349]

7 hours ago, Daddy Don said:

I was having the same problem with my C125 changed the plug and points. Set the points on .19 and now it starts and runs like a new motor. The point that I took off looked good but that was the problem. I was causing the plug to foul out. It was plum black with I took it out. I thought it was a fuel problem but it was not. It was the points.   

The points are one piece i haven't changed because nobody has them on the shelf. I suppose I'll have to dive into the interwebs for a set o points and a head gasket. Thanks for the reply 

[RetroMower 349]

10 hours ago, roadapples said:

I've seen head gaskets on ebay for about $12...

I find it amazing so many of these parts are still available. Fuel pumps, carburetor assemblies, and gasket sets to name a few. Theres stuff i bought at Lowes and Home depot that has been discontinued after one year. Yeah the manufacturing moved overseas but its pretty good for 40-50 machines.

[ebinmaine 72,671]

I haven't had a lot of experience with points one way or the other, good or bad, but there are a lot of people that have a great cleaning preference towards the older points.

It may be in your best interest to get a proper points file and try to clean and reset your own, first.

 

[wallfish 18,091]

3 minutes ago, ebinmaine said:

I haven't had a lot of experience with points one way or the other, good or bad, but there are a lot of people that have a great cleaning preference towards the older points.

It may be in your best interest to get a proper points file and try to clean and reset your own, first.

 

I have 3 brand new sets of points sitting in packages for over 8 years and been through many engines over that time. Originally had 4 packages and changed one set of points because the contacts were pitted so bad. Think most people find the new set of points work because it forces them to be set properly because of the swap. Just my opinion and luck with them so far.

 

 

[pfrederi 18,670]

Leak Down Tests are the same with or with out ACR.  it is a compression test that doesn't work well with ACR

[Mike'sHorseBarn 3,248]

I'd try points and condenser first before I worried about planing the head unless you know for a fact it is leaking. I've used a lot of points and condensers from isavetractors.com and have never had a problem with them. 

 

https://isavetractors.com/points-and-condenser-set-for-kohler-k-series/

[RetroMower 349]

4 hours ago, Mike'sHorseBarn said:

I'd try points and condenser first before I worried about planing the head unless you know for a fact it is leaking. I've used a lot of points and condensers from isavetractors.com and have never had a problem with them. 

 

https://isavetractors.com/points-and-condenser-set-for-kohler-k-series/

I think I do have a leaky head gasket because of some black on the bottom cooling fins. I know its not my #1 problem but removing the head will tell me a lot more of this motors condition.  As for Isavetractors i believe that place will be hearing from me soon. But on another note i did swap out the brand new condenser for the original one and it backfired like a machine gun so i used the one off the b100. Runs ok but no better than before. I did notice someting odd on the new condenser I removed. What is the problem here?

[gwest_ca-(File Mod) 11,482]

Looks like it has been arcing. The body of the condenser requires a good ground. Is it mounted to fresh paint by chance so the bracket is not grounded?

 

Is the tower on the coil leaking high voltage to the (-) coil terminal when it fires? If it is cracked that can happen. Sounds like you have another coil so try swapping it out.

 

Garry

[tunahead72 2,545]

I'm really curious how this problem turned out...  @RetroMower do you have an update?