C175 dies after warm-up under load

[c175inMA 8]

Hi all,

     So the KT17 in my C175 is acting up. It started after I had been mowing for about an hour on a hot day. The tractor was running hot and started to lose power, and eventually died. Now I can start the tractor and mow with it for about two minutes before it bogs down. I can run it at idle, but it stumbles when I try to go to full throttle. I have never had any carb issues with this tractor, although it sounds like it is starving for fuel. I can see gas in my inline filter so i'm thinking the problem is electrical. Would the engine overheating cause this problem? Any other ideas? Thanks in advance, Paul

[smoreau 658]

Change the condenser , had this happen on one of my 417A tractors. I also changed the points while I was in there, but they looked good and were reinstalled on another tractor later on.

[JackC 616]

Points, condenser, and coil are suspects.  The engine manual provides test procedures for the condenser and coil.  The points may need to be adjusted or replaced.

Also check for good wire connections especially where the plug wires plug into the coil.

[Jeff-C175 7,195]

While I'm not saying it isn't ignition related, to me the problem sounds more like a fuel delivery issue... vapor lock?  main jet in carburetor dirty (while idle circuit is still functioning)...

[c175inMA 8]

Alright, so the manual says the points gap should be between .017" and .023" The engine only runs on partial choke when they're set in that range. They were set to .007" or so before i adjusted them. I will check the condenser and coils. Thanks for the input. It's much cooler here now, so i don't think it's vapor lock. I will check the ignition first. Thanks again.

[Jeff-C175 7,195]

I'm surprised it ran at all with them that close!  Mine didn't...  The manual for the KT actually says to use a timing light through that little hole on the rear side of the shroud... which I did one time but it's too hard for me to see.  Bottom line is that with the points set at .020 the timing was right on, so now I just set them and forget the timing light...

 

The fact that it runs with the choke partial is telling me it's fuel related, FWIW.

[c175inMA 8]

I has run with the points set that close for the past two and a half years i've owned it. It always ran fine, except once when the screws holding the air filter housing to the carb came loose and fell into the carb. They went through the carb and ended up holing the valves open so i had no compression. The reason i don't think it's fuel related is because it will run for a couple minutes at full throttle, choke off, deck engaged, before it dies.

[posifour11 723]

Kinda with Jeff, did you try it with the gas cap loose?

[JackC 616]

Fuel pump gaskets deteriorate faster when fuels with ethanol are used.  I just had to purchased a new vacuum fuel pump for my 520HC.  I use clear fuel line near the engine and after the filter so I can see when fuel is not getting to the carburetor.

[Jeff-C175 7,195]

Points too close means retarded timing... KT manual claims " overheating and loss of power "

 

Just keep an open mind when troubleshooting... close mind and say " it can't be that " leads to ghost chasing and wasted time.

[bubbacola 8]

  just had a problem like that on my C175 put points,condenser, coil in it and it did the same thing ran a little while started to lose power then die.   mine was a cloded fuel screen in gas tank

[boovuc 1,090]

I would also check for "frost" and or "condensation" on the intake manifold when it starts to "act up". My KT17 did that for a long time until I was able to finally find a small but big enough leak in the manifold. Once it was fixed, I had to basically retune the whole tractor. (Carb settings and points gap).

The PM or the dealer he took it to would just make little adjustments until it couldn't be adjusted anymore.