C-160 not running smooth ??

[Fly by Nite 4]

Hi everyone my 1975 C-160 has this funny condition where it runs smooth has that nice Kohler K series sound and then like a light switch it sounds like it is taking on a load. this happens hot or cold high or low RPM actual load or not it does seem to run like this more than it does not.  when it is running I try choke, change throttle position has no affect i am suspect of electrical cuz it comes and goes so quick however all of the electrical components look good. I have not done anything with the carb yet ?? Just reaching out for ideas Thanks

[squonk 43,361]

If it still has an ammeter check that and it's connections. It is the first thing in line before the switch.

[ebinmaine 71,825]

3 minutes ago, squonk said:

If it still has an ammeter check that and it's connections. It is the first thing in line before the switch.

That was my first thought as well. 

Put one of the ammeter wires on the post of the other. This bypasses the ammeter. 

 

Also, 

We used to have a saying. 

You can't effectively do diagnostics until you do all maintenance. 

 

I agree that it's more likely electric. 

It's important to remember that these tractors use a DC system. Direct Current. 

A bad ground means a bad or no circuit. 

You'll want to remove, clean and reinstall the ends of ALL the wires and eliminate the possibility of an intermittent open circuit. 

 

[peter lena 9,188]

@  FLY BY NITE, think you running , vibrating engine is suggesting a wire chafing / shorting some ware in your  harness set up . tight bend wires , often crack and short out , as do chafing wires . would also check out related fuse areas , plug in terminals are known for electrical stress cracks, look for a powdery cracked line on both side of a plug in . pete 

[Jeff R. 35]

I am 80% sure that this is not your problem, but let’s take 15 seconds to rule it out.... how is the vent on the gas cap??

[peter lena 9,188]

@JeffR, might not be much , but if it gives you a response , bingo . usually throw a bunch of ideas  and try's at a  problem , what ever finds the response that verifies it , worth a try , pete  

[953 nut 59,243]

I agree that an electrical problem would be the most likely source of this problem. If you find a bad connection don't stop there, others are likely to be there too. Have you taken a look at your ignition points? A new set of points and condenser should also be considered.

[Moonshine*Connoisseur 466]

Double check your points gap. If it's off it will make the engine seem like its laboring or even run hot, like it's out of time.  Make sure the correct spark plug is in it as well. This is just one possibility of what it could be, good to check anyways. 

[Fly by Nite 4]

12 hours ago, squonk said:

If it still has an ammeter check that and it's connections. It is the first thing in line before the switch.

Thank you i did test with test harness that eliminates everything but the battery the only wire would be to the points i will look at that closer 

[Fly by Nite 4]

1 hour ago, Moonshine*Connoisseur said:

Double check your points gap. If it's off it will make the engine seem like its laboring or even run hot, like it's out of time.  Make sure the correct spark plug is in it as well. This is just one possibility of what it could be, good to check anyways. 

thank you i will double check

[Fly by Nite 4]

2 hours ago, 953 nut said:

I agree that an electrical problem would be the most likely source of this problem. If you find a bad connection don't stop there, others are likely to be there too. Have you taken a look at your ignition points? A new set of points and condenser should also be considered. Thank you i did not load test battery i will

 

[Fly by Nite 4]

8 hours ago, peter lena said:

@  FLY BY NITE, think you running , vibrating engine is suggesting a wire chafing / shorting some ware in your  harness set up . tight bend wires , often crack and short out , as do chafing wires . would also check out related fuse areas , plug in terminals are known for electrical stress cracks, look for a powdery cracked line on both side of a plug in . pete 

Thank You