K181 Trouble Shooting

[Ty Fritz 8]

Please forgive the question, if it's been asked and answered.  I'm new to the site, and had trouble searching for an answer to my issues
I use my Wheel Horse B-80 all year round.  It started acting up a couple of weeks ago, first it would die while mowing.  I could restart it easily and finish the job.  A week ago it wouldn't start and had to use a battery charger because battery needed help.  It would run until it warmed up and die like you turned it off.  This is not normal for this unit, usually it starts right up, not continuously cranking. At that time I was thinking it was fuel delivery, so I bought a carb re-build kit (gaskets and needle valve), blew out the carb, put it back together.  Same thing, 10 minutes and done, won't restart.  Bought a new fuel pump, fuel lines, fuel filter, air filter and cleaned the tank and screen on the pet cock.  No change.  This weekend bought new points, condenser, plug and replaced the now toasted battery.  I was able to mow for 30 minutes then it died and wouldn't start.  Checked for spark again, nothing.  Replaced the coil and was able to finish the days toils, however it did die twice while using it and start right back up.  When it dies, it's a complete loss of power.  You would think it's fixed, but no.  Still dies after warming up.  Besides the part listed above that were recently replace, I've also replaced the rectifier, ignition switch and starter solenoid two years ago.  Any and all suggestions are welcome at this point, tired of throwing parts at it.  I need it ready for Indiana snow.

Thank you in advance,
Ty Fritz

[oldredrider 2,548]

Not trying to scare you about more parts, but it sounds like your coil is bad. A weak or bad coil does exactly like you are describing.

[WHX?? 48,815]

Hello Ty, Sounds like you already covered most of the bases already. Maybe try checking any & all safety interlocks. bypass ing them if possible to see if the problem goes away. Almost sounds like an electrical problem.  I'm not a B-80 pro so hopefully someone who is will chime in here.

 

[squonk 41,092]

First check the ammeter and connections. I have seen bad connections there that will kill the ignition. If you had a weak battery, excessive current thru the ammeter could have weakened the connections. If all is well there, I would replace the ign switch. Make sure it is the correct switch for battery ignition. The switches aren't real heavy duty and the contacts may be going.

Edited November 2, 2015 by squonk

[953 nut 55,210]

A few years back I had similar symptoms on my 312-8 and cured it with a new fuel cap, the vent was plugged on the old one. Hope this helps.

[stevasaurus 22,725]

It sure does sound like the coil.  The problem may be...now that you have fixed the issue...you may have created another one by rebuilding the carb, etc.  I think I would take a good look at the carb again at this point. 

[Ed Kennell 38,162]

I always go back to the equation   Compression + fuel + fire = a happy engine.
Assuming you have compression, My first check would be when it dies and refuses to start, try starting with starter fluid directly in the carb.  If it runs, you have a fuel delivery problem.  If it does not start, pull the plug and check for fire while cranking.  If no fire, you have an ignition problem. 

[skrusins 128]

I have a B80 that has the exact problem. You will not have a problem in the winter. When its warm my does the
same thing. I turn on the electric fuel pump on and it continues to run without any problems. As a matter of fact
it happened today for me. In the winter I never had to turn on the electric fuel pump. That is how I cured my problem.
Hope this helps. Summer Gas Winter Gas?

[Ty Fritz 8]

Thanks for so much feed back!  Playing taking a vacation day tomorrow and going to put your advise to work. Just for grins, I hit the key on the tractor tonight and it started right up without choking. I was suspicious so I turned it off and tried starting it. It took three different trys, but it did start. I let it idle for about 15 minutes, then took a couple fast laps around the house and parked it. It does start right up after it is warmed up. Going to re-seat all connections tomorrow, check all gaps, replace plug wire, go over all wiring and look for any scuffs that may be grounding out and other items that have been suggested. Gas cap vent is clear and unobstructed. I'll post my findings. 

[Ty Fritz 8]

OK. Here's what we learned today. When l started in on the tractor, I started working from the front. Points gap was fine. Pulled off the air filter cover to find it was soaked with fuel, along with the filter. Pulled the carb, drained it, pulled the bowl. While it was upside down to check the float adjustment, I noticed that float was laying on the carb body and needle valve was doing nothing, come to find out the new needle valve is 1/32 shorter then my old one (I keep everything). I took my stock clip off of the new needle valve and used the one provided in the kit. Had to make a minor float adjusment because of the different needle valve clip. Put back together, and runs like a champ. Turns over once and fires right up.  I chaulk this up to being in a hurry, thinking the all new parts were apples to apples. 

So no safety interlocks issues. Coil is good, also it has a internal resister with a resistive value of 3.2 to 3.5.  Keeping just below the 9.6v that I was concerned about. I didn't want to burn my points up. Stevasaurus, you were spot on. Thank you all though for your responses and guidance. 

Ty

[IH8RDS 18]

I was going to say the fuel pump because my b80 did the same thing this summer, but I see you replaced it already. Could be wire chaffing?!? Good luck.