[SOLVED] 21 HP Twin will not run

[Pikman]

I have a 2005 Super Bronco with the 21 hp v-twin. I can dump gas into the carb and it will start right up until what gas I put in the carb is gone then it quits. I have taken the carb apart. I filled up a needle you use for refilling printers, and slowly run cleaner thru each hole and it seemed all was clear. Put the carb back together and will not start. Clean fuel filter, fuel pump is fine, and when I did take the carb apart I was careful and wanted to check if there was fuel in the bowl. Yes fuel in bowl.


Thank You....

[Basementgeek]

Hi and welcome to TSF

I would get a complete rebuild kit for the carb.

BG

[Pikman]

Thanks, I will try that.

[SlammedSdyme01]

Something is keeping the fuel from exiting the bowl. This is redneck trick but it helps, take a standard trash bag tie and light it on fire. When the coating is gone you're left with a wire that is perfect for cleaning passages. Use this to run through every passage in the carb paying special attention to the main jet and the main passage from the bowl. In my experience its usually one of those two with something still lodged in there causing the problem.

[Pikman]

I finally got my rebuild kit and still the same problem. This carb. is supposed to be self adjusting. There are no needle valves on the outside that you can adjust.

Thanks SlammedSdyme01, I will give that a try.

This problem really has me stumped. My Super Bronco is like new. In the winter months here in FL. we only mow once a month or less. I go out weekly and start the mower just to run it. This mower has never set out side when not in use. I wash it every other time I use it and wax it every other month. My yard is only 72 ft. wide and 65 ft. deep. It seems like it should be a easy fix.

Thank You guys for any info you give me. It all is worth a try....

[SlammedSdyme01]

All it takes is a little bit of dirt or varnish to get inside the main jet and fuel flow stops. Did your rebuilt kit come with a new jet (brass bolt in the bottom of the bowl)?

[Basementgeek]

Please give the model number off the engine. Once you get it running pick a can of
Sea foam:

Sea Foam | Motor Treatment

It will help to keep the fuel and fuel system clean.

Is the choke working OK ?

(Big mower, small yard :) )

BG

[jrrdw]

Do you here a click in the engine as soon as you turn the key to the run position? There is a "Anti-Backfire" solenoid screwed into the bottom of the bowl, if it's not working gas wont get through the main jet keeping the engine from running/starting.

[Pikman]

Basementgeek
Engine model #: 407577-0292-E1

jrrdw, I will listen tomorrow to see if there is a click.

SlammedSdyme01, no brass bolt.

Thanks.

Still not running

[Pikman]

Does not click. How do you bench test a solenoid? I am going to dis assemble the carb again and take the solenoid out to repair shop and buy a new one...

[jrrdw]

Touch the wire coming off the solenoid to the + on the battery and the threaded end to the - side of the battery and the plunger will move into the solenoid. When you disconnect it from the battery the plunger should pop back out. The plunger should be free moving.

If the solenoid heats up the coil is dead shorted and the solenoid needs replaced. If it does nothing it has a open circuit and needs replaced. If it moves slow or seems weak it probably can be cleaned where the plunger slides in and out with spray cleaner and test again.

It is not rebuild-able, they have to be replaced. Should cost anywhere in between 35 and 55 dollars.

[Pikman]

jrrdw: The solenoid was the problem. I have a new one on the way. I did take this one out and put a screw in it's place and it ran real smooth. With all the good tips from all the guys here the motor runs like it was new...

Thanks for all the help you guys I really appreciate it.

[jrrdw]

Congrats! Mark this thread solved please, it helps people know there is a solution to a problem they may be having.