How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Curtis B. Your Own Question
Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 13581
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
30244710
Type Your Small Engine Question Here...
Curtis B. is online now
A new question is answered every 9 seconds

I have a Toro mower with a Briggs and Stratton engine model

Customer Question

I have a Toro mower with a Briggs and Stratton engine model 128M02 3456-B1. I have used this mower for 4 years with no problems. Today it refused to start. I installed a new Champion RJ18LMC plug and when I tried to start it it backfires.
Submitted: 10 months ago.
Category: Small Engine
Expert:  Peter Bagley replied 10 months ago.

Hello and welcome to just answer and allowing me to assist you. have you checked for a good blue crisp spark, and is there any contamination in the fuel?

Customer: replied 10 months ago.
There is excellent spark and no gas contamination
Expert:  Peter Bagley replied 10 months ago.

ok thank you for that info/ next you said it back fires right

Customer: replied 10 months ago.
It did it twice.
Expert:  Peter Bagley replied 10 months ago.

a couple of things that will do that is timing, lean mixture . so when you try to start it do you chock it or does this have an auto choke

Customer: replied 10 months ago.
Auto choke
Expert:  Peter Bagley replied 10 months ago.

so are you trying to start it cold first when it back fires?

Customer: replied 10 months ago.
I has to be cold since I haven't started it.
Expert:  Peter Bagley replied 10 months ago.

ok then not being there I suspect that the auto choke is not closing enough to rich en the fuel to initially start it properly . Can you access the choke plate and see if it's closed fully or open/

Customer: replied 10 months ago.
It's open. I have the air filter out of it to confirm that.
Expert:  Peter Bagley replied 10 months ago.

so the choke plate is open, that may very well be our problem

does it seem stuck or just no spring tension on the plate

Customer: replied 10 months ago.
The choke plate is closed and it wont start.
Customer: replied 10 months ago.
What now?
Expert:  Peter Bagley replied 10 months ago.

sorry had a glitch on the sight and didn't allow me to respond

Expert:  Peter Bagley replied 10 months ago.

ok try a few times to start with plate closed and then take out the spark plug and see if it is wet with fuel or dry

Customer: replied 10 months ago.
The spark plug is wet.
Customer: replied 10 months ago.
Where do we go from here?
Expert:  Peter Bagley replied 10 months ago.

something is not adding up here first you said the choke was open then it was closed and you have a good spark and fuel but not trying to start? The fuel is new or was it sitting for a long time?

Expert:  Peter Bagley replied 10 months ago.

ok remove the spark plug and burn it off with a lighter and while it's still warm put back in and try

Customer: replied 10 months ago.
The fuel was purchased last Tuesday. The choke plate was closed. Sorry for the confusion. That's what I can't understand. I have fuel and spark but it won't start.
Expert:  Peter Bagley replied 10 months ago.

ok lets do this step by step, good fuel getting to engine , good spark.how old is this unit?

Customer: replied 10 months ago.
I removed the plug and and used a lighter to burn off any excess fuel. Replaced the plug and it still won't start. The mower was purchased new by me 4 years ago. I mow a large yard and buy new gas every week. I bought a new plug this morning and gapped it at .020 per the manual.
Customer: replied 10 months ago.
I pulled the starter cord with the plug removed and gas came out of the plug hole.