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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 26051
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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Here is the situation: 2003 mower with Honda GXV670 engine.

Customer Question

Here is the situation: 2003 Scag mower with Honda GXV670 engine. I am the original owner and I only use it on my lawn (residential use only). When the mower is hot, I cannot restart it without much noodling with the choke and praying. I don't know if it's the solenoid, control module, coils, choke, etc.
Submitted: 7 months ago.
Category: Small Engine
Expert:  Curtis B. replied 7 months ago.
Have you ever checked the valve clearance on the engine? Valves too tight can cause hard start when hot. See page 17 in the attached manual.
Expert:  Curtis B. replied 7 months ago.
http://cdn.powerequipment.honda.com/engines/pdf/manuals/37Z6E603.pdf
Customer: replied 7 months ago.
I haven't checked that yet. I've never done that before. Would they move over time? I only have about 500 hours on the mower.
Expert:  Curtis B. replied 7 months ago.
Yes valves wear over time and can close the clearance gap. Honda recommends every year or 300 hours.
Customer: replied 7 months ago.
Do I check the gap with a feeler gauge, like I would use on spark plugs? (the stick type, not the dial type obviously)
Expert:  Curtis B. replied 7 months ago.
Yes, a feeler gage. a stick type.
Customer: replied 7 months ago.
I hope that's it because it's probably the least expensive thing it can be. About how sure are you that's it?
Customer: replied 7 months ago.
Not challenging you by the way, just curious, based on your experience, how often that's the problem, etc. Thanks.
Customer: replied 7 months ago.
Also, how do I adjust? With shims? Or is it just a matter of a nut adjustment?
Expert:  Curtis B. replied 7 months ago.
This is twin engine , so it has dual coils, and both would not be failing at same time. and it starts when cold. So valves are a real possibility. I see it often on this site! And I have encountered myself first hand. i
Expert:  Curtis B. replied 7 months ago.
And it is a cheap fix. If not the valves, it can be the fule shutoff solenoid in the carburetor, that does not openas soon as it should.
Expert:  Curtis B. replied 7 months ago.
They have adjustment nuts and screws.
Customer: replied 7 months ago.
Any chance it's either the crank shaft sensor or cam shaft sensor. I didn't come up with those on my own. Also, can you tell me about the fuel shutoff solenoid in the carb? Is that something I can replace on my own? Or adjust on my own?
Expert:  Curtis B. replied 7 months ago.
It has no crank or cam sensor! Fuel solenoid just screws into the carb. It is anti-backfire solenoid, and plugs the main jet, it has to open as soon as the key is turned on. Has to have 12 volts to stay open.
Customer: replied 7 months ago.
That's good about the no crank or cam sensor. Thanks for the help. I'll try your suggestions. Have a good night.
Expert:  Curtis B. replied 7 months ago.
Thank you! Please ACCEPT to close and get me credit/
Expert:  Curtis B. replied 7 months ago.
Did you get to check the unit?