P500 2015 P500 Won't Run

[DG Rider]

Just because the plug is firing doesn’t mean a whole lot. I assume you pulled the plug and set it against metal on your bike. One thing to consider is your piston isn’t hitting your electrode on the plug. You would need to test with a spark plug tester that allows you to change the space between electrode and the ground. Set it to spec via probably repair manual. If it fires after proper space is set I would assume your ignition is fine. I would check battery first. Then fuel or ignition. If that fails to resolve the issue I reckon it’s electrical or god forbid timing.

???

 

[Chadmwallis]

Your engine must produce a certain spark length to ensure proper firing. A spark plug tester will adjust for the required gap. For instance a spark plug could spark if contact is to direct metal but when you apply the the recommended gap it might not fire. If there is a fault in the firing/ignition system or a battery that’s not up to par. A simple search of an adjustable spark plug tester may provide a better explanation than I’m able to give. Just the point that testing a plug that is laying against the engine(direct contact) and it sparks doesn’t necessarily mean you have a good spark.

 

[DG Rider]

Your engine must produce a certain spark length to ensure proper firing. A spark plug tester will adjust for the required gap. For instance a spark plug could spark if contact is to direct metal but when you apply the the recommended gap it might not fire. If there is a fault in the firing/ignition system or a battery that’s not up to par. A simple search of an adjustable spark plug tester may provide a better explanation than I’m able to give. Just the point that testing a plug that is laying against the engine(direct contact) and it sparks doesn’t necessarily mean you have a good spark.

The "spark length" is determined by the plug gap of the actual plug. Some testers have an adjustable gap, but this is to test the peak voltage the coil produces ( bigger gap requires more voltage ). This spec can sometimes be found in the service information, but watching the plug firing against the block is sufficient to give an ideal of what shape the system. A nice, consistent white/blue spark you can see and hear is a good sign everything is ok, while a weak orange or inconsistent spark would be suspect.

 

[Richd]

This is a long shot here but on many occasions on old dirt bikes etc...I've removed a spark plug grabbed it with a pair of pliers and heated it over a flame until it got red hot then reinstalled and started. It's an easy thing to try...never know what may happen.

 

[DG Rider]

This is a long shot here but on many occasions on old dirt bikes etc...I've removed a spark plug grabbed it with a pair of pliers and heated it over a flame until it got red hot then reinstalled and started. It's an easy thing to try...never know what may happen.

Brought some back to life myself that way...in a pinch. Seems like once they get fouled once, they are prone to do it again, though.

 

[Splorin]

Batteries are not to be trusted. They can just plain break. Clean connections and check voltage are the first steps these days on EFI rigs. Computer needs a 'happy' amount of voltage to satisfy start procedure. Batteries aren't getting cheaper,price wise that is....

 

[Rustneversleeps]

I can see it being a battery issue ..If it turns over must be something else...sounds like a electrical issue..

 

[Mudder]

This is a long shot here but on many occasions on old dirt bikes etc...I've removed a spark plug grabbed it with a pair of pliers and heated it over a flame until it got red hot then reinstalled and started. It's an easy thing to try...never know what may happen.

Had to do that often as a kid when my first $50 “dirt bike” had bad rings and would oil foul the plugs.

 

[Wallace]

Had to do that often as a kid when my first $50 “dirt bike” had bad rings and would oil foul the plugs.

View attachment 160163

305?

 

[Mudder]

Just grabbed a similar pic. Thinking it was a 1965 150 Dream?.. two cylinders but prior owner had but rings in wrong way. Bike was a step up from a mini-bike. So glad to have something with a clutch.

 

[Sr56]

My dad had a blue Honda similar to yours Mudder. I think it was a CB160. It had a really almost too soft suspension.


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[Mudder]

Update? Is it fixed?

 

[dannylj]

Put in the shop yesterday. He is going to drain the tank and put in fresh gas, put in new plug, and if necessary clean or replace injector. I should know something in a couple of days.

 

[dannylj]

OK, got the P500 back and about half you guys were correct although I'm a little embarrassed. Even though the old plug was firing, it was bad. A new plug fixed it like new. Cost me a total of $20. Thanks for all the replies.

 

[Mudder]

A service ticket at a dealer of only $20 might be a once in a lifetime blessing. Sounds like an honest shop. Glad it worked out.

 

[JimmyA]

A service ticket at a dealer of only $20 might be a once in a lifetime blessing. Sounds like an honest shop. Glad it worked out.

Kudos to the Shop!

 

[DG Rider]

OK, got the P500 back and about half you guys were correct although I'm a little embarrassed. Even though the old plug was firing, it was bad. A new plug fixed it like new. Cost me a total of $20. Thanks for all the replies.

Awesome. Sounds like your spark length was off...

 

[Wallace]

A spare plug is good insurance.

 

[Chadmwallis]

I’m glad you got it fixed. Dg rider I’m not sure if that comment was some sort of sarcasm referring to my post. I believe in this case a plug tester set to the appropriate length would have shown the plug was not firing sufficiently. Holding a plug against the block is not reliable. Except maybe a weed eater.

 

[DG Rider]

I’m glad you got it fixed. Dg rider I’m not sure if that comment was some sort of sarcasm referring to my post. I believe in this case a plug tester set to the appropriate length would have shown the plug was not firing sufficiently. Holding a plug against the block is not reliable. Except maybe a weed eater.

So...out of curiosity, what kind of plug tester do you use to test the plug?