Help needed on getting 86 YZ250 running

[balfred]

I have an 86 YZ250 that I have worked on restoring last winter and I cannot get the thing to run. My wife gave it to me for a project to keep me busy and it came not running and needed a pickup coil and a new top end. I replaced the whole ignition system with a new analog ignition kit and had the top end rebuilt and cleaned the carb and adjusted timing and a thousand other things it feels like. So I can't get the thing to run and it's frustrating me to see all the hard work go to waste, I really want to see it run. It's a cool old bike.

I'm hoping there is someone that would be willing to take a look at it for a bit that is more knowledgeable than me. I'm willing to pay someone to get it working or at least to tell me why it's not running and what it needs. So if you are good with old two strokes and feel the need to help a fellow RME guy out, let me know. I'm in west Jordan but can transport it around.

Thanks!

Bryce

 

[jeeper]

Does it give spark?
Will it fire from starting fluid?

 

[balfred]

It does have spark and it will fire with starting fluid. It's just hard to start and doesn't actually run

 

[jeeper]

Do you have good compression?
I would look at fuel delivery... Pilot jet especially. I will bet it is clogged.

 

[balfred]

It does have good compression. I did the clean the carb but I guess it's possible that I forgot the pilot, it's been so long so I don't remember. I think it has to do with timing and fuel potentially

 

[jeeper]

It's possibly timing, as you just changed it all.. but typically easiest fix is best to start with.. take the 30 minutes and clean the Jets and passages good.

 

[balfred]

Yeah I can try that. I hope that's it because I'm ready to roll it into a ditch haha. It's a love hate relationship

 

[Gravy]

Have you put a compression tester on it? How many PSI are you getting.

Pull the plug and see if you're getting a nice blue spark not a weak yellow one. Make sure your gap is good.

Check your timing and clean your carb really really good. Soak all the brass jets in amonia and spray out all the passages.

I like to blow apart the carb and soak it in 50/50 water and pine sol then wash it out with carb cleaner and blow out the passages with compressed air.

Check to see if the needle and seat are sealing and that your float is on the right way and set at the right height.

Make sure you jetting is what is recommended for your altitude.

Make sure you have no air leaks between the carb and motor and between the air box and air boot.