Honda XL500R starting problem

[john479]

Hi all,
I'm in need of a little advice on my XL500R restoration.

I can't get it to start or when it does, it only runs for 5 seconds. I've found that if I hold my manual decompression lever on and kick it over to prime it and then kick it, it sometimes does start but for only about 5 seconds. This makes it sound like a fuel problem but I've thoroughly cleaned the carb and used a good rebuild kit. It has a good spark and plenty of compression, so much that when trying a bump start, it locks the back wheel up. Tried a different CDI but exactly the same.

Anyone got any ideas?

Thanks,

John

[john479]

I'm getting good flow throught the petcock and needle. Can't see I have an intake leak as I've changed the o-rings on the rubber boot and spacer and they''re done up tight. Exhaust is fine as I tried it without the exhaust and it did the same thing - ran for a few seconds if I prime it with full choke, holding decompression lever in. Then big kick and it will start but die after a few seconds. Does behave like fuel starvation.

I'll try a squirt of easy start and see if it fires. Bike is 1982 so single carb

Thanks

[Andyvh1959]

When you say you cleaned the carb, did you actually completely disassemble it and clean all internal passages and jets manually? When I do this I use strands of copper wire pulled from 12ga or 16ga wire and I push it through all the jet holes and carb passages. Then I blast them all out with carb cleaner. Then I blast them all out with compressed air.

This is the only thorough way I know to really clean a carb. No amount of soaking or carb cleaner does it without actual breakdown and manual cleaning.

That said, is the float level properly set? Any internal screen/strainer in the carb cleaned? Is the fuel shut-off valve in the carb free to open and clear? That is the little valve above the float level arm.