Crappy bike won’t work

[Jay2903]

Hey guys
I feel like I’ve been fixing this forever.
It’s a Yamaha xs500 1975

I bought it ages ago and here’s the story.
A few months ago it I couldn’t getting running right after putting pods on it. I took it to a mechanic and he rebuilt and adjusted the carbs.
On the way home it didn’t feel that great, when I got home about an hour later I went to take it back out but it wouldn’t start. I put a new plug in and it seemed fine. I think took the engine apart to replace a gasket and reassembled it.

Today
I put a new set of plugs in (just for piece of mind), it started and idled fine this morning. I then got my gear on and went to go out on it an hour later, it started fine but then one cylinder stopped. It cut out then wouldn’t start again. I put another new plug in the left side and it was fine I took it around the block and came back.

This evening I went to use it and it wouldn’t start again. I pulled the plugs and rest them on the head to check. The left was not working again, i replaced it it with a new one then checked again. I then went to take it around the block but it didn’t make it 50 metres before dying. It wouldn’t start. I pulled the plugs and rest them on the head to check spark it looks fine.

I really feel like I’m going crazy.


At this point absolutely any help at all is greatly appreciated.

[Hawkeye1250FA]

HT leads? Or you bought a load of plugs from the same cheap ebayer and they are all shite? 🤣👍

Can't think of anything else immediately.
____________________
1993 RF400R - 2002 Bandit 1200 - 2012 1250 FA

[Raffles]

You're not trying to ride it 'warmed up' with the choke on are you?
____________________
A good loser will always be a loser.

[MarJay]

Take the pods off, put the airbox back on then try again.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Jay2903]

[Jay2903]

[Jay2903]

[mentalboy]

What are the points like? The XS was one of those machines that you had to open up the points on a frustratingly regular basis.
____________________
Make mine a Corona.

[Jay2903]

[mentalboy]

[Jay2903]

[Ste]

So let me get this straight, it started running badly after you took the airbox off and replaced it with pods but you haven't tried refitting the airbox to see how it runs?

At least give it a try if not just to eliminate it as the really obvious possible cause of the problems.

[P.]

Adding pods = nah.

Genuinely, revert to stock with airbox etc and that will work.

[Jay2903]

[Ste]

"I couldn’t getting running right after putting pods on it"

[Jay2903]

[Ste]

So there are no problems any more?

[Jay2903]

I think it’s an electrical problem. The carbs have been rebuilt and adjusted by a mechanic so I can rule that out. Timing and points are fine.
The problem is very intermittent. If it was a carb issue it would be a bit more constant.

[Ste]

The carbs being rebuilt and adjusted, was that when "on the way home it didn’t feel that great? ?

[Jay2903]

[pepperami]

Having been the unfortunate owner of both an XS250 and an XS 400 in the past, I can confirm that they seem to like to fire on only one cylinder for no apparent reason on a common basis.
My mantra was points, condenser, coils, HT leads, plug caps, and then plugs.
Most of the time I would find the problem somewhere in that lot.
After that it would be time to look at those stupid vacuum operated carbs and that stupid vacuum operated fuel tap
I ended up replacing the diaphragms on mine.
It’s an old bike and rubbery bits go all slurrrgh after that many years.

You could always do what I did to solve the problem ....... I got rid of mine ...... my life is a lot calmer now
____________________
I am the sum total of my own existence, what went before makes me who I am now!

[mentalboy]

[Jay2903]

[Jay2903]

[P.]

Did you add a fuel filter?