1983 XS650 diifculty starting the engine.

[shade]

I've been working on this bike for over a year, with the help from the great people on this forum. I've got the bike running and have ridden it a bit but I'm having difficulty starting the bike whenever it's been sitting for a while and sometimes even once it is warmed up. I am worried about taking the bike too far from my garage until I figure out what this problem is. Any suggestions?
You can see everything I've done here:

http://www.xs650.com/forum/showthread.php?t=27873

Thanks

 

[retiredgentleman]

I've been working on this bike for over a year, with the help from the great people on this forum. I've got the bike running and have ridden it a bit but I'm having difficulty starting the bike whenever it's been sitting for a while and sometimes even once it is warmed up. I am worried about taking the bike too far from my garage until I figure out what this problem is. Any suggestions?
You can see everything I've done here:

http://www.xs650.com/forum/showthread.php?t=27873

Thanks

I'm too lazy to go back through a long thread, but I have some advice. The voltage is super important on these bikes. You want to use a good strong battery (capacitor ?) and have a charging system that outputs 14 volts when at 3000 to 3500 rpm.

If its hard to start when the engine is cold.......................have you confirmed that the small orifice (jet) in the bottom of the carb bowls is clear. That is the source of fuel for the choke so it must not be blocked.

How old is the ignition system...............if its really old, just replace it.

 

[shade]

I'm too lazy to go back through a long thread, but I have some advice. The voltage is super important on these bikes. You want to use a good strong battery (capacitor ?) and have a charging system that outputs 14 volts when at 3000 to 3500 rpm.

If its hard to start when the engine is cold.......................have you confirmed that the small orifice (jet) in the bottom of the carb bowls is clear. That is the source of fuel for the choke so it must not be blocked.

How old is the ignition system...............if its really old, just replace it.

The battery is new, the ignition system is quite old. Since starting this thread I've cleaned the carburetors again. I noticed they were dirty again when I removed them, so I've replaced the fuel filter too.
I replaced the rubber carb holders as well.
The bike started up much faster than usual so I'm guessing the jets were clogged in the carburetor. I'm hoping the new filter helps.
I will read up on replacing the ignition system.
Thanks

 

[TwoManyXS1Bs]

... having difficulty starting the bike whenever it's been sitting for a while...

Been there. You may want to start using fuel stabilizers. Try forum search terms: "ethanol" and "gasohol" and "sta-bil" and "stabilizer".

 

[retiredgentleman]

The battery is new, the ignition system is quite old. Since starting this thread I've cleaned the carburetors again. I noticed they were dirty again when I removed them, so I've replaced the fuel filter too.
I replaced the rubber carb holders as well.
The bike started up much faster than usual so I'm guessing the jets were clogged in the carburetor. I'm hoping the new filter helps.
I will read up on replacing the ignition system.
Thanks

A new battery won't last very long, if the charging system is not producing 14 volts. Use a VOM and measure at the battery terminals.

There should not be any guessing about jet cleanliness. When you had the carbs apart, you should have removed the jets, and a careful eyeball inspection would have seen if they were blocked or clear.

Old ignitions are bad news.

 

[shade]

Thanks I appreciate the help.
I had cleaned the jets thoroughly the last time I took the carbs off. When I put on the new petcock I forgot it didn't have a built in filter and some crap must have clogged up the jets. I think the new filter will help.
Thanks.

 

[XSLeo]

The jet that feeds the enrichener is not removable. It's pressed down in a drilled passage in the float bowl.
If draws fuel in through a hole in the float bowl.
I don't have a pic but I'm sure someone else has.
Leo

 

[shade]

The jet that feeds the enrichener is not removable. It's pressed down in a drilled passage in the float bowl.
If draws fuel in through a hole in the float bowl.
I don't have a pic but I'm sure someone else has.
Leo

Thanks for the info. I blow that out with a compressor when I clean out the carbs.
The bike is starting regularly now for the first time.
As soon as one problem gets solved one or two more develop!

 

[shade]

I haven't been doing much with my XS650 over the winter because I don't live that close to where the bike is. I will be there more in the summer...
I did manage to get to it about once a month and start it but it slowly became more and more difficult to start over the winter. I put in on a charger whenever I was there and added fuel stabilizer to the gas. I am guessing the carbs need to be cleaned again, and some new gas will help.
I have had trouble with this bike starting consistently since I got it running last year and I'm wondering if this would help: https://www.mikesxs.net/product/17-6803.html
I put a new battery on the bike last summer...
Thanks

 

[5twins]

Varnish in your carbs is like an infection. If you don't get it all out, it will "grow" back faster the 2nd (or 3rd) time, and you never get it all out. I'm not sure you're clear on the choke feed jet. Here's its location .....

..... and here's how to verify that it's clear .....

 

[shade]

Varnish in your carbs is like an infection. If you don't get it all out, it will "grow" back faster the 2nd (or 3rd) time, and you never get it all out. I'm not sure you're clear on the choke feed jet. Here's its location .....

..... and here's how to verify that it's clear .....

Thanks 5Twins. The last time I cleaned out the carbs I blew out the choke feed jet well, but I will take them off and clean them again this time really focusing on that jet.
Thank you.

 

[5twins]

Being near the bottom of the float bowl, if any crud forms or gets in there, this is like the first jet to get plugged. When you activate the chokes, they suck fuel in through this jet, and any crud that happens to be in the bowl with it.

 

[nj1639]

Try to find 'Curlys charging system guide'......it's in the tech section I believe. Go through the charging system and confirm if it's good or bad........and save 5twins carb bowl pic until it's second nature.

 

[XSLeo]

Starting a engine every month or so and letting it idle for a few minutes is about the worst thing you can do to an engine.
Even if the charging system is up to it's job it can't recharge the battery enough, so slowly the battery goes dead. As the battery voltage drops the TCI will stop working. Often poor idle and no power on reving.
Combustion creates water and other acids that collect in the oil. The engine needs to run long enough at highway speeds to boil these contaminates from the oil.
A few minutes of idling won't get rid of this, just create more.
Leo

 

[shade]

I cleaned the carbs again, this time paying special attention to the choke feed jet. The bike starts much easier now but is backfiring through the carbs a little bit.
Thanks for the choke feed jet advice, I wasn't getting that thoroughly clean.

 

[shade]

Thanks 5Twins. I gave up on the floats bowls and ordered a new (used) pair. Once I switched them out the bike starts consistently. While riding this morning, I noticed the engine revving to around 3000rpm anytime I put it in neutral and I think when I was switching gears.