What have you done to your XS today?

[bazz]

Had a few hours this afternoon with perfectly sunny bike weather.
Thought it would be good to take Taffy for a shakedown run following the carb jet upgrades and coil treatment a few days ago.
That day Taffy fired up and idled& revved perfectly following the tweeks.

Today Taffy fired up and immediately misfired, would not hold idle and cut out at will. Adjustments to idle made no difference.
Even when warmed up it would backfire and cut out.

After several years and thousands of ££££ spent I'm at my wits end.
Only two trouble free rides in the years I have owned the bike.
I have lost patience and may sell at a huge loss going forward.

Sorry to hear this
It can get you like that sometimes
Don't give up mate

 

[grouchie83]

Took the cylinders to work to use a bore gage to measure them, at most I have .0025" over 75.000mm, so according to my manual I'm well within the wear limit.

Scoured the rust off with a scotchbrite pad, did a quick hone with some ATF, washed it off in the parts tank and wiped it down.

Scrubbed the cases some more in the parts tank.... someday I'll get the engine back together.

 

[Resto_Paul]

Retorqued head, case bolts, and cover bolts today, then checked valve adjustment. Tried to run a compression test but it was a stone cold engine and I couldn't hold the throttle open while I kicked it so I only saw about 115psi on each cylinder. Also made the test pipe below for my wideband but ran into idle AFR numbers that made no sense to me. Started another thread here on it but the long and short is I have the stock 42.5 jets in the carbs and unless I run the pilot screw 1/4 away from fully in my AFR at idle reads pig rich...like 12.5. However the exhaust doesn't smell rich and the plugs aren't fouling. Very confused.

 

[zrx1100]

Retorqued head, case bolts, and cover bolts today, then checked valve adjustment. Tried to run a compression test but it was a stone cold engine and I couldn't hold the throttle open while I kicked it so I only saw about 115psi on each cylinder. Also made the test pipe below for my wideband but ran into idle AFR numbers that made no sense to me. Started another thread here on it but the long and short is I have the stock 42.5 jets in the carbs and unless I run the pilot screw 1/4 away from fully in my AFR at idle reads pig rich...like 12.5. However the exhaust doesn't smell rich and the plugs aren't fouling. Very confused.

12.5 is not rich. Target 13 for idle. At wide open between 11 and 12

 

[Resto_Paul]

12.5 is not rich. Target 13 for idle. At wide open between 11 and 12

I always thought idle should be as close to 14.7 as possible....maybe slightly more rich

 

[zrx1100]

I always thought idle should be as close to 14.7 as possible....maybe slightly more rich

That is stoichiometric. This AFR ratio will melt pistons on an air cooled bike. 13 at idle, above 12 until wide open. Then between 11 and 12. The lower AFR at wide open cools the piston and will actually produce more horsepower

 

[Resto_Paul]

That is stoichiometric. This AFR ratio will melt pistons on an air cooled bike. 13 at idle, above 12 until wide open. Then between 11 and 12. The lower AFR at wide open cools the piston and will actually produce more horsepower

Thanks for the tips. I'll go back at it Monday now. From what I've read I'm guessing I'm going to need the next size up pilots anyway from stock. Im tempted to just drill the new set of stock jets bigger since I have my originals too

 

[zrx1100]

Thanks for the tips. I'll go back at it Monday now. From what I've read I'm guessing I'm going to need the next size up pilots anyway from stock. Im tempted to just drill the new set of stock jets bigger since I have my originals too

Your AFR is way too far back. Needs to be close to the head. Either a few inches out before the first bend in the headers or a few inches after the bend. Also place the sensor before and far away from any non-welded joints in the exhaust. The joints will suck in oxygen. And there will be more oxygen mixed in the further down the pipe you go

 

[zrx1100]

Thanks for the tips. I'll go back at it Monday now. From what I've read I'm guessing I'm going to need the next size up pilots anyway from stock. Im tempted to just drill the new set of stock jets bigger since I have my originals too

Here is my setup. https://www.xs650.com/threads/wideband-sensors.66143/page-2#post-844888

 

[zrx1100]

Retorqued head, case bolts, and cover bolts today, then checked valve adjustment. Tried to run a compression test but it was a stone cold engine and I couldn't hold the throttle open while I kicked it so I only saw about 115psi on each cylinder. Also made the test pipe below for my wideband but ran into idle AFR numbers that made no sense to me. Started another thread here on it but the long and short is I have the stock 42.5 jets in the carbs and unless I run the pilot screw 1/4 away from fully in my AFR at idle reads pig rich...like 12.5. However the exhaust doesn't smell rich and the plugs aren't fouling. Very confused.

a nice collection in the garage! what is the hot rod under the cover?

 

[Resto_Paul]

Your AFR is way too far back. Needs to be close to the head. Either a few inches out before the first bend in the headers or a few inches after the bend. Also place the sensor before and far away from any non-welded joints in the exhaust. The joints will suck in oxygen. And there will be more oxygen mixed in the further down the pipe you go

I know it's not ideal but I thought if there were no leaks and 18-24" of pipe after the heated sensor it would be fairly close still. When I tuned the hotrod (34 Ford pickup with sbc and tripower) I ran a pipe off the collector and got good readings.

 

[Dunc]

So I've fitted an XS400 rear wheel into the Motolanna swingarm. It has cush drive now & lines up straight with the front sprocket.

 

[zrx1100]

I know it's not ideal but I thought if there were no leaks and 18-24" of pipe after the heated sensor it would be fairly close still. When I tuned the hotrod (34 Ford pickup with sbc and tripower) I ran a pipe off the collector and got good readings.

I see the sensor is next to a joint. That is probably leaking. Here is a good video explaining this

. You may have a problem running rich if you are reading 12.5 with this setup. How do your plugs look?

 

[Adamc]

Sorry to hear -And I know the feeling .when things don't work out
And this is surprisingly difficult the same manifestations Effects can have many Causes
But never the less one effort not reaching the solution .. Is a Increased knowledge base
A platform for trying something else ... Been there done that

Apologize if I am not updated .. and dont remember what have been done

For thinking out loud If i Recall right You have the old mechanical Voltage regulator
That I have had problems with Upsetting the Boyer Ignition
It gave out to high Voltage . Once warmed up .I dont know if it shorted somewhere else but the Boyer Dumped one cylinder
A problem that disappeared with more modern regulator and rectifier .. Of the type described here on the forum

I am of the personal view that the more modern ignitions can have problems on these bikes
The Gonzo crowd have it and Bjorn in Holland had it with another GizmoBongBong After market electronics

These bikes never was designed for anything other than points and sparks at the alternator brushes

That may well create voltage spikes into the harness that a Microprocessor in these black boxes are not able to cope with
Please note that this is my View and can be entirely wrong Just putting it out here . The electronics work at the bench in the electronics
air conditioned clean room laboratory But water heat vibration spikes .etc

If I am not off so far
I would try new Regulator / Rectifier that is not so expensive se if that makes any difference

After that I would consider Boyer Bransden and hook it up via the battery bypassing the rest
with a switch since the Coil must be switched off If that makes any difference the knowledge platform
is again better

Again it is difficult just putting it out here .For Discussion and Thoughts
Dont remember if there is a Voltage meter on the Machine that was how i Discovered the over charging mentioned above

Hey Jan,
Thanks for the sympathy and kindness.
I have a 1980 model with standard charging system; a all in one regulator / rectifier unit, TCI (or Gonzo GN250 box).
All systems are through a Motogadget M-Unit (Non Blue).
Maybe you are correct regarding old charging systems upsetting modern control boxes.
I have decided to engage the services of a professional auto electrician (for bikes) to diagnose if I have an electrical issue.
I am much calmer now, and my wife had wise words "You won't get much for it if it isn't running right will you!"
So Taffy has a stay of execution.............. For now.

 

[Resto_Paul]

I see the sensor is next to a joint. That is probably leaking. Here is a good video explaining this

. You may have a problem running rich if you are reading 12.5 with this setup. How do your plugs look?

I used sealer on the joint and feel no leak. Plugs looked ok....not fouling just some black soot on the firing ring. After messing with it yesterday they were a little wet but I fiddled a lot

 

[Adamc]

Sorry to hear this
It can get you like that sometimes
Don't give up mate

Thanks Bazz, but on Friday I had almost committed Hara-Kiri around the bike.
Today is a new day and a new plan has emerged.
Watch this space
Ads.

 

[Raymond]

I have decided to engage the services of a professional auto electrician (for bikes) to diagnose if I have an electrical issue.
I am much calmer now,

I think it'll be worth whatever it costs to prove you're not going mad.

 

[Its been a long time]

No pictures today. Ran the 650 on the left cylinder with the right side spark plug removed and grounded. Started and ran easily on just the left side. The point being, I had so far been unable to check ignition timing with a timing light due to poor running on the right cylinder. In the event, the timing at ~1200rpm was about 4 or 5 degrees retarded. At 3000rpm also retarded. Adjusting the backing plate of the Boyer Bransden ignition got it spot on the F and a touch retarded at full advance. Ignition timing ticked off the list. Unfortunately, adjusting the timing has had no effect whatsoever on the badly running right cylinder.

 

[Its been a long time]

Hey Jan,
Thanks for the sympathy and kindness.
I have a 1980 model with standard charging system; a all in one regulator / rectifier unit, TCI (or Gonzo GN250 box).
All systems are through a Motogadget M-Unit (Non Blue).
Maybe you are correct regarding old charging systems upsetting modern control boxes.
I have decided to engage the services of a professional auto electrician (for bikes) to diagnose if I have an electrical issue.
I am much calmer now, and my wife had wise words "You won't get much for it if it isn't running right will you!"
So Taffy has a stay of execution.............. For now.

Wishing you all the best for a good outcome.

My 650 hasn't exactly been plain sailing. Owned it since December 2023 and haven't ridden it even once. I understand the frustration.

 

[zrx1100]

I know it's not ideal but I thought if there were no leaks and 18-24" of pipe after the heated sensor it would be fairly close still. When I tuned the hotrod (34 Ford pickup with sbc and tripower) I ran a pipe off the collector and got good readings.

See where S&S puts the bungs on similar bikes

Hey Jan,
Thanks for the sympathy and kindness.
I have a 1980 model with standard charging system; a all in one regulator / rectifier unit, TCI (or Gonzo GN250 box).
All systems are through a Motogadget M-Unit (Non Blue).
Maybe you are correct regarding old charging systems upsetting modern control boxes.
I have decided to engage the services of a professional auto electrician (for bikes) to diagnose if I have an electrical issue.
I am much calmer now, and my wife had wise words "You won't get much for it if it isn't running right will you!"
So Taffy has a stay of execution.............. For now.

That is when you sit back, crack open a beer and reclaim your Friday night watching motogp qualifying/practice.