What have you done to your XS today?

[atom4488]

I'm all about checking the ignition first. One of my favorite sayings is never underestimate the ignitions ability to fool you into blaming the carbs.

Having said that.... we're talking a wasted spark system here. The list of things ignition related that can cause a one side only misfire are pretty small....
Plugs, caps and HT leads.... and the leads are a stretch. All that's been changed and some.

As long as Adam reports the problem only on the left side... well... these aren't the droids your looking for.

I had lost sight of the fact that it is only affecting the left side... that said, it makes the issue all the more perplexing. As I understand it, the problem is run-time-dependent, so what changes from idle to running within the first few miles /minutes?
- does the behavior move from left to right if you swap the spark leads? To me, if it doesn't, that may eliminate the ignition system as the source of the issue. So:
- manifold vacuum leak on the left side?
- fuel supply issue on the left-side carb? Restricted petcock / filter etc? Something that causes the left-side carb to run dry or low?
- float bowl venting restricted on left-side carb?
- Other ideas from the collective?

 

[atom4488]

Working an my newly acquired '80 XS, prepping for a roadworthiness inspection. It needs to conform to norms that are set out in Ministry documents.
- replaced the abbreviated front fender with a stock full-length fender
- removed the side-mounted license plate frame, to be replaced by a centrally-mounted plate mount in the normal location
- machined some aluminum spacers for the rear shock mounts to replace the washer stack
- test-fitted a stock rear fender, which will not work. It interferes with the electronics tray under the seat. New solution to be found
- tried to remove the Kellerman pin lights but ran into connector issues. Appreciate any help the collective may offer (see my connector thread of today)
I will need to add a chain guard, more conventional front indicators, larger mirrors, possibly other stuff. Here is the staring point:

 

[azman857]

Nothing much. Just rode her to Bike Night at the Barrio Brewery. Met with other members of the Tucson Vintage Motorcycle Riders. Tomorrow is CSA's bike night. I plan on going. It's just up the street.

 

[Raymond]

Working an my newly acquired '80 XS, prepping for a roadworthiness inspection. It needs to conform to norms that are set out in Ministry documents.
- replaced the abbreviated front fender with a stock full-length fender
- removed the side-mounted license plate frame, to be replaced by a centrally-mounted plate mount in the normal location
- machined some aluminum spacers for the rear shock mounts to replace the washer stack
- test-fitted a stock rear fender, which will not work. It interferes with the electronics tray under the seat. New solution to be found
- tried to remove the Kellerman pin lights but ran into connector issues. Appreciate any help the collective may offer (see my connector thread of today)
I will need to add a chain guard, more conventional front indicators, larger mirrors, possibly other stuff. Here is the staring point:

View attachment 252144

Seems a shame - you bought the bike 'cause you liked the style, but now you've got to change a lot of it back to standard. Do you have inspection places which are less by-the-book? Maybe scope for making just temporary changes for the inspection then revert to as-is?

 

[atom4488]

Seems a shame - you bought the bike 'cause you liked the style, but now you've got to change a lot of it back to standard. Do you have inspection places which are less by-the-book? Maybe scope for making just temporary changes for the inspection then revert to as-is?

Like your perceptive take on this!!! The mods being done a strictly to get it through inspection. Once inspected, it goes back to the shop to get restored to as-bought or better. In QC, there are lots of things that are done by anything other than the book. Oddly enough, vehicle inspections is not one of them!

 

[Adamc]

Like your perceptive take on this!!! The mods being done a strictly to get it through inspection. Once inspected, it goes back to the shop to get restored to as-bought or better. In QC, there are lots of things that are done by anything other than the book. Oddly enough, vehicle inspections is not one of them!

Thats a great attitude to take; make the bike your own! After all it only stays legal on the day of the inspection; anything can happen immediately after you drive away from the test center!

 

[Raymond]

Back in days of yore - well, actually 2004 - used to give a chap with a m/c business a hand which sometimes meant taking bikes for MoT. Place we used to take 'em near Southampton was quite happy for me to turn up on a sportsbike with a noisy exhaust, plus the original silencer (carried in me rucksack) place that on the floor next to the bike and, well, a nod's as good as a wink to a blind horse.

 

[Dunc]

Got it fired up today & tried the fairing.

 

[Oldfartaussie]

I was out riding the countryside back roads and after 130 miles or so I stopped for fuel then after when going through the gears I was getting a few false neutrals changing up and down through the country towns. It then started jumping out of gear in every gear with false neutrals between every gear. Even nursing it home it would jump out of top gear while accelerating.
Made it home and removed the clutch case and sure enough found a broken spring on the selector drum with the small hook broken off the end and nowhere to be found.
I've taken the clutch out and the selector shaft, removed the base plate off the sump and strained the oil but no sign of the small hook off the spring.
I've ordered a new spring but should I try and flush the engine to find the missing hook?

 

[Dunc]

Have a good poke around with a magnet to see if you can find the bits.

 

[Bob Wegman]

I was out riding the countryside back roads and after 130 miles or so I stopped for fuel then after when going through the gears I was getting a few false neutrals changing up and down through the country towns. It then started jumping out of gear in every gear with false neutrals between every gear. Even nursing it home it would jump out of top gear while accelerating.
Made it home and removed the clutch case and sure enough found a broken spring on the selector drum with the small hook broken off the end and nowhere to be found.
I've taken the clutch out and the selector shaft, removed the base plate off the sump and strained the oil but no sign of the small hook off the spring.
I've ordered a new spring but should I try and flush the engine to find the missing hook?

I had the same spring break on one of my XS650s. Found all the pieces though. Best of luck with your search.

 

[Dunc]

A bit more today

 

[magoo66]

Preserving a spare 79 tank just in case.Cleaning and testing before any more paint preparation or paint.

 

[Toro]

Getting it re-phased?

I don’t think I’ll do a re-phase, instead probably just get new 447 rods and matching pistons

 

[atom4488]

Working an my newly acquired '80 XS, prepping for a roadworthiness inspection. It needs to conform to norms that are set out in Ministry documents.
- replaced the abbreviated front fender with a stock full-length fender
- removed the side-mounted license plate frame, to be replaced by a centrally-mounted plate mount in the normal location
- machined some aluminum spacers for the rear shock mounts to replace the washer stack
- test-fitted a stock rear fender, which will not work. It interferes with the electronics tray under the seat. New solution to be found
- tried to remove the Kellerman pin lights but ran into connector issues. Appreciate any help the collective may offer (see my connector thread of today)
I will need to add a chain guard, more conventional front indicators, larger mirrors, possibly other stuff. Here is the staring point:

View attachment 252144

Carried on with the roadworthiness inspection mods. Some I don't mind doing, others are hideous and are spoiling the look of the bike. I need to keep in mind that most of these mods are temporary and all of them are reversible.
- replaced the Kellermann pin lights with some larger generic LED indicators
- fabricated a mounting bracket for side reflectors
- replaced the mirrors with larger generic bar-end mirrors (the bar-end mount may still be a cert issue)
- pinched the chain guard from my 650D and installed it on the SG (requires taking the shock out of its lower mount, which revealed that there were no steel bushings in there)
- turned up and installed a set of lower shock eye bushings
- started the installation of an odd-ball (non-XS) rear fender (this bit is truly aesthetically offensive!!!)
More to follow, including pics. Still need a conventional tail light, license plate mount and lights.

 

[bosco659]

I took the old girl out for a ride today and it’s probably the last for this season. Topped up fuel along with stabilizer (perhaps unnecessary); drained carbs and fuel bowls, then did an oil change. Pretty much ready to put yo sleep for the winter. Prior to storage I may remove some bits for winter polishing and I’m still threatening to attempt a hydraulic clutch conversion but that’s getting kinda low on the priority list right now. Just as I left the gas station the odo turned 5,000 km. That’s mileage since it was completely rebuilt. Checked plugs and they looked pretty good too.

 

[Commuter]

Am taking my time with this bike. I decided to check the points and timing today. I check the points with a dwell meter and it works very well. The point were absolutely spot on with the 4 cylinder dwell meter reading 22.5 degrees. I took the time to mark the timing marks with a white tyre marker pen and then emphasise the actual marks with a fine tipped black permanent marker. It was a worthwhile thing to do since the timing was 2 degrees over advanced. While I was at it I had previously noticed an inballance of the sounds coming out of the exhaust so I pulled the plug out of each float chamber in turn in order to check whether both carbs were holding the same amount of fuel... the float height for the left and right are as near as makes no difference the same. I fitted vacuum gauges and found that theres a wide variance with the left hand side varying but the right hand side not varying at all. There's got to be an air leak on the right hand side. either the diaphragm or the manifold gasket I suspect. I've bought new manifold heat shields which need fitting and so the carbs have to come off anyway but that's a job for another day. By the way, I went to a lot of trouble to get vacuum take off spigots on a 38mm manifold and this does make life a lot more simple when analysing potential issues. It also gives me more accurate methods to set the carbs up.
Many years ago, I watched a guy at the dealers set my 650 motoguzzi up on vacuum gauges. He explained that this has to be the very last job since valve timing, tappets, ignition timing, mixture all effect the carb ballance. On completion, the bike started perfectly, ticked over at almost impossibly low revs, picked up without issue, rode very smoothly and also seemed to make more power ( although I have never actually seen any actual proof of this). So.... every bike I've had after that 1986 Moto Guzzi 8 valve V65 has had to have its carbs ballanced. Incidentally, I've also checked the ballance on modern fuel injected bikes I've owned and found them all to be spot on. I routinely use the dial gauge type of vacuum gauge. People often critisise this type of gauge saying they're not accurate. They are right about that but in the case of a twin, all you have to do is swap the vacuum pipes with each other in order to ensure that both gauges read the same. Ballancing does not rely on whether what the gauge reads...just that both gauges read the same all the time whether ticking over , accelerating or high revving. Even having a faulty seal on an air filter can upset the ballance.
Some say that carb ballancing is nit picking....they're quite right , it is nit picking but when I've ridden something which is as good as it can be, I am reluctant to revert to average. Tomorrow's another day ...plenty of time to get it right.

 

[Adamc]

Am taking my time with this bike. I decided to check the points and timing today. I check the points with a dwell meter and it works very well. The point were absolutely spot on with the 4 cylinder dwell meter reading 22.5 degrees. I took the time to mark the timing marks with a white tyre marker pen and then emphasise the actual marks with a fine tipped black permanent marker. It was a worthwhile thing to do since the timing was 2 degrees over advanced. While I was at it I had previously noticed an inballance of the sounds coming out of the exhaust so I pulled the plug out of each float chamber in turn in order to check whether both carbs were holding the same amount of fuel... the float height for the left and right are as near as makes no difference the same. I fitted vacuum gauges and found that theres a wide variance with the left hand side varying but the right hand side not varying at all. There's got to be an air leak on the right hand side. either the diaphragm or the manifold gasket I suspect. I've bought new manifold heat shields which need fitting and so the carbs have to come off anyway but that's a job for another day. By the way, I went to a lot of trouble to get vacuum take off spigots on a 38mm manifold and this does make life a lot more simple when analysing potential issues. It also gives me more accurate methods to set the carbs up.
Many years ago, I watched a guy at the dealers set my 650 motoguzzi up on vacuum gauges. He explained that this has to be the very last job since valve timing, tappets, ignition timing, mixture all effect the carb ballance. On completion, the bike started perfectly, ticked over at almost impossibly low revs, picked up without issue, rode very smoothly and also seemed to make more power ( although I have never actually seen any actual proof of this). So.... every bike I've had after that 1986 Moto Guzzi 8 valve V65 has had to have its carbs ballanced. Incidentally, I've also checked the ballance on modern fuel injected bikes I've owned and found them all to be spot on. I routinely use the dial gauge type of vacuum gauge. People often critisise this type of gauge saying they're not accurate. They are right about that but in the case of a twin, all you have to do is swap the vacuum pipes with each other in order to ensure that both gauges read the same. Ballancing does not rely on whether what the gauge reads...just that both gauges read the same all the time whether ticking over , accelerating or high revving. Even having a faulty seal on an air filter can upset the ballance.
Some say that carb ballancing is nit picking....they're quite right , it is nit picking but when I've ridden something which is as good as it can be, I am reluctant to revert to average. Tomorrow's another day ...plenty of time to get it right.

A paragraph or two would make easier reading.
But a good story so far..

 

[Grimly]

Some say that carb ballancing is nit picking..

Well, as soon as somebody says that, I disregard anything else they might say as that's likely to be just as wrong.

 

[Commuter]

A paragraph or two would make easier reading.
But a good story so far..

Having read many of the posts on this site, it is apparent that some people,despite having a great amount of enthusiasm, do not have an equal amount of comprehension. I appologise if the long winded nature of my written accounts appears arduous for those who are already very savvy.