1978 Xs650SE Barn Find

Yes Sir
Best running XS 650 I have ever heard -- Only joking
A little minor plopping .. on a cold engine been sitting for 10 years.
If the tank is clean and a couple of longer runs
Fresh gas Gone through we can consider the Points inspection.
# 39 Mr R Pyles above
Besides cleaning them ..
Nothing major yet.
Wont hurt to check the bolts on the exhaust.
And if you have a strobe light a quick check of the ignition timing.
I would be surprised if it is off
Is it easy starting ??
If you like you can upload a blipping of the throttle we can see if the timing is about right
On the response.
Stay cool and give the right blinker a kick upwards ( Joking again )

Jan-P - Tank was clean. It has not had a full tank through it ye and it starts easily, below is a little longer video, the backfiring sounds so much worse in person than it does on video. I can take a longer video tomorrow before I have to go into work again. I may ride the bike into work tomorrow depending how weather is that way I can see if the loose throttle bracket was my issue.

I dropped the bike on the lawn due to lawn being wet the other day when taking it out before blowing the fuses. I fixed the taillight today after taking the video.


Thanks,

Tim
 
Howdy Neighbor. I l,ive just up the road in Lebanon. Used to live in Norwich.
Good to hear from someone close by.
Have you read www.amckayltd/carngyide.pdf if not you may find it helpful with your carbs.
If you think your throttle cable is sticky, unhook it from the carbs. You can then move the lever the cable hooks to then release it to see if it's carbs or cable. Most likely the cable. With the cable unhooked you can oil it. In the book it describes the best way to oil the cables. I do it with the cables off the bike. I hang them up and make a kitchen foil funnel around the top. Might have to use some black tape to get a god seal to cable, Fill the funnel with motor oil. Let it seep down through the cable. Once it drips out the bottom it's well lubed.
This is even more important on the clutch cable. They need all the help they can get.
You can do this on the bike just by unhooking the cablers at both ends. It works. The motor oil works so much better than the spary can lubes with the cl;amp on the cable thing. The spray can lubes are to thin to lube well or last long.
I have one of those clamp o things. I use that to shoot cleaners through the cable. Carb, Brake, whatever, even WD40 will clean out the crud. Spray it in till it runs out the other end, let sit and repeat till what runs out is clear.
Maybe I'll see you on the road.
Leo
 
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On your loose bracket, being it is held on by the screws that hold on the top of the carb, the loose screws could have caused an air leak. So snugging them down just may fix it.
Leo
 
Howdy Neighbor. I l,ive just up the road in Lebanon. Used to live in Norwich.
Good to hear from someone close by.
Have you read www.amckayltd/carngyide.pdf if not you may find it helpful with your carbs.
If you think your throttle cable is sticky, unhook it from the carbs. You can then move the lever the cable hooks to then release it to see if it's carbs or cable. Most likely the cable. With the cable unhooked you can oil it. In the book it describes the best way to oil the cables. I do it with the cables off the bike. I hang them up and make a kitchen foil funnel around the top. Might have to use some black tape to get a god seal to cable, Fill the funnel with motor oil. Let it seep down through the cable. Once it drips out the bottom it's well lubed.
This is even more important on the clutch cable. They need all the help they can get.
You can do this on the bike just by unhooking the cablers at both ends. It works. The motor oil works so much better than the spary can lubes with the cl;amp on the cable thing. The spray can lubes are to thin to lube well or last long.
I have one of those clamp o things. I use that to shoot cleaners through the cable. Carb, Brake, whatever, even WD40 will clean out the crud. Spray it in till it runs out the other end, let sit and repeat till what runs out is clear.
Maybe I'll see you on the road.
Leo

Leo - Howdy Neighbor - I grew up in Earlville and used to live in Lebanon, Small World! I have read it - It helped me get this far with my bike. I will do some more troubleshooting tomorrow morning and report back.

Tim
 
Jan-P - Tank was clean. It has not had a full tank through it ye and it starts easily, below is a little longer video, the backfiring sounds so much worse in person than it does on video. I can take a longer video tomorrow before I have to go into work again. I may ride the bike into work tomorrow depending how weather is that way I can see if the loose throttle bracket was my issue.

I dropped the bike on the lawn due to lawn being wet the other day when taking it out before blowing the fuses. I fixed the taillight today after taking the video.


Thanks,

Tim

OK not the best running anymore
In my book that is a leaking exhaust ...
As first assumption Cant see what type of exhaust connections.
Or type
But with a little rich mixture ( Which is good ) and a leak the exhaust fluid via ejector functionality sucks in a bit more air
and since there is a little unburnt fuel it ignites in the exhaust
Then I would check the Ignition timing
And if none of those solves it I would wait until the Carburetor got some flexing and fuel through them
2 - 3 - 4 tanks and then reevaluate expecting it to get better under that driving.
Some dynamic revving up and down can help making things flex better ..
Not recommending faster that one feels safe about .But one way doing it
Is ---that en Route pulls the clutch in an twist a little taking care not to over rev
Half the red line would do it making slides and springs and whatnot to settle
But as first assumption leaking exhaust
 
Jan_P - Thanks for the insight. I have thought about replacing the carb boots, but am unable to find the correct ones for a 1978 as well as replacing the exhaust gaskets also.

My main goal was to get it running this past winter so I could ride this summer.

I am hoping this is a small issue that can be easily resolved.

Tim
 
There are Chemicals if one want to try that
If not a simple re tightening solves it .Dont tight to hard ..destroying anything

Like that ..
--> https://www.biltema.se/en-se/car---...systems-standard/mounting-adhesive-2000017097

The boots can be cracked and look awful but I have had those still not leaking
One can smear some kind of Gasket forming material on them and on the Sealing lips.
As well as on the gasket against the engine .New parts are of course good.
But the boots are Expensive.
But it is Possible to get going in this way.
I dont know what brands are Available for you .. .But Permatex makes products and Plastic Padding have chemicals
Both of which I have good experiences with.
If you explain the situation at the Auto Supplier he can sell you the right " Gluey stuff " "
Or even at the Gas Station.
And then upgrade next winter.
 
JAeeh well ..Not to give bad advice here
That is supposed to work and most likely does

Automobile
Suggested Applications: Valve covers, oil pans, intake manifold end seals, timing covers, differential covers

But chemicals and rubber is always a risk .. And at this point in time I believe it to be the exhaust system that leaks.
May I suggest that we wait with that for intake until the exhaust side is not leaking.
On the intake side there are some hose clamps and Allen bolts against the cylinder . please check those
And filter sealings.
But if I may suggest wait a while with the Permatex Black for intake

The above perhaps cant stand the heat on the Exhaust side

Automobile
Suggested Applications: Exhaust manifolds/headers, turbo charger applications, and slip-fit exhaust parts.
Motorcycle
Suggested Applications: Exhaust header flanges, slip fit exhaust pipes, and muffler end caps

https://www.permatex.com/products/g...aximum-temperature-rtv-silicone-gasket-maker/

I have not used it but it is a well known brand and they are recommending it . I believe cheaper brands can do it on the Exhaust side
If leaking there ... it is only a small leak.
Please touch the bolts and clamps first so nothing is loose

For Info
The one I have smeared on many gaskets since the 70 ies Not strictly the right one always
But it has worked for me.
https://www.permatex.com/products/g...ex-super-300-form-a-gasket-sealant/?locale=en
 
Afternoon,

Took bike for a 6 mile trip today. Bike rev'd through rpms like a normal bike would. I was surprised how quick it is. After I got back from the ride and bike was warm I tightened down the exhaust pipes at the head, the nuts were a little loose. I am still getting some backfiring. Below is a longer video with some throttle blips.


I hope to ride it tomorrow about 50 miles.

Tim
 
Sounds like either the pilot/idle circuit is restricted on one side... or maybe you just need to screw the idle mix screw out a bit. Holding your hand next to the exhaust should tell you which cylinder it is.
 
It does sound like you've got an air leak somewhere. Sharp pitched popping like that is usually a lean indicator. As the bike sits there idling, spray the intake manifolds with something like WD40. If the idle starts stumbling or the bike dies, you've found an air leak. I would also inspect the vacuum hoses running from your petcocks to the manifold, maybe one has split. Also check the vacuum nipples mounted in the manifolds. I had one come loose, pulled right out when I went to pull the hose off.
 
Not good
Mr 5Twins is perhaps the worlds best at this so I would go for that first
If you have something to spray with at home it is simple to do.
One thing I would do is to open the breaker point cover left side
And take a look inside when the bike is running see if any difference between sparks over the points gaps
I am still at an air leak but with a bit lesser strength

Since I don't know carburetors I wold then after the above
.jpg

shift over the spark plug caps and plugs
( are plugs replaced for new ? )
left over to right and right over to left and also shift the points leads
A picture of plugs out uploaded perhaps left and right.

If it is the left side running ok the shift should be so that the left side spark plug cap ,coil , contact breaker condenser
are installed to the right
And vice versa
If the misfire stays right or moves with the shift gives information
 
Thanks for the input Jim, 5twins and Jan. I put new plugs in yesterday. I have everything to remake the wires, just keep running out of time to replace them. I will spray some wd40 on boots tomorrow morning and will report back. Will it hurt riding bike as is?

Tim
 
Yes, if you still have the points ignition, bad condensers could be the problem, they'll cause misfiring and popping like that. Like Jan said, observe the points while the bike sits there idling. Look for excessive, constant sparking from the points faces. An occasional little spark is normal but constant big sparking is not.

Maybe you can hook up with Leo and he can help you out. You're very close to having this bike sorted, just a few little things left to work out.
 
I would not ride it ..as is
If it is a lean condition ... I know of people overheating and getting engine damage
This bike is to fine for that
 
I'd be willing to come look at the bike. I just have transportation issues at the moment. It's a bit cool and wet for the bikes. The Truck is waiting for some power steering hoses that should be in Monday.
If It stops raining enough to dry up some before The parts come in and I get them on the truck the bikes will be ok.
Leo
 
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