New to me XS 650...

[Adamc]

I suppose one day I should break down and buy some real JIS bits too.
I've always just used a bench grinder and modified phillips bits. Never stripped a screw with these, so....
Yeah... I know... somebody flog me.


View attachment 199494

Jim you are a cheap tart! A clever one tho’

 

[Kevin Werner]

I finally had time, weather and al title health to get a ride today. Home team looked like crap so a ride to the old neighborhood seemed a good way to warm it up for the first oil change. I had not gone more than a mile thus far. My friend rode it around for a while and is now eyeing the H1 he has under blankets in his garage.
After returning I dumped the oil and filled with Walmart 20w50. Do I run that for a few miles and dump it again? There were some fillings in both magnetic plugs.

 

[fredintoon]

- - - After returning I dumped the oil and filled with Walmart 20w50. Do I run that for a few miles and dump it again?
There were some fillings in both magnetic plugs.

Hi tW,
Just filings? No chunks? Me, I'd run it ~500 miles to check on debris accumulation & on oil consumption.

 

[5twins]

I'd probably give it at least a few hundred miles, and get it good and hot before changing, not just a quick run around the block or a few minutes idling in the driveway. You want the tranny gears churning the oil around in there and hopefully that will break up and rinse out any sludge build-up. There's more than just checking the drain plug magnets, you should be pulling and inspecting both oil filters.

 

[Kevin Werner]

Thanks to Fred and 5TWINS. I will get 10-100 miles this year before the weather changes. So after a few spring rides, recheck.

 

[Jim]

Do I run that for a few miles and dump it again? There were some fillings in both magnetic plugs.

Ferrous or aluminum?
On "new to me" engine I'll usually put 20-30 miles on it, change the oil... which you just did.... and check for metal. If all that comes out is fine stuff I'll fill it and go another 100-250 and do it again. Hopefully after the second, the particles have gone down drastically. If it got dark again and/or had more particles, fill it and go for 500-1000 mi. Provided each change is better than the last, I'll go to a normal change schedule after the third time. That's all subject of course to no changes in motor sound, vibes etc.

 

[fredintoon]

Ferrous or aluminum? - - -

Hi Jim,
You got magnets that'll grab aluminum?

 

[Jim]

Hi Jim,
You got magnets that'll grab aluminum?

Hi Fred, you got magnets at the bottom of the sump that don't get sludge on 'em? The sludge can be full of particles and not have a ferrous bit in it.
Many's a time I've wiped off a magnet with my finger and not had any metal try and stay on it.... 'cause it was aluminum imbedded in the sludge.

But yeah... I figured some wise ass would pop off with that one.

 

[Kevin Werner]

This is represented as a fairly freshend unit. Maybe just Big Bore on a solid bottom end, but, it is smoother than I expected 41 year later. It pulls really well. It might have a bit rich jetting and I will at some point check the needle clips and see if I can drop them, the needle, a notch. I burbles a little at steady throttle 25 -45 mph. Higher speeds not so much as the load (drag) goes up. Am I thinking right there? After posting this I thought I instead could just run steady 45 on a county road for a few miles and then read the plugs, duh!

 

[fredintoon]

Hi Fred, you got magnets at the bottom of the sump that don't get sludge on 'em? The sludge can be full of particles and not have a ferrous bit in it.
Many's a time I've wiped off a magnet with my finger and not had any metal try and stay on it.... 'cause it was aluminum imbedded in the sludge.
But yeah... I figured some wise ass would pop off with that one.

Hi Jim,
wise ass? Me? I was trying to be helpful, eh?
I reckon the sump plug magnets are there to keep steel engine debris out of the oil pump.
And yeah, what mostly sticks to them is the same sludge that coats the rest of the engine's innards.

 

[Kevin Werner]

This is represented as a fairly freshend unit. Maybe just Big Bore on a solid bottom end, but, it is smoother than I expected 41 year later. It pulls really well. It might have a bit rich jetting and I will at some point check the needle clips and see if I can drop them, the needle, a notch. I burbles a little at steady throttle 25 -45 mph. Higher speeds not so much as the load (drag) goes up. Am I thinking right there? After posting this I thought I instead could just run steady 45 on a county road for a few miles and then read the plugs, duh!

I cleaned my plugs with alcohol and a toothbrush. The black soot washed off to a medium brown base. Maybe I ran with the enricher on. Today I ran a steady 50 mph, 3400 ish rpm for 3 miles, killed the engine and pulled off the road. Plug check showed black soot. I messaged the PO to see if he had any Jet info. I will remove the slides, check the needle height and try to identify the mainjet #s. Am I missing something?

 

[Jim]

steady 50 mph, 3400 ish rpm for 3 miles

At that engine load the needle's gonna have the biggest affect. I'd drop the needles one notch and try it again.

 

[Kevin Werner]

At that engine load the needle's gonna have the biggest affect. I'd drop the needles one notch and try it again.

How many notches are there on these needles? I am almost afraid they are at the lowest, that is why I hope to get jet # info from PO if he has it. I am just foolish enough to disassemble everything and leave it only to damage the paint or lose pieces. When it comes apart, I need to examine carbs and attend to charging. Then back together, a ride or 2 and into the barn for the winter.

 

[Jim]

5 slots iirc.
Just to clarify what I said previously... dropping the needle leans the mixture. To "drop" the needle, you "raise" the clip. Just reread my comment and realized I could have been clearer.

 

[Kevin Werner]

5 slots iirc.
Just to clarify what I said previously... dropping the needle leans the mixture. To "drop" the needle, you "raise" the clip. Just reread my comment and realized I could have been clearer.

You were clear to me, thank you.. I have been in and out of this kind of carb occasionally. I want less hole for the fuel to pass through . I accomplish that by more needle in the hole or smaller hole. If I am lucky, the clip will be in a lower slot and I will have a couple of steps leaner available.

 

[Jim]

Don't remember if the 38's will too, but on my BS34's I can pull the top cover and remove the slides without pulling the carbs off the engine.

 

[Kevin Werner]

Don't remember if the 38's will too, but on my BS34's I can pull the top cover and remove the slides without pulling the carbs off the engine.

Thanks Jim, I think the carb tops and ALL four screws are accessible after I remove the tank.

 

[5twins]

Cold starting with the choke will blacken the plugs and it can take a good run of several miles to burn them clean again. Your 3 mile jaunt may not have been enough. Yes, the needle has 5 slots. Stock position for your '76-'77 carb set is in the middle #3 slot .....

So, to lean it out, you would move the clip up to the #2 slot. As Jim said, raising the clip will lower the needle.

If your jetting has been changed from stock, usually richer for mods, then you often need to lean the needle a step. What you need to realize is that the 3 circuits in your carb overlap slightly. Changing one affects part of the one next to it .....

So, larger mains will make the upper part of your midrange richer and larger pilots will do the same to the lower part. You can pull the slides out to get at the needles with the carbs still in place. You can also access the main and pilot jets, just remove the float bowl with a stubby screwdriver. Here's a list of the stock jetting for you to compare to .....

 

[5twins]

Just looked at your pics on page 1 and see you have a very free flowing exhaust and pod filters. Chances are very good your carbs have bigger than stock jets but the needles may not have been leaned a step to go along with them. Really, you'll want to check all the jetting (and write it down).

Most of these 650s can get by with an increase of one or two main jet sizes for the typical "pipes and pods" mod. But your carb set is different. If you look at the chart I posted above and compare the main jet sizes, you'll see your carb set came with the smallest put in any 650 carb set. These small 122.5's work fine on an all stock machine but are easily and quickly outpaced when you start modding. Instead of one or two main jet sizes up, your carb set needs 3 or 4. Pilots will be OK with just one size up. But, going up so many on the mains, you really need to lean the needles a step.

 

[Kevin Werner]

To all who have offered insight, thank you. I do wonder if this is a stock jetting. I will only know when I open it up. It is a 750 kitted XS. Marvelously entertaining on the throttle.