Miss November XS2 tribute

[Rasputin]

Thank you, Machine. And Pete (we crossed in the post). Ahem, where was I?

Quick test run, only eight miles, bike running well, apart from that poppin' and bangin' on closed throttle.

Took the plugs out and I'm slightly puzzled:


View attachment 166850


Don't know how to read these. Is the bike running lean? The centre electrode is not covered in white ash, it just looks clean. Well, these were new plugs about 20 miles ago. There's some soot around the edge and the curved electrode does have some whitish residue.

Excuse my bluntness but, you can only judge the mixture by doing a correct plug chop. For mid range, a fairly straight slightly uphill road, constant just above half throttle for two or three miles. Clutch in kill the engine with kill switch. Coast to a halt, once in a safe place whip the plugs out and that should give you a clear indication of the mixture at that throttle opening. For the main jets same again only use full throttle. Idle mixture a bit more tricky, standard carbs etc generally run a tad rich at idle, a colourtune plug is handy to get near or verify the mixture.
Hope this helps. You are not alone. My plugs look a bit pasty/pale but it runs and pulls OK midrange so I’ll leave them alone.

 

[Jim]

Excuse my bluntness but, you can only judge the mixture by doing a correct plug chop. For mid range, a fairly straight slightly uphill road, constant just above half throttle for two or three miles. Clutch in kill the engine with kill switch. Coast to a halt, once in a safe place whip the plugs out and that should give you a clear indication of the mixture at that throttle opening. For the main jets same again only use full throttle. Idle mixture a bit more tricky, standard carbs etc generally run a tad rich at idle, a colourtune plug is handy to get near or verify the mixture.
Hope this helps. You are not alone. My plugs look a bit pasty/pale but it runs and pulls OK midrange so I’ll leave them alone.

I'll add to that... I always carry an extra set of plugs when I do a plug chop. Swap the plugs out and ride back home to read the color.

 

[5twins]

Yes, for testing specific carb circuits, a proper plug chop is best, but a general idea of how the bike is tuned can be had by just looking at the plugs. But I will add that if you do this right after a cold start using the choke, it will be misleading because the plugs will be black. The choke has done that to them, not the general tune of the bike. You'll need to take the bike for a ride (several miles at least) to burn the plugs clean again.

 

[Raymond]

All very good advice on plug chop & carb tuning. Much appreciated. Rasputin, no need to apologise.

Definitely give it a go. But might have to wait until the lock-down is ended. Or eased.

The UK government has relaxed the restrictions on driving, so it's probably ok to go out on a bike whenever you like. In England. But Scottish Government still telling people Stay At Home.

We're allowed out, supposedly once a week, to buy essential supplies. Whatever that means. One feels very conspicuous out and about on a bike. Naughty, almost. But we live in a rural village and I can justify going to nearby towns - Galashiels, Kelso, Hawick - where there are supermarkets. With a rucksack of course. I would be hesitant going much further than that. The worst that would happen is being stopped by the Police and asked why I'm out, etcetera. If in their opinion you are flouting the rules, they probably just tell you to go straight home. With the threat of a fine if they catch you doing it again. Guess I feel too old to stand there being made to feel like a schoolboy caught scrumping apples . . .

Have to see what I can do. Meanwhile, gratuitous garage shot:

Thanks again!

 

[Raymond]

And then my nipple fell off.

Mrs kind enough to make an online purchase so I'd have an excuse for going out on't bike.

Bike pulled out into the sunshine. No, really, nice Spring day here in Scotland. Helmet, jacket, gloves, rucksack & climb aboard. Thought to pull the clutch and give a kick to ensure plates free. Started readily - second kick I think. Warmed the engine for a couple of minutes. Pulled clutch to engage first but this time lever came right to the bar with no resistance.

Searched the ground for the nipple - for forensic purposes - and this is what I found:




Photos courtesy of Mrs' mobile phone.

Ugh. Been rather amateurishly soldered at some time. No wonder it gave up.

First point - very glad it fell apart when it did. No better place than our back yard to find meself without a clutch.

Second point - should have noticed how bad it was when I had everything dismantled. In fairness, doesn't look that bad from all sides. The lesson is, should have put me specs on and inspected every component more carefully. Instead, just glanced at the clutch cable and made a mental note to replace at some time, like once I have the bike running properly.

Oh well, the W800 had a nice run out.

Must go now, search on-line for a clutch cable . . .

 

[MaxPete]

Excuse my bluntness but,

Rasputin - it is difficult for me to imagine a Yorkshireman being "blunt"...

Raymondo - that really IS a very pretty garage - another dinner out out for Madam I say!

 

[5twins]

As you may be aware, many of us like and use the Motion Pro clutch cable (part #05-0013). It's very well made (heavy) and very reasonably priced, at least in this country anyway. Buy two so you have a spare .....

https://www.amazon.com/76-81-YAMAHA-XS650-Motion-Standard/dp/B000OO0WT6

Other Motion Pro cables you may need/want .....

Throttle - #05-0012
Tach - #05-0100
Speedo - #05-0001

 

[650trader]

90 percent of the time a popping or backfire on throttle roll off is a leak in the exhaust.
Usually the leak is at the muffler joint or the head.

 

[Raymond]

Pete, thank you, aiming at the look & feel of an old-fashioned village garage. It's getting there. Starting to put up a few 'old' metal garage signs. Have some proper old items like quart oil pourer and brass oiling cans on the shelves. Spend time in the garage so it might as well be a place I enjoy being.

Don't know when we'll be able to go out for a meal or anything much in fact. But I do cook a nice dinner for Mrs every day. Well, suppose one would need to ask her how good my cooking is . . .

5T, I've already been and bought an XS650 clutch cable from Yambits in Yorkshire. Don't know if Motion Pro is available in Britain? When I had a look at CMSNL, they have a clutch cable at E44 plus postage of probably quite a lot. From Yambits, £14 including post.

650trader, my first idea was an air leak. There's a link pipe between header and silencer (muffler) on my bike so extra opportunities for a leak. But 5T suggested taking a look at adjusting the mixture screw and that's what I'll do first - see if that cures or reduces it.

This afternoon, been having a go at fixing the pesky side-panel catch. Has been bodged by a PO with a very weak little spring from somewhere and a bit of thick wire pushed through for the catch part. Which has now bent and no longer functions. So ditched that, passed a 3 mm drill bit through the hole at the end, then snapped the bit and epoxied a short length of that for the catch instead. We'll see.

 

[member28833]

Great bike shop and hideout there!

 

[MaxPete]

There's a link pipe between header and silencer (muffler) on my bike so extra opportunities for a leak. But 5T suggested taking a look at adjusting the mixture screw and that's what I'll do first - see if that cures or reduces it.

For an exhaust leak to really affect backfiring I would expect that it would need to be right up at the joint between the cylinder head and the exhaust header pipe. Anywhere downstream of that is getting close to the end of the muffler (trans: "silencer") and that whole thing is an exhaust leak to the atmosphere.

Anyhow, there is a "crush" gasket in the joint between the cylinder head and the exhaust header pipe and if it is crushed too much, then the seal won't be good. One way to check it is to have a look right at the cylinder head - exhaust pipe clamp ring joint to determine if:

• there is a gap between the exhaust clamp ring and the boss on the cylinder head?

If there IS a gap - then you can snug the two big chrome exhaust header nuts up a little see if the leak stops. If there is NO gap, then you likely need to replace those crush gaskets.

Here is the XS650Direct / MikesXS listing for them (cost is $4.95 CAD/pair or about $0.39 cents USD):

Headpipe Exhaust Gaskets (Pk./2) - Original Yamaha Type.
OEM Ref.# 256/3GD-14613-00, 90430-38054.
Fits: All XS650's 1970-84

FWIW - I have found that backfiring can often be cleared up by simply turning the air mixture screw out a little to richen the mixture. An eighth of a turn did a fine job on Lucille the last time she was "flatulant".

 

[Raymond]

Pete, we have discussed exhaust gaskets per PM. Have turned the mix screw out from 2¼ to 2½ but have not yet been in a position to test ride . . .

Tomorrow, will adopt your suggestion and take a look at the clamp ring to head clearance. Or lack thereof.

 

[5twins]

The suggested mix screw setting (2.25 turns out in your case) is just a starting point. From there you should fine tune the setting to find where the engine idles fastest and smoothest. There will be a range of adjustment maybe 1/2 turn wide where this happens. We refer to this as the "sweet spot". Turning the screw past this range in either direction will cause the cylinder speed to slow and start stumbling. With the BS38s, I can hear the changes mix screw adjustments are having so I'm able to tune and set them by ear. It's pretty easy to do, I'll run you through the procedure .....

Start with the mix screws set to spec, start the motor and let it warm up, and make sure the idle speed is correct, no faster than the 1100-1200 RPM spec. In fact, you'll be better able to hear the changes your adjusting is having if you turn the idle speed down a bit, say to 900 or 1000 RPMs. Do one cylinder at a time so pick one to start with, doesn't matter which. Kneel next to that cylinder and give it's mix screw a quarter turn out. Wait a few seconds for it to have an effect, then give it another 1/4 turn out. Keep doing this until the speed falls off and the cylinder begins stumbling. Note how many turns that happens at. Now, set the screw back at spec and work it in in the same manner. Note where the cylinder begins to falter. What you're trying to do is find that "sweet spot" or best adjustment range. Once you do, running the screw at it's rich end (screw more open) will alleviate the decel popping the best.

 

[Raymond]

Thank you for a very clear explanation of setting the mix screw! In fact, could probably do this while waiting for the new clutch cable. Cheers, Raymond

 

[MaxPete]

Thank you for a very clear explanation of setting the mix screw! In fact, could probably do this while waiting for the new clutch cable. Cheers, Raymond

Good grief Raymond - what were you doing up at 3:55 AM?

....oh....yeah...wrong side of the road.
Got it.

 

[Raymond]

The reported times for updates make little sense to me. Given up trying to work out if one is posting from UK whether XS650.com uses Greenwich Meantime, British Summer Time, one of several US time zones or just Central Mongolian time.

Today, tried a little carburetor whispering. I wish.

Miss November started first kick. Let her warm up for a couple of minutes, till the engine would idle without me touching the throttle. For people not familiar with this XS, I don't use the 'choke' and just give a wee crack of throttle to start up.

Anyhoo, started playing with the mixture screws. At first, with the r/h carb, it seemed that the more I wound it out, the more the revs went up. Decided it was at least in part the bike warming up so used the throttle stop to bring down to about 900-1000. With a bit more playing about, concluded best tick-over was with screw between 2¼ and 3 turns out. I've left them set at 2⅜. The bike seems fairly happy to chunder away at lowish revs - maybe 800? The tacho gets a bit indecisive when the revs are that low.

But today I've left the tick-over about that 900-1000 range. See what it goes to when the engine gets proper warmed up after a run.

When the lock-down is over. No, when I have a clutch cable, I'll head out for essential supplies and see if the backfiring is still as bad. Maybe have a further play with the mixture. Also, will inspect the header clearance as Pete suggests.

BTW, the r/h side-panel clip now better than it was. Trust it more with a rigid 'catch' than a piece of wire and it fits better with a different spring in place.

 

[5twins]

Yes, check the idle speed once fully warmed up. Although these bikes can be made to idle lower, like at 800 to 1000, it's really not a good idea to run them like this. Very little, if any, charging will be happening at that speed. Another possible issue could be random stalling at stops. I know this because I tried it when I first got my 650. I thought the 1200 RPM idle speed just sounded too "busy". I was used to a lower 900 to 1000 RPM speed from my old BMWs. So, I turned the 650's idle down but then, as mentioned, when waiting at a stop light the bike would occasionally just die. It needs and likes the 1100 to 1200 RPM factory recommended idle speed. And over time, I've grown used to it. It doesn't sound too "busy" to me anymore.

 

[Raymond]

Saturday, prepared for clutch cable replacement:




Today, new clutch cable arrived. Before fitting, lubricate:




Hung from a rafter and painted with that old stand-by, Harley-Davidson SAE90 gearbox oil.

While that finds its way down the length, reading hereabouts on cable routing and the merits of straightening the angled ferrule a little.

 

[Raymond]

Part 2. Read various clutch cable threads - there is just so much information on this forum - about straightening the 'elbow' and alternatives for routing the cable.

Back in the garage found the new cable had an elbow with a little less bend. If the Yamaha originals had about 20° this has about 15° so I left it alone.

Used the old cable to try out various routes. Previously, putting the bike together, I routed the cable up outside the l/h carb, then along the head, crossed under the frame tube just ahead of the head steady, then up between the forks just right of the ignition switch and behind the switch to the lever.

Tried Gary's - similar except crosses behind the head steady and uses the tacho cable bracket to retain the cable from wandering. Tried 5T's, up between the carbs, but found the old cable was too short.

By this time, after repeated painting with oil and - ahem - working the cable outer up and down, oil was emerging at the lower end. Feels beautifully smooth.

Out of curiosity, compared the cable lengths. The new one is about 3 or 4" longer. So in the end, have routed the cable up between the carbs, along to the tacho cable bracket, etc:





The cable pull feels easier than before so I'm pleased with the job. Haven't been out for a test run yet but I started the bike and the clutch appears to work fine. Slightly difficult to select neutral so will adjust a little bit - there's probably a little bit of stretch in a new cable?

Before anybody asks, that cable tie is not holding the brake line. I use a cable tie on the fork leg to assess how much fork compression occurs because I'm thinking about fitting an SR500 top yoke - triple tree in US? But that's another story . . .

 

[member28833]

Great ideas Raymondo ! Here is a custom clutch cable routing which works with lower and narrower handlebars. example
Using a longer clutch cable opens up options of routing it in front of the gauges. Long easy radius route. And Tons of bling