My 'ordeal' this weekend

pristic

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Ok,

So first time I got her put on a long ride. A mate called me to help out at his shop 50kms away.
Just finished the bike up and down street was good

First, I thought "my rear brake isn't actually working) so I tightened up the adjuster, testing in the spot and it felt great.
Next I ride off on my trip.
I slow at the end of the street and go 'ill try my rear'
Brake then BANG. Wtf was that!!!!!
Look down, kill the engine. My rear brake stay is dangling and the adjuster/brake rod is also hanging on and bent almost 90deg!!!
The cast alloy (?) drum is missing a chunk where the stay/brace goes (from drum to frame)
Holy cow!

Ok ride back home slowly (100meters) and think hmmm, she'll be right. Unbolt it all and off I go on my way again (no rear brake - just front)
Ride the distance, all good. Smiling and enjoying riding her properly for the first time.
Help my mate out (all day) he has some customers with show cars and we park them at the front of the shop and my bike beside them.
I kid you not, soooo many people came in asking about the bike! Was an AWESOME feeling.
Anyway, late late afternoon I go to kick her and nothing. No power in my battery :-(
All good, ill jump start. Kick her over and off I go.

Ahhhh, no I don't, 100meters down the road she starts coughing and spluttering and stalling on me. No load, she revs fine, starts up first kick no problem and idles fine, rev - fine. Go again and she is missing and breaking up real bad.
Ok, call my mate "I'm coming back, bikes having a spaz"
Get there, look, test, play. Now it's late that night and my wife wants to bash me hahahah.
"Take one of the cars home and ill see ya in the morning bro" he says - oh, so cool!
"Thanks bro"
I grab the keys to the C2 Porsche with the twin turbo 350 Chev in the back!
"Ah, not that one man"
"Oh ok" I tried :)
Take the 5.4litre worked V8 and off I go.
Hmmm, feels a bit sluggish. Nail it, light up the rear and shit myself from the power. Ok, control the right foot Pete!!

Anyway, get back this morning, keen to get the bike going. All things head to the battery so I bring a spare and replace it, clean up, wire etc. kick it, fires up and revs nice. Running rich though (like yesterday)
Take her up the street and its the same problem. Breaking up under load. Test everything I can. Nothing works. 2 hours of tuning and nothing is helping.
My mate comes home (he was out when I got there) and says, check the Plugs. I say I have all good.
Pull th anyway, black as night fouled. Dry not wet but sooty and covered. $**%% me.
Ok, replace them with BP6ES (open pies, etc) and go again (he retuned her a bit and did the timing a bit - man I hate points)
Up the street I almost fall off. Pulls harder than ever and goes great. Woooohooo.

Amazing, no air filters, open pies and what I understand stock BS34 carbs and jets etc and she is fouling stock plugs to the point that they are breaking up.
I'll put in elec ignition ASAP but I find it very odd.
Air leaks would mean lean, no filters usually mean lean, open pipes usually lean. Everything points to lean yet this thing is rich as????
I'm going to pull the jets and find out what they are but any advice would help. I also will go through testing ignition components to see for issues. Weak spark or fuel would cause this I guess (could be timing etc causing it)

Having said all of this though. You can't wipe the smile off my face. Awesome weekend playing with the bike and going riding. Perfect weather too. So happy days!!!!

Cheers,
Peter

Posted via Mobile
 
Make sure the battery is charging. If your charging rotor is shorted, battery current is going straight to ground. Under that condition, your ignition will not work properly. Give it a good look before you mess with the fuel system.
 
Hey Pete, nice adventure, I was grinning too!

Revs fine noload, sputters under load sounds like very weak spark, can't arc when compression pressures go up. Roadside fix is to reduce plug gap. Sorry to hear about brakestay, been there, helpless feeling. You ever heard the expression "white knuckles"?
 
Took a pic of the drum.
The stud that the actuator goes onto snapped off too.

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And the Porsche I tried to borrow.
Hahaha

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Cheers,
Peter.

Posted via Mobile
 
Wow, welding... Some of those ancient castings don't take to welding well. During that timeframe many aluminum castings had hi silica content to improve pour/flow, not reliably weldable. If you have a knowledgeable/experienced welder in the area, you could ask him. But advise that torque on that backplate can be up to 500 ft-lbs, which will be 1000 lbs on that torque arm. Add in 100% safety factor, then you're up to 2000 lbs. Since it's trash now, what have you got to lose? Could try welding, might get lucky. But rather than just building up the busted side, I'd make a separate boss, cut a mating notch in the backing plate, weld the two together, larger weld area...
 
Agree; get it charging correctly, spark timed at idle AND 3000K checked on both sides, then if it still shows rich...

At the risk of sounding like a broken record (OK I DO sound like a broken record) #1 cause of too rich BS34's is bad O rings on the float valve body.

AS568-010 fit well, a smidge of lube helps them slide into place.
 
Ok the wife isn't letting me play much so don't have time to check the o-rings however I just pulled the plugs and they look perfect. Not sooty, honey brown, nice mix.
Oh and I have a workshop lambda meter but it won't slide in due to my baffles lol. I might check the mix with that after I pull the baffles.
What should the right mix (A/F ratio) be?
Another question, when riding I don't sit up high in the rev range. I'm putting it along cause it rides nice and sounds awesome.
Are they meant to be putted along? I wind her out now and then but generally not trashing/revving. Could that have any effect?

Cheers,
Peter.

Posted via Mobile
 
Boy, I wish I was there with a large chalkboard.

A/F ideal ratio is called stoichometric, 14.7:1 by weight. Remember your chemistry class, balanced equations? Older internal combustion engines need to be richer than that to be tolerable.

Over-revving vs lugging. These engines were designed for the higher rpm, like 4000rpm @ 100kph. There's an interesting dynamic that occurs in rectilinear motion, as applied to con-rod engines, in that rod big-end loads peak at certain zones on the crankpin when below 2700 rpm (lugging), occur at different zones above 3000 rpm (ideal for this engine), and are somewhat indeterminate in that "detonation prone zone", 2700-3000 rpm. If you're not using much throttle, any rpm is fine, as long as the spark advancer is good. But if using significant throttle, best be above 3000 rpm.

I know what you mean, I love meandering the backroads in 5th @ 45 mph (75 kph). AND, I find myself looking for that elusive 6th gear...
 
Yep I know all about A/F ratios and stoich but wasn't sure on any "best performance A/F" for the XS ;-)
I totally agree! I sit there looking for 6th gear too hahaha.
Ill pish it up a little from now and see how I feel.

Cheers,
Pete

Posted via Mobile
 
The "cush drive" springs in the back of the clutch housing aren't very robust lugging may be extra hard on them. I shouldn't but love to lug my 1100 Shadow which will pull nicely from about 900 RPM. That motor has a nice big roller ramp cush drive.
 
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