Why do xs's miss at low speed?

[xjwmx]

Why do they all miss while idling? You can hear the unevenness.

Not to single this bike out - they all sound the same.

 

[jay760]

I think they build it in so you can constantly play with the carbs and ignition trying to get a descent tickover

 

[xjwmx]

On the bike in the video, the engine is newly rebuilt, and I'm sure the carbs are spotless and the ignition is flawless, all done by somebody who knows what's what, but yet there's the trademark
bang bang....bang..bang....bang........bang.

 

[XSJoel]

That bike needs a rephase anyway.

 

[xjwmx]

Not even any shots in the dark?

 

[Classic]

I've never ridden or seen an XS in person that had a rough idle.

Here's mine.

 

[angus67]

lolooll thats my bike! that has 1.5 over pistons, new rings, valves , johns needles, cleaned carbs to death.
I had just gotten it running that day, with my dad filming. I think that was like the third time i had ever started it.
Its an 80 with the electronic ign, and it is tuned better now, but it still hiccups everynowand then. not worried though, purrs like a kitten off idle. you'd think with a electric ticker, it would idle perfect, and only the points would do that, but, no, its prolly the cursed carbs.
heres my biuld thread if you care to look.
http://www.xs650.com/forum/showthread.php?t=183

 

[Tech7]

I would have to say it's fuel. Carbs aren't exactly perfect by design. Could be the mix gets a little lean at times at idle and causes a misfire. After all, you're just relying on engine vacuum to draw the fuel in. One miss, vacuum gets even more distorted, snowballs. It's not like EFI, where you can perfectly control fuel flow. Just a shot in the dark.

 

[TeeCat]

I'd have to agree with Tech. My bike's a single-carb with unequal runner lengths, and it's even more pronounced; idles real "cammy" like a dragbike. Then it smooths right out with a touch of throttle.

TC

 

[gaps]

crank volume and click on both videos...now sit back, relax and enjoy the music

 

[uknowme2goog]

your bike sounds good to me....i adjusted my carbs a few times and the more i play with them...the worse it sounds and the more i get pissed off...the best sound was after i syc the carbs....once adjusted let the carb be left alone...these bikes 30 years old..

 

[MB-Ian]

This is as good as I can get my idle using VM34s, I think the pilots might be a bit small though... if I adjust my idle speed up to 1400rpm its smooth with no misfires... and boring.. rather the odd miss at idle now I've owned the bike for a few months.

I.

 

[xjwmx]

I'm starting to imagine I can tell the difference between TCI and not, from their sound.

 

[Jack]

This is as good as I can get my idle using VM34s, I think the pilots might be a bit small though... if I adjust my idle speed up to 1400rpm its smooth with no misfires... and boring.. rather the odd miss at idle now I've owned the bike for a few months.

I.

Your engine sounds normal and sweet, you have no miss fires Don't forget it's firing on 360 and cam timing comes into the factor also as does type of ignition.

 

[royxxx]

they sound like proper motorbikes to me.

 

[Classic]

I'm starting to imagine I can tell the difference between TCI and not, from their sound.

My bike is points with a shot advance unit. It has UNI pods, NGK plug caps, and Vance and Hines mufflers on '72 head pipes. Stock jets in BS38's and 26,000mi on the engine.
Here's a much better video of my motorcycle's engine.

 

[cros36]

i still need to sync the carbs and put a timing light to it. the right side bangs a little off i think

 

[jchrisk1]

^ Wolverines Twin Funnel Tank. Very original.

 

[littlebill31]

Here's mine.....

 

[dguthrie]

You have deleted the stock air cleaner and mufflers, both of which have increased air flow. I bet it gets hot as hell after running a while. You're lean. Re-jet those carbs with larger jets from Mike's XS. They're really cheap. You don't need a re-phase. After re-doing the jets, the carbs will have to be balanced. You'll have more power, smoother idle, and a cooler more complete burn. Also, your engine might not burn a hole in the pistons. Hope this helps. I'm not a mechanic. I just stayed at a Holiday Inn Express one night.