Compresion Release

[Steveair2]

Hey group, I just bought a couple of XS650's. One is a 72 with a compression release.
I want to use a Pamco ignition, and kick start only. Do I need the compression release?
Thanks in advance.

 

[jetero41]

INXS has a great thread "starter and decompressor" check it out.

....and then send me the parts....

the answer in the simplest is no, not with kick only

 

[Steveair2]

Can't find the thread INXS has yet.

 

[jetero41]

in the "tech" section "xs650 electric start system, Starter", i believe never did learn how to post links.

 

[Steveair2]

OK, I read the "XS650 electric start system, starter" thread. Wondering why I did it.
I just want to have kick start only and am wanting to know what to do with the compression release.

 

[Patches]

These bikes really aren't that hard to kick. Now my 95" shovel head, that's a different story.....

Anyway, IMHO there is no need to have the compression release for kick only, unless you are built like a 12yr old school girl. Not saying that you are....

You can do nothing with the compression release or take it off and replace it with a later year square tappet cover that doesn't have provisions for the compression release.

The whole reason Yamaha has the one square tappet cover is because of the compression release that they introduced early on after the XS1. Later they found that they didn't need it with the newer starters but never changed the design back to 4 triangular tappet covers (XS1 style) and just left the one square. You will find that later bikes then yours have one square cover but with no compression release.

Kind of a long winded answer I realize, but I hope it helps. Good luck with the project.

 

[jetero41]

Recommended that thread as I think INXS did a great job of explaining the decompressor allowing you to make an informed decision.

 

[Steveair2]

Thanks Patches! I like long winded answers.
Thanks for your help as well jetero41.
Now, if I could just decide on a frame configuration.

 

[gggGary]

The compression release adds that old timey look to the bike if that flips your switch.

 

[dwyatt]

I'm running kick only with 11:1 compression ratio. Just cowboy up and kick her.

 

[jetero41]

....and send me the parts......,

 

[Steveair2]

Ok, I just went out and took a good look at the decomppresion linkage. I never noticed the small lever under the front brake lever until just now. I do plan on kick start only.
Jetero41 gets first dibs on the parts. It will take me a while to get them off. I have been working sixty to seventy hours a week, not much time for anything else.

 

[jetero41]

and enjoy the bikes

 

[XSLeo]

I think I'd keep it. Just to make people ask "whats that?"
On my 750 kitted 75 It helps out on cold starts where it can take a few priming kicks before you try starting. Your foot can start to hurt and the battery don't like the cold starts either.
Leo

 

[hedjhawg]

Can anyone confirm (or refute) that the early (72-and earlier, 22mm wrist pin) had the same compression ratio as the later motors?

My understanding is that even though the early (256) pistons and rods were different than the later (447) ones, but the swept volume and compression ratio has always been the same...

 

[TeeCat]

I can't confirm it, but I was under the impression (from something I'd read somewhere) that the earlier motors had slightly higher compression.

TC

 

[Brian902]

Jetro41,

Forum 101 - adding links;

Like;

http://www.xs650.com/forum/showthread.php?t=143

Here's how;

Highlight the link at the top left of the page by clicking on it, when it changes color press the CTRL key and then the C key (copies what is highlighted), then click back in the message where you want to paste what you just copied, then click CTRL key and the V key to paste. Easy once you do it a couple of times. And very handy. Work almost everywhere too.

 

[XSLeo]

In my factory manual for the 70-74 years the compression ratio was 8.7:1 on the XS1. During the run of XS1B's at engine number 23129 they lowered it to 8.4:1.
They did this by shaving off the top of the piston.
I recall reading the reason was to lessen the vibration.
Leo

 

[650Skull]

Bulliton release 10/18/71

 

[gggGary]

Thanks for that 650 skull it's filed in my hard drive.