Stella - 1977D survivor, back on the road.

Nope, the PO had gotten past the staked ends for me. I had to be careful with one chewed up screw, but it came out. I replaced them all with hex head stainless with blue loctite.
 
Thank you, pckopp, I've been following your work as well. Reading the various build threads here is what gave me the courage to take on this bike with the plan of 'doing it myself.'

And to the rest of you gentlemen, thank you so very much for your expertise and encouragement. I've got a ways to go yet before I'm finished, but I'm beyond excited about the progress so far and have this forum to thank for it.

This video shows Stella upon her first startup since I pulled the carbs two weeks ago. No tuning has been done beyond a bench sync using the visual 'match the light leak' method. Cam chain, valves, timing are all untouched since the teardown started. Mix screws are at the book spec position. Cleanup and tuning to follow.


On another note, I found a previous owner from before my previous owner. He runs a custom motorcycle seat company that uses aerospace foams and fabrics. He's a commercial pilot, too. Pretty nice stuff, but they don't touch old bikes anymore. Even one he has sentimental attachment towards.
 
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I'm going to reply here to the question about idle speed you asked in a different thread. I don't want to give the guy who started that thread any more advice or help, not even the time of day. He doesn't do any work on his bike, he pays other people to do it. I don't feel this site is here to advise people like that. We turn our own wrenches and enjoy doing so.

Anyway, you've been advised about the evils of idling too low (lack of charging and oil circulation) but not so much about what too high an idle speed can do. Some have told you it's fine but I don't agree with that. The big problem it can cause relates to your ignition timing. The ignition starts into it's advance curve somewhere between 1500 and 1800 RPM. As it advances, the RPMs naturally climb. That induces more advance and more RPM increase. It becomes a self-feeding problem. The RPMs can gradually build up to 2000 or 2500 RPM on their own, without you even touching the throttle.

Now that your carbs have been gone through and are closer to being properly jetted, you found you can set the idle to spec. Almost anyone can get a bike to run hard and fast, WFO as they say. It takes a bit more finesse to get they running well "low and slow", to get a good dependable idle and smooth low speed running. Yes, I think that is a good indication of a good state of tune. Now that your carbs are better, you may be able to reap the benefits of having the timing slightly retarded. In your hot location, the protection against pinging is reason enough to try it. Mine would only ping on really hot days but I'm in the N.E. My "really hot days" are like your "every day", lol.
 
Thank you 5T.

I do have my timing retarded just a bit as you suggested. Checking it last night, I found my bike no longer does the center stand dance as the RPMs raise past 3500. That now starts north of 5000.

I've been riding it the last few days and am very pleased with where it's at. Running very smooth up past 6000.

Take off still feels strong enough with my 18/34. Faster than the cagers around me at least. If anything, the new throttle/clutch transition is easier for me to take off smoothly.

I do find that she really wants 4000 as a minimum cruising RPM. 3800 is still ok, but 3500 bogs. Before the carb rebuild and sprocket change, 3500 was fine.

But, with her smoothing out, 4200-4500 makes for very nice cruising.

As for continued tuning, I'm on hold until I find a proper sized clamp for the manifolds. The ones that are on it bottom out before they're snug. I have a suspicion that may be causing some decel popping. An extra 1/2 turn out on the mix screws helps, but I know those intakes need to be tightened before continuing.
 
FWIW, I feel for all y'all putting your bikes in storage for the next few months. I ride all year, but comfortable riding is just beginning.
 
Two tips I've found very helpful:

A bit of fuel line on the idle speed screw for easy on the go adjustment.

Tapping, not pushing, to find neutral.
 
5twins said:
I'm going to reply here to the question about idle speed you asked in a different thread. I don't want to give the guy who started that thread any more advice or help, not even the time of day. He doesn't do any work on his bike, he pays other people to do it. I don't feel this site is here to advise people like that. We turn our own wrenches and enjoy doing so.

Anyway, you've been advised about the evils of idling too low (lack of charging and oil circulation) but not so much about what too high an idle speed can do. Some have told you it's fine but I don't agree with that. The big problem it can cause relates to your ignition timing. The ignition starts into it's advance curve somewhere between 1500 and 1800 RPM. As it advances, the RPMs naturally climb. That induces more advance and more RPM increase. It becomes a self-feeding problem. The RPMs can gradually build up to 2000 or 2500 RPM on their own, without you even touching the throttle.

Now that your carbs have been gone through and are closer to being properly jetted, you found you can set the idle to spec. Almost anyone can get a bike to run hard and fast, WFO as they say. It takes a bit more finesse to get they running well "low and slow", to get a good dependable idle and smooth low speed running. Yes, I think that is a good indication of a good state of tune. Now that your carbs are better, you may be able to reap the benefits of having the timing slightly retarded. In your hot location, the protection against pinging is reason enough to try it. Mine would only ping on really hot days but I'm in the N.E. My "really hot days" are like your "every day", lol.
Click to expand...

5twins, you bring up a good point. However, if someone chooses to idle at 1500 rpm, it's likely because they have other problems such as air leakage around the carbs/manifolds area, an ATU that has worn out parts, and/or worn out needle jet O rings on the BS38 carbs, so they end up with a hovering high idle. They may also have the mixture and/or initial timing adjusted wrong.

Anyone that asks "Is it OK to have the idle at 1500 rpm" , indicates that they don't understand how to tune and/or troubleshoot these engines.
 
Clarification, please:

So, RG, you agree with 5T that 1500 is not ok, and an owner should attempt to correct it so that a steady 1200rpm/13v idle is possible?

That is, 1500 is not just a personal choice and when needed, is an indication of improper settings or undue wear?

I'm not sure how your last posting differs significantly from 5Twins' post. It does, however, seem to differ from your post on the original thread.

And please, gentlemen, when on this thread let's keep discussion to the issue at hand, and refrain from comments about another OP.

This is very interesting stuff, to me at least. I, for one, don't fully understand how to tune and/or troubleshoot these engines.
 
Another by product of a high idle, that hasn't been mentioned, is the damage to the clutch basket springs. These are a problem at the best of times but if your going to be riding around town a lot and in and out of neutral, having an idle in the 1500 mark is just going to kill the basket.
 
There are 6 cush springs an the back of the clutch basket, These are dampeners. A lot of other bikes have a rubber dampener behind the rear sprocket.

The original cush springs are considered a bit soft and are known to brake. Mikes XS sells a kit and here in Aus our resident club racing expert sells a set of stronger cush springs.

Here's a link to an article on our club site. http://www.xs650.org.au/Technical Info/clutch.htm.

If you want to go one further and convert the rear hub to a cush drive http://www.xs650.org.au/Technical Info/hub conversion.htm
 
Thank you. My clutch is working well for me, so it's down the list, but I'll be sure to check those resources when the time comes.

My question is more about how a high idle can harm those springs, but I'll do my own digging first. I'm sure once I understand the system it'll be apparent.

But now that I think on it a little, it might make some sense that a lower idle would reduce the engine/wheel speed differential making it easier on the clutch. However, I usually give just a bit of throttle before letting off the clutch, which in effect might be the same as a too high idle. I've done this with all manual trans vehicles.
 
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DanielBlack said:
Clarification, please:

So, RG, you agree with 5T that 1500 is not ok, and an owner should attempt to correct it so that a steady 1200rpm/13v idle is possible?

That is, 1500 is not just a personal choice and when needed, is an indication of improper settings or undue wear?

I'm not sure how your last posting differs significantly from 5Twins' post. It does, however, seem to differ from your post on the original thread.

And please, gentlemen, when on this thread let's keep discussion to the issue at hand, and refrain from comments about another OP.

This is very interesting stuff, to me at least. I, for one, don't fully understand how to tune and/or troubleshoot these engines.
Click to expand...
Daniel......................I think you are misunderstanding some of my statements. The original thread poster, asked if it was OK to idle at 1500 RPM. I said it was fine to idle at 1500 rpm if that is his choice. I said my choice is to idle at 1100 to 1200 rpm. I looked at the question as a straight question...................can he do it or not do it. I stand by what I said...................yes he can choose to do that.

There are two possible cases. Someone has a bike that is perfectly in tune, and having no worn parts in their engine. If they choose to use 1500 rpm at idle, that is a personal choice......................maybe they like the sound of the engine or exhaust at that rpm or maybe they own shares in an oil company . I doubt many people would choose to do this.

In a second case, if the engine is out of tune, and has worn parts as well, then perhaps the engine will not idle below 1500 rpm. The person has no choice as they don't have the knowledge or ability to correct the problem. To me, that means there are several things wrong that should be corrected to bring idle down to 1200 rpm.

On this web site we get many questions that do not have just one answer.
As an example: If someone posts that they want to use 10W30 oil in their XS650, is that OK to use it. I might say you can use it, if that is your choice, but I prefer to use 20W50 in my engine. Differing subjective choices..........................both will work, but one choice may lead to a noisy engine and extra wear on engine parts.

Just my way of looking at things:bike:
 

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