Usually, with everything set right, these are easy starting machines. And they usually kick start just as easy, if not easier, than electric start. On the one hard starter I worked on, the issue turned out to be improperly set float heights. The fuel levels in the bowls were too low which I'm guessing was starving the bike for fuel, especially when a richer mix was most needed (during start up). So, when you install the new float needles and seats, do carefully check the float levels to insure they're correct. This is what I found on that hard starter, much too low .....
-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
Carb slides slightly askew
- Thread starter Marlin72xs
- Start date
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
Oh, yes. Exactly, when things are right, the XS is one of the easiest kick starting bikes. There were times when I hardly pushed down and it would start. In 76, when i acquired her, I only kicked it and used the starter only when stalling at lights. A year later it stopped working, so kicking was the only way. Never worried about it not starting. Even with low compression, I never had a problem.
Well, carbs are off and in the basement. Putting the new float needle assemblies in tomorrow. Can't wait.
Well, carbs are off and in the basement. Putting the new float needle assemblies in tomorrow. Can't wait.
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
Hey 5Twins, just received the oem cam seals fro Partzilla. No wonder my cam seals leak. I'm guessing you have tjis pict already.
Well no, but I am aware of the different seal thicknesses. The first seals used by Yamaha were the thinnest @ 5mm thick. They changed to 6mm thick seals for quite some time but have now gone back to those original 5mm thick ones. The thing is, in this application, you don't want a thick seal. The cam doesn't stick out much on each end. Too thick of a seal won't sit on the cam end enough to seal very well. Mike's sells 7mm thick seals and most report they don't work very well at all.
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
New float needle assemblies are in. Went for a ride today for about an hour. Left the house, it was 40 degrees. Came home and it was 31 degrees. My knees were freezing.
Anyway, it ran like crap at first. Let it warm up and stopped in a parking lot to attempt to fine tune the air mix. 1/2 a turn seemed OK, but there was some backfiring again. Made some cable adjustments on the fly and it went smoother. It idled around 1200, but hesitated on blips, messed with the mix and finally settled on 5/8ths, It blipped better, so I headed home, then it would slowly die when I came to a stop. Had to work the throttle at every light. I hate that. Oh, at a constant 70, it would hesitate in short negative blips every 10 or 20 seconds.
Just a note: Installed the new float stuff and I had to readjust the levels. They were way off with the new needles.
I haven't spent enough time with it; it was too cold. I'll do the dead cylinder adjustment when it's a little warmer. Then I will recheck the float levels and maybe put the original pilot jets back in.
Anyway, it ran like crap at first. Let it warm up and stopped in a parking lot to attempt to fine tune the air mix. 1/2 a turn seemed OK, but there was some backfiring again. Made some cable adjustments on the fly and it went smoother. It idled around 1200, but hesitated on blips, messed with the mix and finally settled on 5/8ths, It blipped better, so I headed home, then it would slowly die when I came to a stop. Had to work the throttle at every light. I hate that. Oh, at a constant 70, it would hesitate in short negative blips every 10 or 20 seconds.
Just a note: Installed the new float stuff and I had to readjust the levels. They were way off with the new needles.
I haven't spent enough time with it; it was too cold. I'll do the dead cylinder adjustment when it's a little warmer. Then I will recheck the float levels and maybe put the original pilot jets back in.
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
I complain about a mere 31°F. And then there's gggGary at arctic temperatures. Hope you're staying warm! You too, Superjet!
Last edited:
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
So, I have 2 spares from the 75 and guess what. Yup, 1 of them also leaks. My carbs were relatively clean while sitting for 23 years, but the 75 bowls were filled with burnt molasses.
Ok, couldn't initially kick start it, but went out for a ride with my little screw driver. Only made adjustments whilst being stopped on top of a big hill. Went over Blood Mountain and back, about 100 miles. It idled fine, ran smooth, throttle blips were crisp, but still doesn't kick start all the time.
Perhaps I'm not measuring the floats heights properly, eh?
Perhaps, but with the BS38s, it's pretty easy to measure them because there's no jet block or tower between the two float "bulbs". You place your steel rule on the far side and sight evenly over the tops of the "bulbs". These are '77 floats set at 25mm but I think your earlier carbs spec 24mm .....
Measure from both sides to detect any twists in the pivot bracket. It's not uncommon to find that.
Measure from both sides to detect any twists in the pivot bracket. It's not uncommon to find that.
I reckon you've seen this before.
Ggggary's recommendation. Post #84.
http://www.xs650.com/threads/cruzinimage-bs38-carburetor-floats-review.51657/page-5#post-546371
Ggggary's recommendation. Post #84.
http://www.xs650.com/threads/cruzinimage-bs38-carburetor-floats-review.51657/page-5#post-546371
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
What do you guys use to rig up the external clear float level tube?
Marlin, I made my M8x1.0 threaded drainplug adapters.
Do a search on "clear tube" posted by "5twins". I recall he found an eBay vendor who offers these adapters...
Do a search on "clear tube" posted by "5twins". I recall he found an eBay vendor who offers these adapters...
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
Gracias, amigo! I like. Very Interesting. I'll check eBay, but I will also stop at my Ace Hardware store. Ace has a large assortment of screws, nuts, adapters, metric, chrome, stainless, etc. Thanks!
The Ace out here didn't have any M8x1.0 fine pitch, but I found some in steel at Napa. An alternative would be to get 2 drainplugs from MikesXS (they're plated brass), drill out, and solder some brass tubing...
Yes, I got this one from eBay. It is very nicely made and works well. I highly recommend it. In fact, I bought 2 so I could check both carbs at once, but I seldom do that .....
https://www.ebay.com/itm/Carb-Float...h=item3f96058420:g:-AwAAOxyeR9TKGci:rk:6:pf:0
https://www.ebay.com/itm/Carb-Float...h=item3f96058420:g:-AwAAOxyeR9TKGci:rk:6:pf:0
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
OK, I made one from a drain from my 75. Ain't building that one very soon anyway. Here's the pics from today. Does these look close?
Looks good from way over here...
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
Yes, it's just like that.
OK, well properly set the level usually reads a little higher like so .....
You must make sure the bike is sitting level when you take this reading or it will be off. If a re-check with the bike level confirms your reading then you could tweak the float setting a little. Low fuel levels in the carbs can cause difficult starting.
You must make sure the bike is sitting level when you take this reading or it will be off. If a re-check with the bike level confirms your reading then you could tweak the float setting a little. Low fuel levels in the carbs can cause difficult starting.
- Messages
- 683
- Reaction score
- 1,477
- Points
- 143
Sorry, for the slow response time. Yes, all was level. Had a Home inspection today and they needed the report tonight. Very interesting that 2mm could make such a difference. I mean, with all that splashing around in there and all the vibrations, there must be all sorts of standing waves in there. Well, I guess AVERAGE depth means something here. When I got back today, I had to start it to use as a comparison before I reset the float levels again. Guess what, after about 5 kicks to free up the clutch, it started in 1. I know, probably a fluke, but I will re-adjust in a few days. Thanks again, as always. If you come to this year's Rally, I'm buying. That goes for you, too, Steve. Loaded Land Sharks!
