Finally got my vision running, but not well... ?these carbs need some serious tuning. ?It runs ok at idle (half choked) and above 6000 rpm, but inbetween is trouble. ?I really have to coax it up to speed or it will just bog and stall when I open it up. ?I figure the main jets are doing their job (over 6000rpm it runs well), but perhaps the pilot jet is responsible for that lower rpm lagging??
I am in Colorado at 5000 ft. and was hoping someone might know the correct settings for this altitude. ?Jet sizes...etc. ?Ballpark even?
Haven't bought manual yet so I'm at a loss. ?
Of the two screw adjustments on the carbs (one screw near the bottom and another halfway up)... can anyone tell me what is what? ?These carbs don't exactly lend themselves to a backyard mechanic. ?
Thanks!
H2o lawyer may be able to give you jet sugestions, he's in mile high country too, you really need a manual . Lucky sell a CD version for little money.
Hi Jon -
Where abouts are you located? Be nice to get a High Country Vision ride going! If you're not too far from the Fort Collins area, I'd be happy to get together and help you sort it out.
As for the jets - I'll need to take a look at mine to be sure. I didn't write them down on my last carb rebuild ::) so it'll take some doing to get at them.
Mine's running great now. I know my dealer in Steamboat Springs did the airbox mod and he said they really spent time on the carbs before they sold it to me. Didn't help much - still suffered from major stumble even the day I bought it. Just learned to be gentle with the throttle.
What carb balancing equipment is recommended for the Visions and how often should it be done?
I've got a set of dial gauges but they don't work well.
Regards
Glyn
Hi Glyn -
You can make a carb balancer (manometer) with some clear plastic tubing, a yardstick, some tape, wire ties and ATF. Plans for one can be found on Lucky's site in the artwork section. ( //www.xz550.com/art.html ) Look in the third row from the top, far right side.
I spent about $5.00 US for mine and it works great.
H2o
H20
Thanks for the offer. I'm in Boulder, so your tuning specs would be spot on! If you get a chance to check them out I would be very grateful. Can't wait to get her going well!
If you could tell me your main jet size and perhaps where you've got the other screws positioned, I would love it.
Free tip: The Yamaha dealer in Boulder is a bunch of monkeys.
Thanks
Jon
Jon -
You're just down the road a ways. Sounds like your Yamaha dealer is like mine. When I went in for a side cover gasket this spring, the parts guy started looking for XZ550 under Suzuki! He seemed quite surprised when I told him it is a Yamaha. The guys that worked there last summer knew what I was talking about by vague description when I'd forget to look up the part # before I went in. Good help is hard to find.
I can't get to my carbs until Monday but I'll see what jet sizes I can locate then. I do know that setting both mixture screws at about 4.5 turns open from lightly seated got mine real close. They're within 1/2 turn of that now. I've got an extra set of carbs - Thanks Kiawrench! - and will also check them to see if the jetting is the same as mine.
H2o
Jon -
My carbs have 135's for both pilot air jets (the ones on the carb tops). ?Factory manual says 130's for the pilot air jets. ?My front main jet is 122.5 and the rear main is 127.5. ?(behind the 10mm brass plugs) ?If these don't help, I could remove the carbs to get to the pilot jets at the bottom of the carb bodies but that would require a resynch when I reinstall them. ?The factory manual says #60 for the pilots though. ?I'd be happy to do it if you really need the specs but don't want to go to the trouble if you don't need those particular #s..
I'll post what all the jet sizes are on my second set of carbs later today. ?Those came from the southeastern part of the US so they might be different.
Hope this helps.
H2o
Just got out the second set of carbs. ?Somebody really messed with them! ?Found a 120 and 130 in the pilot air jets and a 130 in one main. ?Couldn't remove the other main - the amount of gunk in them is amazing! ?Couldn't get light to the jet to even see it. ?Rust & fuel evap varnish abound. ?Going to let them soak in rubber friendly solvent for a while. ?At least I know I now have a set for some parts. ?Haven't taken them apart to check the floats yet but I am anticipating a major dredging operation in the bowls.
Just one quick thought - do you have the vacuum flapper mod in the airbox? Early '82s did not have the vacuum operated flapper and it was a dealer retrofit.
H2O,
there is no reason to re-synq the carbs if your only pulling ot the pilots underneath the carbs. only if you loosen the braces that hold the 2 carbs together.
--Lucky
Jon
From your first post it sounds like your idle circuits are not clear. Have you cleaned your carbs? if not do so or send them to Lucky or one of the other guys providing the cleaning service. Make sure the off idle holes, above the throttle plate, are clear.
Thanks Lucky -
I was under the impression that when the carbs were removed, they could lose their synch. somewhat. I decided to check the synch again anyway this evening (went for a ride this afternoon - power seems a little down from last year and exhaust tone is different) so I'll get to those pilot jets then to see if they're different than the No. 60s that were factory installed. Just need to let things cool down a bit before I pull the carbs. I believe I remember my dealer saying that the only jets they changed for high altitude were the pilot air jets so I'm assuming that I've still got the 60s for the pilots.
I've synqed them with a vacuum guage manifold , a mercury manometer and a home mand manometer that uses ATF. all work ok, but you need to make repeated adjustment and tap the guages after each adjustmant on the vacuum guages to get a close synq, on the mercury and atf type , don't run it above 2500 rpm or you will suck the mercury or atf right out of the guage!
Thanks H20. ?That really helps me out. ?As soon as I get a chance I'll have her tuned up and let you know how it works out. ?Thanks again. ?We should go for a ride when my bike is ready.
And yes, I do have the vacuum flapper mod.
My pilot jets are 60s. ?I have all sizes for high altitude setup written down and now posted.
front main - 122.5
rear main - 127.5
pilot jets - No. 60 (both)
pilot air jets - 135 (both)
All are as stock except the pilot air jets - the factory setup for lower altitudes is 130. ?Now, if I could get her running as well as she was before I did the carb R&R. ?Oh well, I've got some time to get things right - its not far off.
When I synched mine the first time last summer, I got the homemade ATF manometer hooked up, and proceeded to fog the whole neighborhood with burning ATF ?::) when it all got sucked into one carb - they were really out of synch! ?I didn't have the problem @higher RPMS after they were set close. ?Even ran it @ 5,000 to check them and one side did rise a bit but not even close to getting to the carbs.
Jon - I was thinking the same thing - maybe a trip to Estes Park and over Trail Ridge to Grand Lake for lunch. One of my favorite rides. The Peak to Peak Hwy between Boulder & Estes is tons of fun.
H2o
Sounds like a blast, H20. I'm afraid it'll be a while before my bike is road worthy, but hopefully not too long!
Guys, I'm riding in Bozeman, MT and have been doing a lot of tinkering w/ carbs to get them tuned for altitude. We're at around 5000ft. I'm actually running a bit leaner than H2O. I've tried his setup -135s in each pilot air jet and 122.5 front main,127.5 rear main. It seems to still run a bit rich. I was experiencing a subtle hesitation throughout all revs. I leaned things down by keeping 135 pilots and going with 120 front main and 122.5 rear main. It seems to be about as good as it's going to get. No stumble or hesistation at all. I think for my bike at this elevation it is the ideal setup. You might give it a try. I agree that the problems you described are more related to blockages in the pilon circuit - probably in the group of tiny ports that enter the main ventury right at the butterfly flapper. Mine were clogged at one time and required the choke to keep her running. The choke basically bypasses these tiny passages and dumps fuel right into the intake below the flapper. Anyhow let me know how it turns out for you.
I had the exact same problem as Henri with having to keep the choke on to keep it running. I cleand those very passages (plus the one jet I missed) and she runs great. Pay close attention to those passages and I recommend using the carb tool you can get from yamaha (i used a welder tip cleaner from any parts store which is basically the same thing).
Ken
Thanks for the input, Henri.
Might go get myself a 120 jet and do some jet swappin' and experimenting in the next few days.
H2o
Today, I tried the 120 front - 122.5 rear jetting Henri is using in Bozeman, Montana. The elevation there is almost the same as here, (60 miles north of Denver, CO) at about 5,000 ft.
After I made the jet swap, I found I had a very flat spot in acceleration from 4,500 to 5,000 RPM. ??? Not the stumble I've had and eliminated in the past but just a very noticeable drop off in performance right at 4,500, and coming back @ 5,000. I was not experiencing it at all before the jet swap. Maybe something dislodged and clogged elsewhere in the carb but unlikely as I had the carbs out, did a minor clean & blew out all the passages w/ compressed air & checked synch on Thursday. Ran good Thursday, Friday and today before the swap.
Played around with the f & r mixture screws and got them as close to correct as possible. The flat spot remained and is very consistent. It does not matter whether I'm using lots of throttle, lightly rolling it on or anything in between. No stumble off idle and great power to 4,500 and from 5,000 to redline. Maybe a little stronger in the 6,000 - 9,000 meat of the powerband than with the larger jets but difficult to tell for sure.
I happened to have the 120 sitting around so that was a no cost test. I need to go get myself a 125 to try in the rear. If the flat spot doesn't go away, I'll probably go back to the factory 122.5 / 127.5 setup.
This is not really a question, but more of an observation and possible point for discussion. It was running very well before I decided to try the jet changes. I know it runs well on the factory jetting (with 135s for the pilot air jets) but was just curious if I could pull a little more power out of it up here. I had it running a little better last summer & fall (lifted front tire 1st to 2nd and got very light in front 2nd to 3rd) 8) and with a little more futzing with it, will be running quite smoothly once again.
The bike shops will be closed here Sunday and Monday as usual so I won't be able to get the 125 to try until Tuesday. The 2 size drop in the rear may be just a bit too much for mine. Will keep y'all updated.
I think this is a question on the basic side but here goes. When doing a carb setup where are the adjustments that I should be concerned with. I have found the mixture screw at the bottom of the carb right before it goes into the manifold and I know of the synching rod that can also be adjusted. Are there others that I am not aware that need to also be adjusted?
Kevin
Still workin at it.
The adjusters you have found are the only ones I've dealt with. Beyond those adjustments is the jetting that I'm experimenting with now. Lucky and Rick_G may know of additional adjustments but I can't think of any at the moment.
Mine seems very sensitive to mixture balance between front & rear carbs for smooth off idle performance. That's where I tend to spend most of my time messing with them.
Kevin, you pretty much got it covered, just to note, there is a pilot (mixture) screw on both carbs (your description was singular..) they were origanally covered with an aluminum plug, and if you only saw it on one, then the plug may still be intact on the other. if so, when you remove it, (and you will) please count the # of turns in to lightly seat it. we have very little info on what was the factory settings.
--Lucky
The low speed adjuster screw on the rear carb is hard to see and a little hard to get at . Take a look with a flash light to find it.
h2o, I see exactly what you mean. I am now experiencing the same flat spot that you are describing. Maybe I just wasnt wanting to find it there before but it definately is there albeit subtle. So I think you are on the right track going back to your original setup. I may try that as well. I've not been able to lift the tire in 1&2 yet sot I'll try your setup to see how it goes. I hope my suggestion didn't cause you too much headache. Seems like my problems are very inconsistent though. They come and go. How do you feel about using the same jets in both main air jets? I have the updated carbs w/ vacume airbox and understand that part of the update was a change in one of the main air jets. Have you tried other combinations for those? Any thoughts?
_H
My carbs and airbox are updated as well. ?The dealer in Steamboat - where I bought the bike - told me they had spent a lot of time on the carbs and had put the 135s in both main air jets. ?It sure seemed to be working well last summer. ?Still want to try that 125 in the rear carb (keeping both main air jets @ 135).
I think the fuel / air ratio needs to be different from front to rear because of the way the exhaust is set up. ?I don't know if you were considering going larger with the rear main air jet but that would just be using a larger volume of a similar fuel / air mix as the front carb. ?(make sense?)
No headache in your suggestions, just raised curiosity. ?Learning more about how to get the most out of these bikes is always a good thing - even when experiments don't quite work as intended.
H2o
Well I've got both carbs completely dissasembled and sitting in Barryman's ChemDip at the moment... perhaps tommorrow I'll have her running again. ?
Just to make sure H20, when you said 4.5 turns out for the mixture screws, you meant 4.5 complete (360) rotations?? ? I figure you did, but at the cost of taking the carbs off again to adjust that rear screw...
Thanks again yall.
By the way, for anyone who's used the Barryman's, is it supposed to be half separated and settled?? Mine needed a serious stirring and I'm not sure it did the trick. I went back to the store and opened a different can to check its condidtion and it looked the same. I still think somethings fishy.
Berrymans is normally half seperated & that's fine & normal. a few tips:
don't keep the throttle bodies in for more than an hour or you'll weaken the throttle seals, & we can't get replacements.
gently agitate the basket every 5-minuets
rinse the carbs well with a hose and blow dry with compressed air.
lightly seal the can while the carbs are in there, humidity & moisture shorten the working life of the dip. also don't store it on a concrete floor (don't remember exactly why, but I never have...advice from an old wrench I knew) put a piece of wood under it
I have 2 cans of it, one is a few years old. it seems the older this stuff gets the better it works...
--Lucky
Yes - I use 4.5 complete turns on both screws. But that is just to get it to fire up. You'll still need to adjust them further when they are on your bike and it's running. Find a long, skinny screwdriver to get to that screw on the rear carb. It is reachable. I get to mine by going in right above the black bolt that mounts the engine to the upper steel plate brace (right where the bottom of the bolt head and the plate meet) If you need to, you can grind down the edges of a wider screwdriver to make one suitable for getting to the little #$@&%^! screws. There are also flexible drivers made just for this purpose but I find them more of a hassle in this instance.
That B-9 is amazing stuff. I agree with Lucky, it gets better with age & use. It does eventually wear out but I don't know how many carbs or years it would take to do that. My can is at least 6 years old. Should last a good long time for those of us who rebuild an average of 3 or 4 carbs a year. I keep mine in my chem storage cupboard in the garage. Wood w/ vented door. Neighbors have learned that I know how to do carbs and I get the occasional request to see if theirs needs a dip & rebuild. Too bad I can't charge them my lawyer rates!
QuoteI have 2 cans of it, one is a few years old. it seems the older this stuff gets the better it works...
Hmmmm...Sounds a lot like motorcycle mechanics...
:-)
Greg
ok, so this conversation has gone from carb tuning to the age of my cans... your a weird bunch (probably why I hang out here)
Success. ?Fired her up today and she runs better than ever! ?1500-10,000 rpms free and clear. ?(except for the stumble... ::)
I suppose I should sync the carbs before fine tuning the mixture screws?
Also, should I wait to tune untill I get a real gas tank on there and ditch the Gatorade bottle rig I've got set up now? ?
I've been shaking bb's in that gas tank but have yet to figure out how to get the rust out that's now loose inside.
use one of those round magnets with a hole in the middle on a string, or other magnet set up. I left a magnet stuck to the inside of my tank just in case...
--Lucky
There are at least two kinds of Berrymans one is labeled" Not for sale in the state of California", thats the good stuff , I bought it in Wa. the OR.stuff is like the CA stuff.
Good going, Jon!
Just got back from my Yamaha dealer with the 125 jet for rear carb so I'll give that a try to see if my new flat spot goes away. Let y'all know what I discover later today.
Changed rear carb main jet from 122.5 to 125. 122.5 was just too small. Went for my reservoir test loop. Still some minor flat spots in hard acceleration but got rid of the major 4,500 - 5,000 RPM spot. What flat spots there are are all under 5K and the most noticeable is now down to 3,500 - 4,000, but it isn't very bad, just kind of a hiccup - less than 1 second. Enough to notice but over before I can think about it.
Think I'll leave it like it is for now and see if it smooths out over the next few days. Pulled very strong to redline in second gear. I only took it to 9K in 3rd (intentionally) and 8K in 4th. The meat of the powerband is very strong.
Additional info - Ambient air temp about 90 degrees F. Did not get much above 1/2 on temp gauge. Even at stoplights and signs in town, it didn't get above 3/4 - still well below the red zone. (Yes, I did come to a full stop with feet down at all red lights & stop signs ;D). Last year, it constantly ran from 3/4 to fan on. Differences are foam air filter, now leaner main jets (I'd think that might tend to heat things up a bit) and the big difference - synthetic oil. The Rick's stator is still doing great. Must have sealed my case right - no leaks @ 100 miles.
I used 1/2" heater hose hooked up to my shop-vac to remove the mouse poop and rice that the now dead mice had dropped in my tank over the winter. Good thing I brought it in the house instead of leaving it in the garage.