QuestionQUESTION: Hi Folks, I have a 1982 Virago, It was what my kids called a Basket Bike, since much of it came in a basket.
Anyway, I rebuilt the carborators but do not know what the the initial setting for the Idle Jet (It will Not Start) - About how many turns open should I set the Jets.
Thanks
Tom Taylor
ANSWER: Please give lots more history and explain what you mean by it will not start... A good starting point for any pilot air adjusting screw is 1.5 turns out, but if the pilot jets are physically clogged then this won't matter and it might not run... this requires running a small diameter wire through all jets to clear their inner orifices.... but, again, give me lots more info.... what do you mean does not start ???
P
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QUESTION: I got her started over the weekend,
- The Jets are probably not actually Jets - they may be the Idle Air Adjustment. They are set closer to 4 turns open to get it to sart (I started at Two turns and kept opening a half turn until it finally popped on one cylinder)
During the rebuild, the carb's were Cleaned and all passage ways were cleaned out with Carb Cleaner. New jets were installed as well. (Hi & Low Speed)
It now starts, reasonably easy (For a Virago,) but tends to have the rear Cylinder Drop Off if it idles for a minute or two. (Syncronizing the Carb is a Nightmare as well.)
The Rear cylinder also starts to miss when you are coasting or running at 2000 to 2500 RPM at low trotle.
The Front cyliindar Backfires out the exhaust on mild to heavy Decelaeation.
BUT --- It Runs great during accelleration
Tom
ANSWER: I'm going to bet this bike has an aftermarket exhaust system.... the decelleration popping is from leanness at the idle circuit and the throttle cutaway circuit. This is almost always due to the idle circuit being too lean, you should gey a manual and adjust the carbs per the manual. You might need to get a couple of steps richer pilot jets and maybe main jets too. If the plugs are showing white and ashen coloring then it is too lean. The jet needles can be adjusted woth very small shims to aid in enrichening the 1/4 to 3/4 throttle settings as well... this would all depend, of course, on the bike being too lean as I believe... One note, in 1982 all yamahas came too lean and benefitted from jetting richer. One other piece of history which is peculiar to the 1982 Yamahas is they were shipped, from Japan, with fire retardent in the fuel system and inside the carbs. We, at the ZYamaha dealership service departments in 1982 had to do full carb rebuilds and complete jet cleaning and clearing on every Yamaha street bike that we got !
Not good, and this could be part of the issue you have as well.
Thanks.
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QUESTION: Yes to the more open exhaust system.
However earlier this year, I was able to open the Needle valve on that (front) cylinder,which stopped 99% of the exhaust Popping. Unfortunately, The adjustment on the Front Cylinder seemed to knock the rear/Left Cylinder out of adjustment.
It was downhill from there.
That is when I rebuilt the carbs and Jets. I also rebuilt the Factory Fuel Tank Valves at the same time. I had replace them last year with aftermarket valves with an Off Switch. I've had 3 quarts of fuel in the Oil in the past prompting the Valve Change. The Carb Floats Valves seem to be weak in this model as well.
Should I rejet the Idle jets with a bigger ones. They have 41's in it now. What size would you suggest.
FYI I have removed the Vacuum Leaning Gizmo on the front carb as well. (Why did they only put it on one carb?)
When I put it back on recently it really ran like crap. In the past it didn't seem to matter where it was attached or not.
Regarding your note to go to the manual- The Manual I have simply states that you should "not change the factory setting"...
When it was running, >>> It ran well.
- I even purchased a full parts bike it looks like I'll Need it
Thanks, Tom T
AnswerSorry to get back to you so late...
You say you have a parts bike, do you have the stock carbs, air filter and exhaust ?
I would like to see you get as close to stock as possible.
Also what are your compression ratings ? are they in spec ?
Sounds like the intake and exhaust have been screwed around with a lot and if you can you need to back this up a bitt...
