Wednesday, June 24, 2009
Virago vanity
So I worked on my Virago the last four days. It was fun, and the only reason I stopped is because I have to go to Augusta today for business and I'm waiting for parts.
(By the way, the bike is for sale and you can find out about buying it by emailing mickatum@aol.com).
First I ran through the regular small engine diagnosis. First removing the dead battery and putting it on a charge to see how dead it really was, I hooked up a car battery that I salvaged from the demise of Aimee's Mazda earlier in the year. Then we put gas in and tried for a start. No luck. Gas tank leaking from small rust holes. Try not to worry about it while testing other systems. Pulled the plugs, Good fire. Put them back in, still no start. Pull them again, squirt a little gas in each cylinder, replace plugs. The bike fired but wouldn't start.
Carbs or compression, then. Since it was stood for five years, I expected to have to pull the carbs. The motor turned over well enough and made all the right wheezy noises, although it was hard to tell because the starter was grinding loudly and kept kicking out. But there was no major engine damage to hear, a thrown rod or valve or anything like that.
First thing next morning, set the valve lash and check compression (by hand -- my compression tester is over at our other house sitting in the back of my old VW bus), then pull the carbs. Easier said than done. It took me four hours of trail and error, lacking a manual, to figure out how to get them off the cylinders and away from the engine and frame. That night I bought the manual off ebay.
Stripped the carbs. Yech. All tarnish and resin. The front vacuum piston diaphragm is torn in two places. Goop up the holes with glue, let glue dry. (Yes, this does work, if you are careful and use good glue -- you can also use a patch. Condoms make the best patches. No kidding!) Use same glue on gas tank.
While waiting for glue to dry, remove starter for the first time. Bench test. Seems fine, actually. the noise is in the engine case, where some kind of weird starter clutch resides. Re-mantle starter for now, because I need it to test my carbs.
Clean and reassemble carbs without rebuilding too deep, just for starters. I don't beleive in fixing too much. If an engine was running well before it sat, it can usually be made to run well again without getting in too deep or risking the chance of breaking something expensive. Reattach carbs to bike. try for a start. Starts and runs on one cylinder only. But this is progress. Gas tank still leaks.
Remove carbs again. Attempt partial rebuild without a rebuild kit (too cheap to buy one -- lets see if I need it first). Goop more glue on gas tank leakage.
Find sticking needle valve and detached vacuum piston needle jet. Obvious. Duh. I missed the needle jet on the first go-around because I was distracted by the torn diaphragm find. Lots of jets and passages. Clean them out as best we can, replace needle jet. Re-attach carbs, try for a start.
Bike will start, but runs badly and cuts out at idle. See gas pouring from carb. Needle valve stuck open. Gas tank leaks from new place, from the petcock, now we have vaccum on the automatic shut-off valve. Fix that by massaging the petcock vacuum valve gasket with veggie oil. You'd leak too if you had to sit and dry up for all those years. Guess I'll have to pony up for that carb rebuild kit after all. Consult computer. $180 bucks OEM, $38 on ebay. Go figure. Order rebuild kit from ebay. Also order new battery. I figure now I can get this bike running, so it's worth the $58 investment.
Yes, the bike will run well enough when I get the carbs dismantled and remantled a fourth time, with the new needle valves in the rebuild kit. Now let's fix that starter.
Read up on Virago listserve threads on starter problems. Sounds complicated, but faint heart n'er won fair lady.
Remove starter a second time, dismantle on bench, JB Weld (epoxy glue) rig gear to main washer as detailed in http://www.drpiston.com/81_83_Starter_Paper.html
Thank you Dr. Piston. What would we do without the Internet? How did we live before?
And what would mechanics do without JB Weld?
While waiting for glue to dry, remove right engine cover. This is the first time since about 1979 that I've been this deep in a motorcycle engine. Lots of other engines, of course, but not motorcycles. But it's all coming back to me. Find weird starter clutch thing. Puzzle it out, with aid of Dr. Piston.
Use Dr. Piston's patent starter spring-cutting fix to reduce resistance on starter throw out gear. If the gear can throw itself out easier, and engage more positively, then it won't detach from the flywheel so quickly or make that grinding noise. Seems risky, but I can see it will work.
Carefully reassemble engine cover. Put in fresh oil. Try for a start, leaky needle valve not withstanding. Rear cylinder hydraulics. Too much gas in cylinder from float valve needle.
First hook up bike to car battery while car is running, jump-start style. The Mazda battery has been sitting in the shop for three months already, although I keep putting it on a trickle charger so as not to waste it, it still doesn't last long. If we get a stronger battery on the job, we might get an easier start. All the listserve threads emphasize that the Virago has a weak starter system and weak ignition and so needs an exceptionally good battery to make up for this.
Cylinder still hydraulics.
Pull the plug, turn engine over to remove surplus gas. Not so bright. Gas sprays in face. Glad I'm wearing my shop teacher glasses. Aimee will get a laugh out of this. Emergency run to sink to wash off gas, and now I stink like a refinery. Oh well. Builds character.
On return to bike (glutton for punishment), replace plug, try for a start, bike starts and runs well enough except for the failure to idle, which is to be expected with a leaky needle valve, and the starter noise is gone.
Dr. Piston, you rock. And I should know. I'm a doctor.
So it looks like I got a decent bike here for $200 plus $27 (manual) plus $38 (carb rebuild kit) plus $58 (battery) plus some glue and oil. A bike worth about $500-600 on the market, from what I can tell. Including five-six days work. Far less than minimum wage, but the practice at being a mechanic again, and the pure Zen is priceless.
Problem is, this bike is too big. I want a smaller, more efficient and easier to handle street bike. But by the time I get that new battery and rebuild kit in, the thing should run start and well enough.
Anyone want to buy a Yamaha Virago or trade a smaller bike?
I guess I'll have to get on Craig's list when I get those new parts in.
2 comments:
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Hi, I am Chet Martin in Frankfort Maine. Just read the Virago bit. I tinker with motorcycles too. Actually have a nice yamaha xs 400 you might be interested in. It is quite a bit smaller than the Virago. 400 twin with 3 valves percylinder and single overhead cam. I got it a little while ago and have cleaned the carbs completely by soaking in a gallon can of cleaner from autozone. (that stuff works really well) Also bought a new battery but haven't installed it yet. Bike needs seat covers and tires but all signals, headlight and taillight are intact. It has the low cafe style tank and has aluminum alloy wheels. Looks pretty nice. I would be working on it still and probably have it running if i hadn't found such a deal on a suzuki intruder 1400. I hope to get my wife on the back of the suzuki and do some touring with it next year. Please let me know if you are interested in the Yamaha and I will send some photos.
ReplyDeleteTake care,
Chet
You can buy the Virago for cash if you like. Email mickatum@aol.com.
ReplyDeleteIt will have it's safety inspection done next week. The only remaining problem is a ground leak that drains the battery slowly, which will have to be diagnosed very carefully, step by step, using a multimeter.
I am not much interested in your Yamaha, though. I don't need a Cafe racer style bike (crotch-rocket!). What I need is an 80 mpg commuter bike.