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ViragoTechForum.com Tech Help Major trouble with front cylinder (SOLVED)

#1:  Major trouble with front cylinder (SOLVED) Author: usehername Post Posted: Sat Jun 26, 2010 6:57 pm

When I bought this beast I knew it was not running quite right. It seemed like a tune up would solve the problem but after cleaning the carbs, setting the valves, new plugs and an oil change I am at a loss. Here is whats happening. After the above service the bike fired right up but not smooth. I left it sit overnight and next day I got a lot of white whispy smoke out of the exhaust. Later it stopped but the front cylinder went cold. Fuel on the plug and fuel dripping from the exhaust. I have swapped the plugs to no avail and have ok spark. more on the rear but surely looks adequete. I could not get the front to fire after playing with the pilot screw until I drained the bowl and started it again. It would get hot but I was back to the white smoke. It is not like oil burning smoke. It last quite a while after the bike is off. Ususally coming out of the top pipe which is actually the rear cylinder but the fuel dripping comes out of the first joint on the front pipe near the collector. Any advice would be great.

#2:   Author: anaman51 Post Posted: Sat Jun 26, 2010 7:15 pm

Check the plug wires for corrosion where they link up with both cap and coil. On anything else, you might get away with an "okay" spark, but Viragos demand all the spark it can generate. Also, any time a cylinder stops firing but the engine continues to run, you run the risk of gas in the crankcase oil. Check your oil---if it smells even remotely of gas, drain it. Put it on the centerstand and check the level. If it's higher than it was the last time you looked, drain it. You do not want to run the engine with gas in the oil. Also sounds as if the floats might be set a tad high, or are sticking. Check out the New Tech Tips (red squares in left margin) for how to set them with the carbs either on or off the bike. You can easily check to see if they're set right by using this: Float adjustment.

Dan


Last edited by anaman51 on Sat Jun 26, 2010 7:25 pm; edited 1 time in total

#3:  Re: Major trouble with front cylinder Author: usehername Post Posted: Sat Jun 26, 2010 7:19 pm

so far no indication of gas in th oil. plugs were changed.

#4:   Author: anaman51 Post Posted: Sat Jun 26, 2010 7:28 pm

I was sloppy in posting, and had to edit and re-edit to get it to say what I wanted it to. Check out the link. Sorry 'bout that.

Dan

#5:  Re: Major trouble with front cylinder Author: usehername Post Posted: Sat Jun 26, 2010 9:03 pm

I guess I will yank the carbs yet again. I think I would sooner chew my leg off. Enough for tonight. back to it in the am.

#6:   Author: nraluke Post Posted: Sat Jun 26, 2010 10:06 pm

May be as simple as stuck float. Before you yank those carbs I'd reset the mixture screw for that front carb to 2 1/2 turns out from soft seat, drain the float bowl, close drain screw, get a plastic screw driver handle and turn fuel petcock to prime while tapping on side of front carb float bowl with the screw driver handle. After about 1 minute turn petcock back to on, put in some new ap63 plugs gapped to .029 start her up and see if the smoke clears after a couple minutes. Will take a few minutes to clear all the gas in the exhaust.

#7:  Re: Major trouble with front cylinder Author: usehername Post Posted: Sun Jun 27, 2010 11:17 am

Well the float is definately not closing. I took it out and the tip looks fine. I cant see why it wont close. It was closing before I cleaned the carbs.

#8:   Author: nraluke Post Posted: Sun Jun 27, 2010 12:04 pm

Did you install the carbs with gas in the float bowls? That helps to keep floats from hanging up. While you have the carbs off I'd check to see if there is to much play on the float pivit pin which would let the float move side ways and hang up. Also, if float drop is to long then the float needle valve may cock and hang up. With bowl installed, I'd turn carb upside down and blow into filler inlet to see if valve is sealing. If it,s not sealing then float is hanging up or needle valve is cocking. Tap float bowl and try blowing in inlet, if it seems to be sealing then I'g go ahead and bench set float heights, set the carbs in a position that matches how they would hang on the engine. (I clamp a piece of plate in vise and clamp the 2 carbs connecting bracket to that) hook up a filler (i hang a funnel with a hose connected to it and attach to the fuel inlet) fill with gas while tapping float bowl (if float valve isn't sealing then you will see gas comming out carb) then with some gas still in funnel i use clear tubing to ckeck float height. Once i get it where i want it then i install carbs with gas in float bowls. After installed i turn petcock to prime and tap on float bowls then turn petcock back to on, fire her up and see if all is well.

#9:  Re: Major trouble with front cylinder Author: usehername Post Posted: Sun Jun 27, 2010 2:48 pm

I tore verything down polished everything and bench tested the float. It seemed to seal fine so I mounted the carbs with gas in the bowls. Started right up with both jugs hot but shortly after a couple minutes I got serious white smoke again. Letting it cool down now. Oh changed the oil again too. Thanks

#10:   Author: anaman51 Post Posted: Sun Jun 27, 2010 3:41 pm

Very puzzling. It's going to require someone with more knowledge than I have, I'm sorry to say.

Dan

#11:  Re: Major trouble with front cylinder Author: usehername Post Posted: Sun Jun 27, 2010 4:45 pm

Update:
I pulled the plugs. both were carbon fouled. So I reset the pilot screws to what I thought were rediculous (1 turn out on the rear and 1/2 turn on the front.) Those were factory settings if nothing moved. Fired right up, no smoke, and good response. I will sync the carbs next and hopfully call this one solved.

#12:   Author: usmc_dad_0341 Post Posted: Sun Jun 27, 2010 4:58 pm

Years ago I had a similar problem. Bike had been stored with fuel in the carbs by the PO.. That fuel combined with the salt sea atomoshpere, and severely gummed both carbs but the #2 one in particular.

I cleaned both carbs using an old school (read strong - heavy duty, chems-no-longer-available) carb cleaner three times over. To no avail.
Learned a lot about pulling Virag carbs. Got so good at it that I could pull and re-install them in <40 minutes! Each effort produced mixed results. Numerous float level checks, float "bind" checks, etc., but always the same results. My bike ran like shyt.

I finally solved the carb issue when I had a buddy dunk the carb that fed my #2 jug (front) and clean it with his ultrasonic cleaner. A minor passage in one carb was probably clogged. However, by this time the carb holders were so shot from the abuse of "put on, take off, x 3," that I had an immediate intake leak.

Faced with buying new carb holders, I threw in the towel and opted to go with the P901 Intake and an HSr40 carb.

Chief, out

#13:  Re: Major trouble with front cylinder Author: usehername Post Posted: Sun Jun 27, 2010 5:39 pm

Well not so fast... I synced at idle with the left and right adjusters no problem. whilst adjusting the center sync screw at 3000 rpm it just died. I thought I screwed something up with the sync screw but as luck would have it I forgot to switch the tank to prime and was out of gas. This is where it gets bad. I switch over to prime an restart and soon I get the front jug dead again. Shut it down and gas is spewing out the front carb. I guess once the float travels to it's lowest limit, there is a good chance it will hang up. So I have a stuck float valve again. One step forward and two steps back. What a weekend...

#14:   Author: club_c Post Posted: Sun Jun 27, 2010 6:26 pm

Drain that carb again with pet on 'on', then refill again on 'pri' while tapping on the side of it with the screwdriver handle. That should pop it loose. Try it before pull them off again.

#15:  Re: Major trouble with front cylinder Author: usehername Post Posted: Sun Jun 27, 2010 8:13 pm

I did as Club_c suggested. Freed up the float. Took it for a short ride. Seems to be OK. I guess I better keep the tank full I will finish tuning next weekend. Thanks for all your help.

#16:   Author: funkamongus Post Posted: Sun Jun 27, 2010 8:23 pm

If it hangs up on you again, pull the float pin and gently scrub it with green scotchbrite or some steel wool.

#17:  Re: Major trouble with front cylinder Author: usehername Post Posted: Sun Jun 27, 2010 8:28 pm

I cant believe I did not think of that when I was polishing the valve. Thanks that is a great tip.

#18:   Author: funkamongus Post Posted: Sun Jun 27, 2010 8:34 pm

Youre welcome, Brother! just to be thorough, too, are your needles and jets side specific? Mine are. The PO had mine in backwards, starving the rear, and drowning the front. Club C caught that one for me.

#19:   Author: club_c Post Posted: Mon Jun 28, 2010 10:04 am

usehername wrote (View Post):
I did as Club_c suggested. Freed up the float. Took it for a short ride. Seems to be OK. I guess I better keep the tank full I will finish tuning next weekend. Thanks for all your help.
Yay. Please put 'solved' in the title now.
ViragoTechForum.com Tech Help Major trouble with front cylinder (SOLVED)


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