1983 yamaha varago 750 foul plug

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1983 yamaha varago 750 foul plug

by bt2dahd :: Rate this Message:

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I have a 1983 yamaha varago 750. It stay in the shop all the time. The carbs have been clean and lean out out. It still keeping foul out the rear plug. The motor cycle shop can not seem to get it right. Can you please give me some ideas so I can tell them so I can ride my bike before summer passes.

Re: 1983 yamaha varago 750 foul plug

by yamaguzzi :: Rate this Message:

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our electrical systems are weak and so they must be in top condition before they run..meaning,,new plugs, preferably bosch 4237 or autolite AP63;;next is a battery that is two years old or less,(unless it is the gel battery which i have heard lasts up to 5 years), make sure all connections are clean,,take your sparkplugs out and ground them to the cylinder head,,,what is the condition of the spark? yellow and weak or blue and bright? if weak and yellow you may need sparkplug wires,,have them check the condition of you coils, a simple compression test will indicate the condition of your rings, it should be around 150psi, per cylinder, shouldnt be more than a few pounds off between the two,,and if its close to 100psi its due for rings,,using wd-40 spray the hoses and boots around the intakes to try and detect any vacuum leaks,,that will reveal itself by a change in rpms,,and of course the o-rings in the pilot air screws have been replaced, float level in the rear carb is where it should be,,an accurate method of checking this is to take a length of clear hose and attach it to the drain on the carb,,next hold it up above the carb while opening the drain screw on the side of the float bowl,,the fuel level should be right at or just below the seam where the float bowl meets the carb body. is the tachometer behaving? usually if the tci (the brain) is going bad it will reveal itself by faulty rpm readings,,jumping etc. it can be rebuilt...check all these things and let me know what you find in detail..take care good luck,,,yg

Re: 1983 yamaha varago 750 foul plug

by bt2dahd :: Rate this Message:

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Hi,

I gave the information that you gave me to the mechanic. He said, That he change coil packs it runs ok for awhile then it starts again. He said, That he has rebuilt the carbs several times over. He did a compression test on the cylinders an one cylinder was 80lbs ofd compression while the other one was 90lbs compression. He said, he adjusted the valve on 80 cylinder one and it came up to 90. Now there both up to 90lbs compession and still doing the same thing. He does not know what to do now.
Is it time for me to give up on this bike??? I do not see any oil burning. CAN YOU HELP ME PLEASE.

Thanks
Jimmy

Re: 1983 yamaha varago 750 foul plug

by yamaguzzi :: Rate this Message:

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re-direct the ground wire from the battery to a new location on the frame...remove and clean the regulator/rectifier.90psi of compression is low and you need to consider new rings this next winter. you are still fouling the rear spark plug?..what is your typical ride? is it mostly in town riding 1st 2nd and 3rd or highway riding?  what rpm do you maintain during your ride?2000  3000....keep in touch yg

Re: 1983 yamaha varago 750 foul plug

by bt2dahd :: Rate this Message:

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Right now I have not been able to ride it. The mechanic says, It will run ok then next thing he knows it starts acking up again. I believe that it goes back in force. When I had it in my possession, it ack up on the rear plug. I would put about 35 miles on it when this happens.

jimmy

Re: 1983 yamaha varago 750 foul plug

by bt2dahd :: Rate this Message:

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P.S.

I have only rode it around town and not on the interstate. I keep it around 3000 to 4000 rmp.

Re: 1983 yamaha varago 750 foul plug

by yamaguzzi :: Rate this Message:

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