Question about 1980 Yamaha XS 650 G

2 Answers

Hi I have a 1985 Yamaha xs 650.It is back firing out both excusts. Left cyl spark plug is wet with fuel. Right hand cyl is running hotter.Bike starts ok but back fires on Idle both cyl... Hope you can help.... thanks

Posted by on

2 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Governor:

    An expert whose answer got voted for 20 times.

    Scholar:

    An expert who has written 20 answers of more than 400 characters.

  • Expert
  • 185 Answers

There are several reasons for backfiring, your sounds like either a faulty spark plug or coil. Another thing to check is the Carby Float Level on the Left Cylinder. This might sound a little funny but if you haven't rebuilt the topend of the engine I would look at a slightly colder spark plug not hotter. When fitting new plugs, check the gap but it should be OK from the manufacturer. Please resist closing the gap by banging it on a hard surface, it can fracture the new plug and you will be back where you started.

Posted on Nov 13, 2009

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 881 Answers

Well the most problems are in the carbys {running to rich or to week} and with 2 carbys you must have them in tune with each other by about 98%.
and with a plug getting wet your float level is to high so when your going the fuel is getting to much in that cylinder and putting out a strong mixture and the other one to weak and you could also have a gasket on the intake sucking air or the exhaust has a bad flang gasket or a small pin hole in it some where
WHEN idleing put your hand over the tailpipe and stop the exhaust and see if you can hear a small blow if so fix it and the same the other side.
AS ITS ALL TO DO WITH HEAT AND INCORRECT MIXTURE so L/H is to much fuel,,,R/H cyl is running almost correct but wants tuning.
Have a goodday RON

Posted on Nov 13, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Had carbs rebuilt on my 1975 Yamaha Xs 650 now the left side cylnder fires infrequently and backfires loudly with new plugs. could this be a timing issue?


If it's just one cyl, then I doubt its timing.
Check to make sure the carb boof is tight and not leaking
also check any vacuum hoses.

Oct 12, 2010 | 1978 Yamaha XS 650 E

1 Answer

Xs750 what is the firing order


There is no firing order. Your bike has a coil that fires on both the compression stroke and the exhaust stroke (also called a wasted spark). Therefore either plug wire can go on either cylinder and the bike should run the same.On four cylinder bikes this meant that you could run four plugs using only two coils and two sets of points instead of four coils and four points.If the bike is running poorly try new spark plugs and new spark plug caps first(start with the cheap stuff). Next check the actual coil and pulse pick up or points. You may have to replace the coil only because the wires are cracked shorting.

Jul 25, 2010 | 1979 Yamaha XS 650 SF

1 Answer

My 650 yamaha specail has a miss fire on the right side not all the time under power it dont do it just at an idle and when you give it a little gas help


There is a resister in the spark plug caps that can cause a problem, try swapping the caps left to right and see if the miss changes side, the caps unscrew off the leads, if there is enough lenght cut 10mm off the end of the leads, when you screw the caps back on

Jun 02, 2010 | 1979 Yamaha XS 650 SF

1 Answer

I have been building a chopper out of this model bike, have the bike complete but it isn't starting. It trys to turn over but it wont fire up.


To begin with you need a good battery @ 12Volts.
Check if there is spark at the spark plugs.remove one spark plug and earth it (spark plug body) and crank start and observe for the spark.
Check if fuel ( gas ) gets into the combustion chamber.
Try cranking it and thn remove the spark plugs and check if they are wet with gas.
Basically these are two things to check first.
Hope this helps!,
Let me know of the outcome and hope to be of help further..Thks.

Nov 29, 2009 | 1983 Yamaha XS 400 L Maxim

1 Answer

No start- power to all spark plugs but I see the


is there 4 cylinders also try taking the carbs off and stripping it down and cleaning it up sometime **** gets into them and clogs them up get back to me with results

Oct 21, 2009 | 1981 Yamaha XS 650 H

1 Answer

1980 xs 650 . bike wont start, turns over but wont catch. the guy i bought it from told me it was running when he parked it three years ago. he also told me that he thought it might be the wiring?. i am a...


ck to see if you are getting spark. If not, ck the coils for wire connections and juice while cranking. If you have spark, the coils are fine. Make sure you are getting fuel..

Jul 10, 2009 | 1980 Yamaha XS 650 G

1 Answer

Right side brake only releases when bledder hole is opened. tryed 2 calipers. left side works fine.


presure release passageway in master cyl is clogged or damaged.remove from bike take appart and clean.

May 08, 2009 | 1980 Yamaha XS 650 G

1 Answer

Firing order for yamaha xj650 1981 motor cycle


without a manual can you set-up the timing mark on flywheel
an see what cyl is compression stroke to find #1 cly

coil 1 are spark wires 1 and 4 cyl

coil 2 are spark wires 2 and 3 cyl

now if still have trouble then (if same plug connection) switch the around inlet plug on coils form bike wire harness or swap spark wires

Apr 10, 2009 | 1981 Yamaha XJ 650

3 Answers

Getting my bike started


Hi,
The # 1 cyl is on the left side as you are sitting on the bike. Firing order does not really apply to these motors as the coils fire twice per cyl. The left coil will fire 1 & 4 the right coil will fire 2 & 3. I usually hook them up as follows: Left outer to #1, Left inner to #4, Right inner to #2, and Right outer to #3
Here is a good site on XJ's
http://www.geocities.com/MotorCity/Speedway/7795/xjfaqbig.html
I hope this helps

Apr 07, 2009 | 1980 Yamaha XJ 650

Not finding what you are looking for?
1980 Yamaha XS 650 G Logo

423 people viewed this question

Ask a Question

Usually answered in minutes!

Top Yamaha Experts

dhnguyen

Level 2 Expert

281 Answers

Steve Sweetleaf
Steve Sweetleaf

Level 3 Expert

1144 Answers

Tony

Level 3 Expert

2600 Answers

Are you a Yamaha Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...