miss firing

[chopzuki]

Hey all I'm new to this site, this is my first post. And reading everything on here and basscliffs site has been very helpful in getting my bike running right utd. I have an 81 gs650g with pod filters and 4-2 open exhuast. I put 125 main jets in it in hopes to get it running better, and the top end is much improved. But I discovered my #1cylinder (sitting on bike, far left cylinder) is not firing. It had spark, and fuel. But cruising at any speed or an idle I can grab the exhuast pipe without even coming close to burning my hand. I haven't checked my valves yet, waiting on shims and a feeler gauge. But could a dead miss be caused by the valves?? Any help is appreciated. Thank you.

[hampshirehog]

Hi. If she runs fine on WOT it's probably a blocked pilot circuit. But you are wise to check those valve clearances - do that before doing anything else.

[chopzuki]

I rebuilt all 4 carbs 2 months ago. Still misses regardless of rpm

[TheCafeKid]

I rebuilt all 4 carbs 2 months ago. Still misses regardless of rpm

Check the pickup tube and it's corosponding port in the float bowl. Sometimes you need to take a strand of copper wire and run it down that tube to clean stubborn crud out of it.

Adjust your valves.

And fiddling around with trying to jet those carbs by hand is an effort in futility. You'll likely give up before you get it. The stock needles are just not designed to work with pods. See if you can find a Dynojet kit.

[chef1366]

See if your spark plug boot is threaded into wire and not burnt rubber.
Is there fuel leaking out of the rear of it? If not the pilot jet is clogged. Take it out and see if you can see light through it.

[chopzuki]

The pilot jets are new 2 months ago. After a run, if I pull the plug its wet with gas. And I checked the spark and it has spark too.

[chef1366]

Just for sh!ts and giggles unscrew the spark plug boot and cut the wire a little and rethread it into fresh wire.

[BassCliff]

Greetings and Salutations!!

Hi Mr. chopzuki,

I rebuilt all 4 carbs 2 months ago. Still misses regardless of rpm

I hate to harp on this, but did you clean the carbs properly? Or did you just stick in some aftermarket "carb kits".

Mikuni BS(CV) Carburetor Rebuild Tutorial
(Mr. Nessism)

CV Carburetor Rebuild Guide
(Courtesy of GSR and John Bloemer)
(Click here to see the CV Carb Notes)

I have seen in this forum where members have had to clean their carbs two or three times to get them properly clean, soaking in carb dip for up to 24 hours.

Now let me dump a TON if information on you and share some GS lovin'.

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Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

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Thank you for your indulgence,

BassCliff

[chopzuki]

Well thank you for such a nice welcome. This truly is the best forum I've found to date. And I unfortunatly didn't soak the carbs, though I did clean scrub and blow them out with air before the new guts. And I noticed today the dead cylinder pops on deceleration, not sure if that meaNs anything. And random question but what could prevent me from seeing through my oil sight? Cause as of right now I can't see through it lol

[cowboyup3371]

The oil sight is just years of crud and build up. Take the cover off (get a new gasket) and clean it out with a qtip and cleaner. Or, you can just order a new glass and replace it. Search on here for the tips on doing that.

I would also recommend you look at those wires like was mentioned AND CLEAN THOSE CARBS PROPERLY

[Steve]

I haven't checked my valves yet, waiting on shims and a feeler gauge.

Just wondering how this works?

If you haven't checked the clearances, how did you know what shims to order?

I really, REALLY hope you did not waste your money on a "shim kit" that has two of every size made.

Until you KNOW what sizes you need (and how many of them) you should just go down to the corner auto parts store, get a feeler gauge set (make sure it goes thin enough), and start measuring.

By the way, I have FIVE GS bikes to keep going, and have spent less on shims for all of them over the last six years than the cost of the shim kit.

And, ... also while you are waiting for your feeler gauge, feel free to take advantage of the offer in my sig.

.

[Steve]

But I discovered my #1cylinder (sitting on bike, far left cylinder) is not firing. It had spark, and fuel. But cruising at any speed or an idle I can grab the exhuast pipe without even coming close to burning my hand.

I think you answered your own question without realizing it.

And I unfortunatly didn't soak the carbs, though I did clean scrub and blow them out with air before the new guts.

There is NO WAY you can properly clean the carbs without dipping/soaking the carbs.

The passages that get clogged are deep inside the carb body, so no amount of spraying, scrubbing and blowing will get them clean. They have to be soaked long enough to get the crud soft enough to spray out. Depending on how long the bike was parked before you got it, that can take a full day for each carb.

.

[chopzuki]

Believe it or not I leaned out the airscrews and it cleared up. And all my valve clearances were within spec. Less than 4 thousand original miles on the bike and it shows

[BigD_83]

Believe it or not I leaned out the airscrews and it cleared up. And all my valve clearances were within spec. Less than 4 thousand original miles on the bike and it shows

Was the #1 sparkplug wet then before (flooding) ? [EDIT- went back and reread the thread and saw that you already said that it was]

By leaning out the airscrews you may be covering up another problem. Keep an eye on the plugs, because burning up the valves by running lean is a whole world of another problem. These bikes are known for being setup lean from the factory...the stock pilot mixture screws setting is 1 1/2 turns out, and I've read many accounts of members ending up with them at 2 1/2 to 3 turns out using the highest idle method.

[Steve]

Believe it or not I leaned out the airscrews and it cleared up. And all my valve clearances were within spec. Less than 4 thousand original miles on the bike and it shows

Since you don't have any "air screws" on the bike, I am wondering what you turned and which way.

If you turned the "idle mixture adjustment screws" anti-clockwise, you actually RICHENED UP the mixture.



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