I agree with your "two sides to the story"...I am a do-it-your-selfer" from the get go...

I was just commenting on the recurring, nightmare, ground hog day, post:

"I just switched air cleaner, and exhaust and re-jetted the carbs, and now the bike runs like crap"

I bet not only the GS twin  chat group, but every motorcycle group has this recurring post!  And then plenty of car chat groups too!  Then there are all they guys who F*** up and don't belong to any chat or who don't bother to post.

But hey, I just recently got into an automotive business...so the more guys F up, the more stuff I sell!

Seriously though, carburetors are sometimes almost a black art.....some guys can figure them out, and others should stay far away.

I remember messing with the SU carbs on my old '68 Triumph Spitfire...those f****ing needles!


Cookie

Quote from: MNgs500 on September 25, 2014, 02:24:54 PM
Even though this shot out of topic, i agree and disagree.
1) Messing with the carbs: To many who do this which include me are mechanical skilled and like to see how the bike works. I wanted to be a mechanic for years before deciding to get into engineering. I have owned 3 cars and do all the repairs myself. I can call myself a car/bike enthusiasts because its only what i care about. I like giving it a personal touch so the exhaust was one which required rejet. This is my first bike and first carburetor I have owned so like most said its a learning piece.

2) Don't touch the carbs: This is key to someone who likes to ride. Carburetors as i learned are very touchy and require knowledge and skill to work on them. In my example doing this procedure wrong can effect other parts like burnt valves or leaned pistons. If I could start again I would have had a mechanic rejet for me.

But since I'm a person that refuses to bring bikes/cars into shops unless last resort to save money.

That one has a M10 fitting for our size spark plug holes so it will work OK.  I bought this one earlier this year and liked it:

http://www.harborfreight.com/Compression-Test-Kit-8-Pc-69885.html

Had one for decades that got lost or loaned or something so I needed a new one.

Just go down to Advance Auto or similar...they will "loan" you a compression tester for free....

Well, you have to pay for it up front, but you get all the money back when you return it...

should have adapters in the kit...

Cookie

Quote from: MNgs500 on September 25, 2014, 02:24:54 PM
Even though this shot out of topic, i agree and disagree.
1) Messing with the carbs: To many who do this which include me are mechanical skilled and like to see how the bike works. I wanted to be a mechanic for years before deciding to get into engineering. I have owned 3 cars and do all the repairs myself. I can call myself a car/bike enthusiasts because its only what i care about. I like giving it a personal touch so the exhaust was one which required rejet. This is my first bike and first carburetor I have owned so like most said its a learning piece.

2) Don't touch the carbs: This is key to someone who likes to ride. Carburetors as i learned are very touchy and require knowledge and skill to work on them. In my example doing this procedure wrong can effect other parts like burnt valves or leaned pistons. If I could start again I would have had a mechanic rejet for me.

But since I'm a person that refuses to bring bikes/cars into shops unless last resort to save money.

The carbs are not touchy at all ... In fact almost the opposite ... you can be off by a good bit and still ride without any apparent problems. That's why they put 122.5/37.5 in US bikes.
In a lot of cases people dont know what the fuel mix is past that start up and idle bit.
If they put different jets - in Canadia which has the same gas as we do, they put euro jets in.
Hey if it will make you feel better, ride into canadia and tell them to set your carbs to "stock".
That way you can own the only stock GS LOL. If its stock in all other aspects.

Of course I never bought a new GS so no clue, all of mine had been through hell and survived, long before I dragged it out of the ditch and got it home ...

Cool.
Buddha.

Buddha,

Easy for you.....not easy for everybody.

If it was easy, there would not be so many posts about AFU jetting...

You pointed out that the jetting ( mixture)  has quite a range which still works fairly well...so why so many guys really F up?

Cookie

Left intake

Right intake
Right exhaust
Left exhaust

By the looks it seems the left exhaust isnt pooking good. I did the flashlight test in the dark no light.

OK That white valve = lean.
Nothing is burnt - you will easily see burnt ..
OK that white one chamber needs jetting corrected - see that choclate color on the other one ... nice - valves hold color a lot longer than a spark plug. So you cant say its lean @ idle or in the mid or up high ... its lean somewhere where you spent a good bit of revs, and you have not run it in the rich range (if it even is rich anywhere) OK ... so jet it right and you should be fine.
Cool.
Buddha.

Quote from: twocool on September 25, 2014, 07:58:04 PM
Buddha,

Easy for you.....not easy for everybody.

If it was easy, there would not be so many posts about AFU jetting...

You pointed out that the jetting ( mixture)  has quite a range which still works fairly well...so why so many guys really F up?

Cookie

OK fine - since you're calling me a Genius here ...
Cool.
Buddha.

LOL!

"Genius"?  Stronger word than what I was thinking, but...

Ok...if my post implies "genius"   I'll go with that!

So then what do we call all the guys who F up their carbs?   


Cookie

Quote from: The Buddha on September 26, 2014, 06:01:08 AM

Quote from: twocool on September 25, 2014, 07:58:04 PM
Buddha,

Easy for you.....not easy for everybody.

If it was easy, there would not be so many posts about AFU jetting...

You pointed out that the jetting ( mixture)  has quite a range which still works fairly well...so why so many guys really F up?

Cookie

OK fine - since you're calling me a Genius here ...
Cool.
Buddha.

So next step is it to compression test now if ot fails on the left like the shop said what to do next?

Here it is finally got the head off. Cpearly the left exhaust valve is burnt. Now based on this what will i want to do? The shop said if i bring the head in alone as is they can replace it for $100+ parts.

Dude that's not burnt
You're lean, but jet it and it will simply forget it was run lean.
Burnt = edges will be looking chewed ...
Even more burnt = the face wil lbe chewed.
That is a mighty fine valve.
Anyway now that you have it apart, get a 3 angle cut and put it back on.
Oh, yea, a burnt valve cant be cut either ... anyone who says your vale is burnt, and here give it to me and some $$$ and I'll cut it for you is stealing your $$$.
Cool.
Buddha.

Quote from: MNgs500 on October 22, 2014, 03:42:59 PM
Here it is finally got the head off. Cpearly the left exhaust valve is burnt. Now based on this what will i want to do? The shop said if i bring the head in alone as is they can replace it for $100+ parts.

you're gonna need a valve compression tool. and a torque wrench. and a new valve. if you're hellbent on replacing it*

also, whats + parts? are they replacing all the gaskets/crush washers? honestly if they aren't and can get away with just replacing the valve, i'd just bite the buck and take their offer. just to get the valve compression tool alone is gonna get you close to 50 bucks.

what ever you do, DO NOT OVER TIGHTEN THE CAMSHAFT BOOTS.  they break.... easily.... 

also if you replace it, you're gonna need new valve shims...
200$ bucks for a kit...
or if you're lucky and a member on here has extra that they could send to you.

but seriously. its not burnt. think of the white stuff as "ash" from a fire. you have charcoal, and then you have ash. you getting where im going with that?

I agree. That valve looks a good colour to me. I am more concerned with the other exhaust valve. It, and the whole chamber, look too dark and "wet" to me. As the head is off, it would be silly not to clean up the valves anyway but you need to find out why the other cylinder is so dark and sooty looking. It may be running far too rich on that cylinder but it appears to look more like oil than fuel deposits to me. Has it been using oil? I don't remember if you mentioned that in earlier posts.

Macka

Prior to removal I measured the shim spacing. The intakes are at .04mm and the exhaust are less then .04 so it will need a valve adjustment. Ever since i touched the carbs this bike ran like crap. Now that it is lean and not burnt even though that what i was told... I will bring my head to a motorcycle shop and have them to the 3 angle valve job and resurface the head. Also once i install the head I will have them also rejet and do a valve adjustment. The shop I'm using is http://www.billbune.com/services.html. What service would the 3 angle be?

Thanks for the help

http://www.billbune.com/services.html#FourCycleHeadWork

The 4 valve standard, and you add the 3 angle below it in the next block. I think.

Cool.
Buddha.

Quote from: MNgs500 on October 22, 2014, 07:37:03 PM
Prior to removal I measured the shim spacing. The intakes are at .04mm and the exhaust are less then .04 so it will need a valve adjustment. Ever since i touched the carbs this bike ran like crap. Now that it is lean and not burnt even though that what i was told... I will bring my head to a motorcycle shop and have them to the 3 angle valve job and resurface the head. Also once i install the head I will have them also rejet and do a valve adjustment. The shop I'm using is http://www.billbune.com/services.html. What service would the 3 angle be?

Thanks for the help

Your valve clearance being under .04 isn't a problem, you have to be closer to .01 or so before you'd have to worry. Valve adjustments are related more to miles run since last check, oil grade and how much rpm you had (Too much idling is bad, steady mid rpm runs in the correct gear are better) etc etc.
Your carbs may not have even been that far off. Your white and ashy valve probably looks like 90% of stock bikes. How did the plugs look ?
I said right when you put the pic of the thing form the back side, tha tvalve is fine, just a hair lean. You didn't have to pull it apart.
Cool.
Buddha.

A 3 angle valve grind?  A GS500 is not rocket science, it's more like tractor science!  Valves look OK to me, I'd pull it apart, clean carbon, and lap valves.  If a quick lap shows good seal on all valves put it back together and enjoy it some more.  If you grind valves and seats you'll be limiting future valve adjustment range.

That's what I did on my 02 GS when a sticking bucket caused a broken exhaust valve.  I replaced the broken one, lapped them all to check seal, cleaned carbon, and put it back together.  Now years later no further engine work it still runs like new and a comprssion check this spring at 100k miles showed 140 psi on both cylinders.

Did you check compression before you pulled the head? 

Quote from: gsJack on October 23, 2014, 06:06:28 AM
A 3 angle valve grind?  A GS500 is not rocket science, it's more like tractor science!  Valves look OK to me, I'd pull it apart, clean carbon, and lap valves.  If a quick lap shows good seal on all valves put it back together and enjoy it some more.  If you grind valves and seats you'll be limiting future valve adjustment range.

Not really. If you lap it - you could lose adjustment range. But a skilled motorcycle machine shop - or even a car shop, will be easily able to surface the top of the valve stem and get you back right into the middle of the adjustment range.

Cool.
Buddha.

A quick lap to check seal won't take enough off to measure, just changes color so you can see if seal is good.  Not talking about grinding valves with lapping compound.   

Works for me and price is right.