Help for a new couple?? Sorry kinda long

[donkris]

Yesterday I pulled the carbs again and soaked them overnight. I cleaned everything until it's all shiney. I also rechecked the float height, all looks good. I won't get the new petcock until Wednesday or Thursday, I hope.[-o< I put it back together today and it started right away with full choke. After about five minutes I took the choke off and it idled at about 1300. Then after about another five minutes it started to increase to just under 3000, stayed there for about a minute, then the idle came back down to about 1300. It did this without me touching it. Then after about fifteen of running it just died. Would not start even with the choke on full. I let it sit for about fifteen minutes and it starts again, even without choke. But then after idling for a few minutes it dies again. It seems like it simply won't run after it gets hot. What could it be??

I did pull the bowls off #1 and #4 to see what the fuel level looked like. Both were about 3/4 full. Does that sound right? Seems a little high to me but I don't know how much should be in those. I pulled the right after the bike died the second time. Any help is greatly appreciated. Sorry for the long post.

[Schweisshund]

sounds like carbs need to be sycned

[donkris]

I thought I had it!!

I did some checking today and discovered that my fuel supply line was kinked. I thought " could it be so simple!?" So I re-routed it so there are no kinks. Hit the starter and the bike fired right away. It ran much smoother than before. I was sooooo happy. Got the idle set to 1100 and as it got warm it idled pretty steady, fluctuating about 100 rpm or so. I let it idle for about a half an hour and all was well. BUT THEN, the idle started to go up again. This time it only went up to about 2000 and stayed there. So i brought it back down to 1100. It idled there for a few more minutes and then it started to drop until it died. This was after running for about 35 minutes. That's the longest I've been able to keep it running so far. Once it died it was again hard to start. Wait about fifteen minutes and it starts and idles fine for another few minutes and dies again. I know some here have said to adjust the valves which I have not done yet 'cause I really don't know how. I've done a search but haven't found anything that's detailed enough. Can someone point me in the right direction please??
Here's what I'm thinking on the valves based on my knowledge of cars, please tell me if I'm on the right track: if the valve tolerances are off the motor can still run when cold and as the engine warms and metals expand the valves may no longer be within specs causing the cylinder(s) to lose compression and the engine dies. Same lack of compression due to valves not closing properly would cause hard starting until engine cools enough for the metals to contract.. Does this make sense??
Lastly, are shims required to adjust valves on this bike? It's a 1981 GS550T. Thanks guys.

[donkris]

Since I don't yet know how to adjust the valves, I decided to do a dry compression test. Here's the numbers:

#1 -- 122 plug is black with dry soot
#2 -- 125 plug is black with dry soot
#3 -- 100 plug is black with dry soot
#4 -- 125 plug is light tan

No oil on any of the plugs but I did discover that the head gasket is leaking oil right below the #1 cylinder. Guess I'll be ordering some parts ie every gasket that i can find. What do you guys think of these compression #s.

[goodscout]

I was getting my gs 300l running after 12 years. I took my petcock off and cleaned it and messed up the "spring" inside but didn't realize it. It ran better but still rough after cleaning the carbs. I took the petcock back off and realized I had messed it up. Ordered a new one and it runs like a new bike now. So if the kit doesn't work......couldn't believe it wasn't the carbs.

Good Luck

[jimcor]

I hope you had a big cooling fan blowing on the engine while it sat and idled for a half an hour. Those engines are designed to have airflow around the fins to dissipate heat. You seriously overcooked the head if you did not. One half hour is MUCH TOO LONG.

Change the oil you fried it.

[KEITH KRAUSE]

I put it back together today and it started right away with full choke. After about five minutes I took the choke off and it idled at about 1300. Then after about another five minutes it started to increase to just under 3000, stayed there for about a minute, then the idle came back down to about 1300. It did this without me touching it. Then after about fifteen of running it just died. Would not start even with the choke on full. I let it sit for about fifteen minutes and it starts again, even without choke. But then after idling for a few minutes it dies again. It seems like it simply won't run after it gets hot. What could it be??

I haven't read all the replies, just this one.
Sounds like either poor venting or both poor venting and intake leak.
Be sure the gas cap venting is clear. Clean/spray the whole assembly well.
Be sure the vacuum line to number 2 carb is in good condition/not kinked.
Be sure the floatbowl vent lines are breathing clear and not kinked. Test by blowing into them.
I suggest a clear fuel line. Watch the fuel flow if the problem starts again after checking the above and starting again.
If flow looks good with no bubbling/frothing, etc, and it still attempts to stall/stalls after warming up, remove the gas cap if any doubt how well you cleaned it before it stalls to see if that helps.
After all the above, I'd focus on intake leaks.

One other thing, have you played with the mixture screws? Where are they set at now?

[donkris]

I've checked for intake leaks with the bike running using WD-40 and found none. The intake o-rings were replaced when I did the carbs. I've cleaned the gas cap and I can hear it venting air with the bike sitting in direct sunlight. I did have a large box fan on it when I let it idle for those thirty minutes. Does anybody have tips on how to adjust the valves on this bike. 81 GS550T. I'm getting a manual but it hasn't come in yet. Any help is greatly appreciated. Oh and the mixture screws are 2 turns out. Dry compression #s are posted a couple of posts back. Any comment on those? I'll get wet #s today and post those later.

[Clone]

You need to check the fuel level in the bowls, it can be done with clear fuel line attached to the drains then run up beside the carb body. Just from an idle you cannot diagnose all carb problems.
The compression numbers are close enough for comfort, did you check them with all the plugs out and the throttle locked wide open?
If yours is a 16V, checking the valves is really easy, never done a shim and bucket engine so can't speak for those. Down load a manual from the online club, I cannot remember the exact link, http://repairmanuals.com/index.html

When you dipped the carbs did you remove all the orings?

[donkris]

Good News!!!

It's running!! I can't believe it finally runs!! After all this time pulling my hair out you guys won't believe this. OK while trying to get this thing to run halfway decent I noticed some oil weeping from the head gasket. Today I decided to pull the valve cover and take a look just to see what lives in there, never been inside a motorcyce. While in there I decided to put a wrench on the head bolts, just to check. The first one I checked was barely snug! So I proceeded to check them all. Out of all the head bolts only two felt tight. I tourqued them all down and went back and checked all of them again. I put the valve cover back on and tried to start the motor. It fired up with only a touch of the button! I didn't even use the choke. It sounded like it was missing so I pulled the plugs and cleaned the soot off. I started it again and it idled much better and stayed right at 1100 rpm. I then used the highest idle method to set the mixture screws and now the idle is rock steady. It still starts with just a bump of the button. I even got to ride it for the first time today. Remember this is my first bike, so it was a little scary. I need a lot of practice. I'll get there. I just wanted to thank all of you for you patience with a new guy and for all the inputs and suggestions. I've still got a bit of work to do but at least she's running. Could not have done it without you guys. Now on to the fine tuning!!!

[jimcor]

It's running!! I can't believe it finally runs!! After all this time pulling my hair out you guys won't believe this. OK while trying to get this thing to run halfway decent I noticed some oil weeping from the head gasket. Today I decided to pull the valve cover and take a look just to see what lives in there, never been inside a motorcyce. While in there I decided to put a wrench on the head bolts, just to check. The first one I checked was barely snug! So I proceeded to check them all. Out of all the head bolts only two felt tight. I tourqued them all down and went back and checked all of them again. I put the valve cover back on and tried to start the motor. It fired up with only a touch of the button! I didn't even use the choke. It sounded like it was missing so I pulled the plugs and cleaned the soot off. I started it again and it idled much better and stayed right at 1100 rpm. I then used the highest idle method to set the mixture screws and now the idle is rock steady. It still starts with just a bump of the button. I even got to ride it for the first time today. Remember this is my first bike, so it was a little scary. I need a lot of practice. I'll get there. I just wanted to thank all of you for you patience with a new guy and for all the inputs and suggestions. I've still got a bit of work to do but at least she's running. Could not have done it without you guys. Now on to the fine tuning!!!

That's a first. I've been hanging out here for 5 years and no one has ever mentioned head bolts that loose. Next time you're in there check the valve clearance.

[txironhead]

Congratulations! But you're not done yet!

When the manual comes in, take the valve covers off and check the torque of the head bolts. Loosen one, torque it, go to the next. Then you need to adjust the valves. You can do it with a screwdriver and box wrench, but it's much easier with an inexpensive tool available from Dennis Kirk and other online vendors. I recommend the Motion Pro brand. If you get a Suzuki brand tool it'll set you back about $50, Motion Pro is $15-20. The specs will be in the manual, along with a detailed description of the process. If nothing else it'll help your gas mileage.

Even if you learn to ride this bike well, I highly recommend you ask at your local dealership or go to the AMA (American Motorcycle Association) website and find a motorcycle safety course. If you pass the course, it counts as your driving test and all you need to do is take the written test at the DMV and you have your license. Most states have programs that provide motorcycles, too. I know guys that have been riding for 20 years come out of that class going "wow, didn't know that." Plus, it gives you a discount on your insurance. I'm planning on taking the advanced course soon, it's more in-depth on accident avoidance, wet conditions, controlled panic stopping, etc.

Again, congratulations on finding the problem, especially with a solution I never would have thought to recommend. It's always satisfying fixing your own bike, especially one as old as ours. Now if any Harley RUBs (Rich Urban Bikers) give you any grief you can say, "yeah, well, can you fix your own?"

[GS750]

It's running!! I can't believe it finally runs!! After all this time pulling my hair out you guys won't believe this. OK while trying to get this thing to run halfway decent I noticed some oil weeping from the head gasket. Today I decided to pull the valve cover and take a look just to see what lives in there, never been inside a motorcyce. While in there I decided to put a wrench on the head bolts, just to check. The first one I checked was barely snug! So I proceeded to check them all. Out of all the head bolts only two felt tight. I tourqued them all down and went back and checked all of them again. I put the valve cover back on and tried to start the motor. It fired up with only a touch of the button! I didn't even use the choke. It sounded like it was missing so I pulled the plugs and cleaned the soot off. I started it again and it idled much better and stayed right at 1100 rpm. I then used the highest idle method to set the mixture screws and now the idle is rock steady. It still starts with just a bump of the button. I even got to ride it for the first time today. Remember this is my first bike, so it was a little scary. I need a lot of practice. I'll get there. I just wanted to thank all of you for you patience with a new guy and for all the inputs and suggestions. I've still got a bit of work to do but at least she's running. Could not have done it without you guys. Now on to the fine tuning!!!

WoW! Like the others have said, I wouldnt have even thought of the headbolts, and I also just checked mine last week and found they were loose too!

My bike was running slightly rough, and it solved my rough running as well, I also found that the valves were riding and I needed to re-shim.

Look around for the shim tool because I got the proper tool (non suzuki) and it cost me AU$9 and is identical to the genuine suzuki part, except the bag it came in.

Also, the advanced rider training courses are awesome and even if you have been riding for alot of years you will almost certainly learn something that you have just taken for granted.

I've had my licence and been riding for just over 22 years and decided to do a course about 4 years ago. I learnt that steering fast on the highway isnt just a case of pointing the bike there. It taught me something that I just took for granted, and that is that to steer fast into a corner, you can actually turn the handlebars (SLIGHTLY) the opposite way to the corner (Eg: road bends to the left, and you SLIGHTLY turn the handlebars to the RIGHT), and this will actually set you up into a LEFT corner very quickly.

During, and since my course, I have used this technique many a time on the bendy roads and have found it an awesome technique for getting into the S bends REALLY FAST!


Congratulations again on your unexpected findings, and I will hopefully be able to file the info regarding your solution somewhere in my brain for reference at a later date, should the need arise again!!

[donkris]

I hope my experience helps somebody else out there with similar problems. I'm a rookie at this bike stuff but I can say that I have learned a hell of a lot in the last couple of weeks. I can now get my carbs off in about five minutes! I'll continue to work on fine tuning it and practice riding as much as I can. I'm an Air Force guy so I'm required to take the Motorcycle Safety Foundation riders course before I can even drive on the base. It does count as the drivers test and it's free for military. But of course there's a waiting list, only about a month though. In the mean time I'll practice on the deserted back roads in my area, lot's of those around here. Thanks again for all the help. I'll consider this post closed and I'll be starting new ones when the need arises. Ride safe!!

[MelodicMetalGod]

Congrats on catching the ghost in the machine! Like others have said, I've never seen the head bolts listed as a possible solution for idling issues, but I guess it makes sense. Well done!

Learn to ride safely and enjoy the riding!