So.. My spark plugs, fun fun fun. Anyways. I had a question for you all. Today I did a test, I pulled my spark plugs, and switched them to the opposing side. No change in start up. Now here's my question. If you pull the right coil away from the plug, would the left side start?
Because I Pulled the right coil from the right, and tried to start it over, it wasn't firing, now than I plugged the right back in and pulled the left coil and it fired over. So coils bad? Piston Derped? Spark plug bad? could be why there's been my "popping issue" its misfiring and that's what is popping. or the reason my engine has been getting hot.. piston is stuck or something and I've been running on 1 cylinder sense I got the bike... I don't know the difference first bike I ever rode..
GStwin gods, I call forth you. Tell me whats wrong?
Sounds like you may be running on one cylinder. Start the bike and let it run. Pull off one spark plug boot and it should run rough but continue running on the other cylinder. Repeat for the opposite side. If the bike dies when you pull one side's plug off, the other cylinder is not working (i.e. you are only running on the one cylinder you unplugged). Then you have to determine if it is a spark or fuel issue. If you have a spare good spark plug (doesn't have to be a GS plug), plug it into the boot and hold the tip up to the engine whileyou run the starter. You should see a blue arc jump across the gap. If you don't have a spare good plug, use the plug from the working cylinder to test. If you don't have spark, then it may be a coil issue. If you have good spark it is probably a fuel issue (probable clogged jet).
-Jessie
I know 1000%%%%% its not a fuel issue... I know. because I've cleaned them carbs to where they cannot be cleaned any more!!! so ima go for, its the cylinder and spark issue.. God this whole time I thought it was the carbs.. but it was my engine.. SILLY ME! :D okay so what baltimoreGS said sorta answered my question, IT should run only on 1 cylinder... no matter the side. so.. is the spark plug bad, or the coil.. WE shall find out.
Hopefully it is something simple like a bad plug but those aren't the only possibilities. You can have fuel and spark but the cylinder still won't do anything if it doesn't have compression. Start by checking for spark issues since it is the most likely cause (Accom's razor). If it isn't a spark issue, then do a compression test. If you don't have good compression start looking at the valves. If you do have compression, go back to the carbs. Good luck! :thumb:
-Jessie
well, I did switch the plugs, one side from another, so that means Coils/compression? is there a fix for the coils? or do I just have to get whole new ones?
You don't fix coils if they are bad, just replace them. I'm sure adidasguy has a good used coil in his stash if that turns out to be your problem. Your first step is to check for spark. If you find it is a spark issue, swap the coils side to side to make sure they are the problem. If the coil is bad your engine should now only run on the opposite side cylinder. At that point you are safe to spend money on a coil. If the bike still only runs on the same cylinder you have eliminated the coil as a problem. Then you get into the pick ups and other areas that are part of spark. Let's not get too complicated yet, just check for spark and go from there ;)
-Jessie
Almost like Trey - and that was spark plug.
But try this - the side it won't start on. What about with full choke?
Try swapping coils. Check for good connections to the coils.
Sure you swapped plugs?
(Yes, I do have a pile of coils)
I'm sure I swapped plugs, one was PERFECT looking, other one was "wet" Rich looking perfect. left side, good side. Wet right side, bad side. Tried full choke, still wouldn't turn over. no choke, half, full, nadda. I'm not sure how to swap coils, gotta take the gas tank off by my view don't you? LOL... I'ma buy new spark plugs just in case anyhow.. doesn't matter wont kill me. Ill check the swapped plugs right now.. Wait for details.
With long and angle tools, you can remove the coils without removing the tank. I did that on Trey before I really got into him.
Go slow. Take your time and it can be done.
its fine, took the tank off, don't have those tools.. Better safe than sorry. Swapped the coils, Its not the coils... :/ God more and more I get into this the more and more I Think it might be serious... So. coils/spark plugs both fine.. IDk how to check compression without one of them fancy tools.. And im sure thumb over hole doesn't work.. lol
Thumb over hole, Thumb 1 hole 0, ITS COMPRESSION!!!!!!!!!!!!
okay, now how do I fix it? Lol...
I'm having the same problem with PITA. Although, I don't believe mine is a compression issue.
Quote from: shonole on January 19, 2012, 01:20:33 PM
I'm having the same problem with PITA. Although, I don't believe mine is a compression issue.
Yeah? Maybe we can work together and figure this out.. Cause Idk if when you put your thumb over the spark plug hole, if its suppose to Suck in or blow out.. cause when I did. my finger was being blown out with little pressure, but with full body weight on arm pressure it started to sorta suck in.. I figure that's compression.
You need a compression gauge with a 12mm fitting to check compression. If you felt no pressure blowing out then I would say it is compression but other than that your thumb test is fairly worthless. If you get poor or no reading on a compression gauge, then you have to figure out why there is no compression. Start by checking the valves. I would expect you'd find there is insufficient clearance on one valve and the valve is hanging open. If you can't spin the valve shim bucket, it is stuck open. Hopefully the bike hasn't been ridden much like that or you may have burned a valve. But that is worse case scenario, don't even worry about that until you find if it is a compression problem.
-Jessie
Edit: Text moved below....
Quote from: BaltimoreGS on January 19, 2012, 01:28:36 PM
You need a compression gauge with a 12mm fitting to check compression. If you felt no pressure blowing out then I would say it is compression but other than that your thumb test is fairly worthless. If you get poor or no reading on a compression gauge, then you have to figure out why there is no compression. Start by checking the valves. I would expect you'd find there is insufficient clearance on one valve and the valve is hanging open. If you can't spin the valve shim bucket, it is stuck open. Hopefully the bike hasn't been ridden much like that or you may have burned a valve. But that is worse case scenario, don't even worry about that until you find if it is a compression problem.
-Jessie
I can 100% say, its been ridden with this problem a whole lot... sadly..... but if not spark, not coil, not carbs. WTH? Has to be compression! Not saying your wrong or anything just I really wanna go on that trip this upcoming month.. and its like frustrating to not know at lease wth is wrong.
PO left his address on some things he gave me.. might pay him a visit... maybe take him camping...?
You can borrow a compression tester from advance, auto zone or pep boys. Go and ask for one to use. You have to pay for the item in deposit, but when you take it back, they credit all the money back hoping you will now buy parts from them.
Compression Test 101
Remove both spark plugs
Screw in gauge
Hold throttle wide open
Run starter motor until needle quits going up
Repeat for other side
Around 150 psi is what I would expect to see on a decent engine. More important is balance between the cylinders. A 10% variance is allowed between readings.
Quote from: J_Walker on January 19, 2012, 01:23:08 PM
Quote from: shonole on January 19, 2012, 01:20:33 PM
I'm having the same problem with PITA. Although, I don't believe mine is a compression issue.
Yeah? Maybe we can work together and figure this out.. Cause Idk if when you put your thumb over the spark plug hole, if its suppose to Suck in or blow out.. cause when I did. my finger was being blown out with little pressure, but with full body weight on arm pressure it started to sorta suck in.. I figure that's compression.
Yeah. Mine is on the right side. Pull the right plug, engine dies. Pull the left, works great. I've swapped coils from side to side, no luck. New spark plugs, no luck. Cleaned carbs a dozen times, no luck. Adjusted float height, no luck. (Although, I will be checking this again after my new boots get here from adidas). I don't have a compression gauge (yet), but when sticking my thumb over the empty plug cylinder, I get strong cyclical puffs of air.
I've been posting over here:
http://gstwins.com/gsboard/index.php?topic=58643.40
Quote from: BaltimoreGS on January 19, 2012, 01:44:11 PM
Around 150 psi is what I would expect to see on a decent engine. More important is balance between the cylinders. A 10% variance is allowed between readings.
OEM service manual says 142-199 normal. Low minimum compression 112psi. Maximum difference between cylinders is 28psi.
Engine should be warmed up. Insure all head bolts are torqued to correct value and valves are properly adjusted (paraphrasing the manual.) Remove both spark plugs. Keep throttle grip open when doing the test.
Quote from: adidasguy on January 19, 2012, 04:31:13 PM
Engine should be warmed up. Insure all head bolts are torqued to correct value and valves are properly adjusted (paraphrasing the manual.) Remove both spark plugs. Keep throttle grip open when doing the test.
Thanks Adidas, that is a bigger variance than I would have expected. I'd skip the engine warming step though since you are only seeing if there IS compression at this point. If a valve is stuck open you don't want to run it anymore than necessary.
-Jessie
I think Jessie will agree with me, but a cold compression test is useful for checking for differences between cylinders. A warm compression test will tell how bad a cylinder is out of spec.
As far as the "thumb over the spark plug hole" trick - that just tells you that the motor isn't seized and there's not a golf ball size hole in your piston. 10psi will move your finger, but not move a motorcycle......
I got in a brand new original 1990 service manual. Nice! I was just quoting the manual.
well, I don't have the tool to check the compression, really don't want one as a birthday gift either.. So i'll be taking the heads off tomorrow and checking the valves.. anything I should be looking for? Other than burnt charred nasty valves or crushed/bent/non spinning valves.
Quote from: 89500inPA on January 19, 2012, 01:38:25 PM
You can borrow a compression tester from advance, auto zone or pep boys. Go and ask for one to use. You have to pay for the item in deposit, but when you take it back, they credit all the money back hoping you will now buy parts from them.
Just in case you missed it........
Quote from: Big Rich on January 20, 2012, 01:04:30 AM
Quote from: 89500inPA on January 19, 2012, 01:38:25 PM
You can borrow a compression tester from advance, auto zone or pep boys. Go and ask for one to use. You have to pay for the item in deposit, but when you take it back, they credit all the money back hoping you will now buy parts from them.
Just in case you missed it........
Well the guy who was suppose to pay me my money, for stealing/breaking something of mine is now currently in jail for 3 days.. and I wanna figure out whats wrong before the end of this month... i'll see, but advanced auto discount near my house, are a bunch of A$$holes! long story short, they are thief's and scam artist. I'll call someone that May be able to help me. don't know if he has the tool or not..
Might just be a terminology mistake but you only need to take the cylinder head cover off to check the valves, don't take off the actual cylinder head. You'll need a decent feeler gauge ($10 or less) and basic hand tools. You don't even need the feeler gauge to make sure the valve shim buckets move. Let us know what you find.
-Jessie
Use Kerry's video - http://video.google.com/videoplay?docid=-2015554469142545363
Quote from: Big Rich on January 19, 2012, 09:45:57 PM
I think Jessie will agree with me, but a cold compression test is useful for checking for differences between cylinders. A warm compression test will tell how bad a cylinder is out of spec.
As far as the "thumb over the spark plug hole" trick - that just tells you that the motor isn't seized and there's not a golf ball size hole in your piston. 10psi will move your finger, but not move a motorcycle......
Well maybe I've made it sound too simple but the finger in the hole compression test or perhaps more aptly descriptive "thumb over the spark plug hole" trick will tell you a lot more than that. If you learn how to do it, it will tell you if you have enough compression to start and run well enough so it's a good place to start. Once you've pulled the plugs to check for spark it only takes a minute to check for adequate compression first and when you're working on an unknown engine it's a good place to start. Check compression, ignition, and then carbs. I always give mine a quick finger compression check when I change bike plugs and I've never used or felt the need to use a compression guage on my bike engines for 170k GS500 miles and a prior 230k thousand miles on 4 previous Hondas.
Now, as far as checking spark by putting a loose plug in the plug cap and holding it against the cylinder head that too is just a good starting point in checking for ignition but it will not tell you if that plug is firing in that engine under running compression. At some compression pressure it will stop firing and that's how we use to check plugs before replacing, now if they pull them they just toss them and replace. Plugs are cheap compared to current shop labor rates. But this check will at least tell you that the pickups/module are making and braking the circuit to produce spark, another good starting point at least.
To be continued in next post--
My 02 GS had a too tight valve bucket (tappet) from the factory and a finger/hole compression check showed no compression in that cylinder when cold. As tight as that bucket was when cold it would start and run roughly and then quickly warm and loosen the bucket in a minute or so and the engine would then smooth out and run properly for the rest of the day. I let it go for 20k miles hoping it would wear in but it stuck too tight one freezing cold morning and broke an exhaust valve when first cranking that I had to replace. Buckets loosen and valve clearances increase as the engine warms with an aluminum head and overhead valves because the aluminum expands faster than the steel parts as the engine temps increase.
This same engine began running on one cylinder intermittently during this early 20k mile period and this was confirmed by pulling the plug wires at idle like was done above. In my case the problem turned out to be a plug wire that was loose in the coil. The coils are sold as an assembly with the spark plug wires bonded tight in place so if you have a loose plug wire it's going to be a problem. Other possibilities for the engine to be running on one cylinder that have been experienced by forum members include a bad ignition pickup, a bad spark plug even though it was a new one, or a carb problem. On a newly acquired bike the valve clearances should be checked as soon as possible although it would be rare to still have no compression on a cylinder after it's warmed due to a tight valve because the valve clearances increase a considerable amount as it warms. But a too tight exhaust valve will have a shortened life.
10 psi wont move your thumb, atleast 50 psi ... more if its got good access which a naked GS does.
Cool.
Buddha.
Where can I get valve shims? if I turn out to need them, was watching that video. Suzuki GS500 Valve Adjustment, one. also where could I buy feeler gauges?
Any decent auto parts store should have feeler gauges and possibly Sears' tool section. Harbor Freight has them too. I like to mic a new set of feeler gauges just to make sure they are accurate (especially if cheap). You can get valve shims from a local Suzuki dealer or online. I just ordered some from an online company but have not received them yet. I'll give their name if they turn out to be a good source.
Technically Kerry checks the valves with the cams in the wrong position but his way should work. Next time I have an engine open I want to check and see if the reading his way is the same as the reading doing it the way the Suzuki manual says.
-Jessie
Sorry Jack, while it may work for you i feel confident in saying it's not for everybody. The actual compression tester gives cold hard numbers. Know what I'm saying?
And sorry to you too Buddha - I'll change the expression to 50 psi next time as well.
K, I got a list of what I need for the most part, just have to find people who have the parts/stuff or the place. Trying to get a 3 shop stop with all my stuff.. Putting together a big list. been talking to Adidas, hopefully ill be able to order parts soon. Thanks for the info, Btw how is kerry's wrong? how are you suppose to do it?
Quote from: J_Walker on January 21, 2012, 02:40:39 PM
K, I got a list of what I need for the most part, just have to find people who have the parts/stuff or the place. Trying to get a 3 shop stop with all my stuff.. Putting together a big list. been talking to Adidas, hopefully ill be able to order parts soon. Thanks for the info, Btw how is kerry's wrong? how are you suppose to do it?
Before you buy anything, post your list here to see if anyone has it cheap or if you even need it at all. All you need for the valves is a feeler gauge to begin with, you don't need valve shims and a valve shim tool if everything is in spec. And even if it isn't, until you have a valve shim tool and remove and measure the old shims you will not be able to determine what size shims you need to order.
Kerry faces the cam lobes straight up when he checks the valves. Suzuki has you align the R/T mark on the rotor to orient the cams a certain way to check the valves. I have never checked to make sure the readings are the same on both methods. If you check out the first part of Adfalchius' top end rebuild video she checks the valves the way the Suzuki repair manual says to.
-Jessie
Picture for all you picture whores.
(http://i40.tinypic.com/24dromg.jpg)
Looks like it'd run?
feeler gauges, Shims, calipers, valve shim tool, whole new engine head gasket[I think that's the name], center stand, rear/front break caliper, rear break disc, new tires, rejet kit, various bolts, torque wrench,right heel guard. and some more stuff that I may have missed.. Will edit later. Seems like I need all this stuff. for now and later...