Hello all,

First time poster here (and as you can probably guess, first bike owner). My GS500 got left with prime on for 4-5 hours (admittedly this was pretty stupid). Went out to start the bike and it obviously didn't run. Pretty sure I've hydrolocked it as my oil smells slightly like gas. I've done a a lot of reading online mostly on these forums on the process to go through now (congrats on what seems like a really great community you guys have here). I'm going to pull the plugs, ground them to some metal on the frame, start bike normally with plugs removed, change oil etc. But I do have a couple questions that I just haven't seemed to find the answers to online. First; I've seen mention of the airbox filling with fuel when this happens. Should I check this? and if so, does that mean I need to pull the gas tank and potentially clean the air filter?

Also wondering if I should change the oil before or after turning the bike over with the plugs removed?

Anyway thanks in advance for any help you guys may offer. Apologize if these questions seem a bit simplistic. Please let me know if I am missing anything in regards to the overall process.

Thanks

Welcome to the site Ethan!

Do not, I repeat, do NOT pull the spark plugs out from the head and then connect them to the spark plug boots! With the plugs out, you can spin the engine over and raw gasoline gets launched out of the spark plug holes..... add a little spark and you have a helluva fire (yes..... I've done that!). So place a dry rag over each plug hole before cranking it over - prevents gas from getting all over, including your eyes.

After getting gas out of the cylinders, then change your oil & oil filter.

What big rich said.

And I don't think you hydrolocked. That breaks things. I think you just flooded, which will only happen when you also have leaking float needles. So be sure to check that too.

Jos

Quote from: mr72 on October 04, 2016, 08:15:08 PM
What big rich said.

And I don't think you hydrolocked. That breaks things. I think you just flooded, which will only happen when you also have leaking float needles. So be sure to check that too.

If the engine cylinders completely filled with gas due to the bike being left on prime, that would technically be hydrolocked and without the engine running, it wouldn't really break anything. But I'm not certain that's likely or even possible from the bike just being left on prime....

OP, did the wngine turn over when you attempted to start it? If not, then you could be hydrolocked. If it turns over, just didn't start, then its just flooded.

Quote from: qcbaker on October 05, 2016, 08:12:27 AM

If the engine cylinders completely filled with gas due to the bike being left on prime, that would technically be hydrolocked and without the engine running, it wouldn't really break anything. But I'm not certain that's likely or even possible from the bike just being left on prime....

Well, I think technically if the cylinders had a greater volume of liquid fuel in them than the combustion chamber volume, then it would be hydrolocked. If you turned the starter with it in this condition on the compression stroke (exhaust valve closed, piston rising) then something would break. Starter, connecting rod, wrist pin, a bearing, etc. My guess is the weakest link is the starter, and it would either break or it would just only turn like 90 degrees and then stop turning as if the battery was dead.

I agree, I am also not sure it would be possible at all to get the engine hydrolocked like this by leaving the petcock on prime, so it's far more likely is it is just flooded due to being left on prime AND leaking float needles. So while it was left on prime the float bowls got overfilled and when you attempted to start it way too much fuel was pulled into the cylinders and fouled the plugs etc., but this is not nearly enough to hydrolock the engine. If the starter turns all the way around and you have compression (that is, you didn't break something with the starter), then it was not hydrolocked.

Flooded is entirely possible and likely. Happened to me a few times. The solution for me was to use the drain screws on the bottom of the carbs to drain the excess fuel from the carb bowls (put a small container under them first, like the lid from a water bottle or something) and then pull the plugs and crank the engine for a little bit with the throttle wide open. Once drips of fuel are no longer being spit out the plug hole, put the cleaned/gapped plugs back in and fire it up. Should start normally.

But the key is if this happened, then your float needles likely need to be replaced. And while you have the carbs apart, it's a great time to replace other o-rings and replace the pilot jets which might be gunked up. Fun times!

Before you start it squirt some oil down the spark plug holes also, you don't wanna wash the cylinder walls from the potential excess fuel.

I will tell you exactly what happens when you try to START a hydrolocked GS5.........absolutely nothing! The starter motor develops nowhere near enough power/torque to damage anything.

If however you were to suddenly ingest a large amount of water with the engine running it would be a different matter.

Quote from: sledge on October 05, 2016, 10:38:50 AM
I will tell you exactly what happens when you try to START a hydrolocked GS5.........absolutely nothing! The starter motor develops nowhere near enough power/torque to damage anything.

Thanks for clarifying that

I figured as much. You can bend or break things in some small engines when they are hydrolocked using the mechanical start mechanisms, such as a weed eater and a pull cord. Didn't know if that was the case with the GS. Good to know.

Carry on

Wow guys, thaks for all the reply's!
This has given me a lot of hope that the bike is going to be ok.
I'm not going to try and multi-quote all these posts but I'll try to answer all of you the best I can.

:

Quote from: Big Rich on October 04, 2016, 01:31:50 PM

Big Rich I'll definitely keep the holes covered with a towel. Are you suggesting to not ground the plugs and instead just keep the caps separate?

Quote from: qcbaker on October 05, 2016, 08:12:27 AM
Jos

Quote from: mr72 on October 04, 2016, 08:15:08 PM
What big rich said.

And I don't think you hydrolocked. That breaks things. I think you just flooded, which will only happen when you also have leaking float needles. So be sure to check that too.

If the engine cylinders completely filled with gas due to the bike being left on prime, that would technically be hydrolocked and without the engine running, it wouldn't really break anything. But I'm not certain that's likely or even possible from the bike just being left on prime....

OP, did the wngine turn over when you attempted to start it? If not, then you could be hydrolocked. If it turns over, just didn't start, then its just flooded.

It depends on how you defined turn over but yes the starter turned over once and than just stopped, at first I figured this was normal since the bike was cold, when I engaged it again all it did was click. IE did not turn over at all. What causes me to assume it hydrolocked was the fact that my oil smells somewhat like gas. Could that happen in a flood as well? or am I right to assume that it is a pretty clear sign of hydrolock.

Quote from: mr72 on October 05, 2016, 08:36:34 AM

Quote from: qcbaker on October 05, 2016, 08:12:27 AM

If the engine cylinders completely filled with gas due to the bike being left on prime, that would technically be hydrolocked and without the engine running, it wouldn't really break anything. But I'm not certain that's likely or even possible from the bike just being left on prime....

Well, I think technically if the cylinders had a greater volume of liquid fuel in them than the combustion chamber volume, then it would be hydrolocked. If you turned the starter with it in this condition on the compression stroke (exhaust valve closed, piston rising) then something would break. Starter, connecting rod, wrist pin, a bearing, etc. My guess is the weakest link is the starter, and it would either break or it would just only turn like 90 degrees and then stop turning as if the battery was dead.

I agree, I am also not sure it would be possible at all to get the engine hydrolocked like this by leaving the petcock on prime, so it's far more likely is it is just flooded due to being left on prime AND leaking float needles. So while it was left on prime the float bowls got overfilled and when you attempted to start it way too much fuel was pulled into the cylinders and fouled the plugs etc., but this is not nearly enough to hydrolock the engine. If the starter turns all the way around and you have compression (that is, you didn't break something with the starter), then it was not hydrolocked.

Flooded is entirely possible and likely. Happened to me a few times. The solution for me was to use the drain screws on the bottom of the carbs to drain the excess fuel from the carb bowls (put a small container under them first, like the lid from a water bottle or something) and then pull the plugs and crank the engine for a little bit with the throttle wide open. Once drips of fuel are no longer being spit out the plug hole, put the cleaned/gapped plugs back in and fire it up. Should start normally.

But the key is if this happened, then your float needles likely need to be replaced. And while you have the carbs apart, it's a great time to replace other o-rings and replace the pilot jets which might be gunked up. Fun times!

I think you actually just answered my previous question with this post. Anyway, please forgive my ignorance but to check the float needles does that I mean I need to pull the carbs? What you briefly outlined sounds like a pretty involved process and as you put mentioned I'd want to do all the other carb maintenance so I wouldn't have to pull them twice. While I definitely want to do that, and I bought this as a project bike ($400....yeah baby), with cold weather approaching, and me in the thick of college midterms this is a process I'd rather go through around christmas time when I am not going to want to be riding the bike, and I actually have time to read up on this stuff so I can kinda know what I'm doing. Understand if it can't/shouldn't wait but just wondering if I have a bit of leeway.

Quote from: vagabonder on October 05, 2016, 12:29:59 PM
Big Rich I'll definitely keep the holes covered with a towel. Are you suggesting to not ground the plugs and instead just keep the caps separate?

I'm no Big Rich but I'll answer here anyway. What he means is to pull the plugs out and set them aside somewhere safe, like on the bench. Then leave the spark plug boots flapping in the breeze when you turn over (or attempt to turn over) the engine.

Quote
It depends on how you defined turn over but yes the starter turned over once and than just stopped, at first I figured this was normal since the bike was cold, when I engaged it again all it did was click. IE did not turn over at all. What causes me to assume it hydrolocked

I think you are right. It is hydrolocked. Which means there's a really bad float needle leak, and most likely you are going to wind up flooding the engine anyway even without leaving it on prime.

Here's what I think happened: there was some liquid fuel in at least one cylinder, you turned the starter, it pushed the piston towards TDC and then the starter stalled when the piston hit the "wall of fuel". With any luck the starter is not strong enough to bend/break anything. If you pull the plugs and turn the starter it should turn and spit fuel. Put a shop towel in the plug hole loosely to prevent fuel from getting everywhere.

Quote
to check the float needles does that I mean I need to pull the carbs?

Yeah. I would buy a whole set of o-rings, you can find the here:
http://www.thisoldtractor.com/for_sale_dr350_orings.html

You need two of each:

09280-40010 intake manifold o-rings
13295-29900 pilot air/fuel mixture screw (needle) o-ring (get Viton)
13374-35C00 float valve seat (get Viton)
13374-46710 float inlet (get Viton)

I'd also check and make sure the "little o-rings" that seal the vacuum ports on top of the carbs are still there (they tend to go missing) and make sure the caps on those vacuum ports are secure.

And you will need a new set of float needles. You can find those on ebay all day long, like $11 IIRC.

If it was me, I'd also get a pair of size 40 pilot jets at least to replace them because I don't trust cleaning the old ones. Those little orifices are only 0.375 or 0.4 mm so it doesn't take much to clog them.

You will have to pull the carbs and take the float bowls off to change all of this stuff. It's not hard. Hit the gstwins wiki and it has a walk thru. It really is not difficult if you are patient and meticulous, follow the instructions to a "T" and ask for help when you get stuck. Not a big deal. And it's very empowering to know you can work on it, so if it doesn't run right after, you can feel better about attacking whatever else is left to fix.

If I were you I would do this before you go ride this bike. I thought I had mine nailed and it had a leaking float needle and left me stranded at a gas station, I had to walk home. Sounds like yours is even worse. Prime or not, it may flood and leave you stranded. Bite the bullet. It's like $30 worth of parts and a lot of peace of mind.

IMHO

There's good help here on gstwins.

Yep, Mr72 beat me to it. There's no reason to have the spark plugs in the boots when pumping out the cylinders. The safest thing would be to have the kill switch in the off posiyion, so absolutely no spark would be created anywhere.

Quote from: mr72 on October 05, 2016, 01:43:45 PM

Quote from: vagabonder on October 05, 2016, 12:29:59 PM
Big Rich I'll definitely keep the holes covered with a towel. Are you suggesting to not ground the plugs and instead just keep the caps separate?

I'm no Big Rich but I'll answer here anyway. What he means is to pull the plugs out and set them aside somewhere safe, like on the bench. Then leave the spark plug boots flapping in the breeze when you turn over (or attempt to turn over) the engine.

Quote
It depends on how you defined turn over but yes the starter turned over once and than just stopped, at first I figured this was normal since the bike was cold, when I engaged it again all it did was click. IE did not turn over at all. What causes me to assume it hydrolocked

I think you are right. It is hydrolocked. Which means there's a really bad float needle leak, and most likely you are going to wind up flooding the engine anyway even without leaving it on prime.

Here's what I think happened: there was some liquid fuel in at least one cylinder, you turned the starter, it pushed the piston towards TDC and then the starter stalled when the piston hit the "wall of fuel". With any luck the starter is not strong enough to bend/break anything. If you pull the plugs and turn the starter it should turn and spit fuel. Put a shop towel in the plug hole loosely to prevent fuel from getting everywhere.

Quote
to check the float needles does that I mean I need to pull the carbs?

Yeah. I would buy a whole set of o-rings, you can find the here:
http://www.thisoldtractor.com/for_sale_dr350_orings.html

You need two of each:

09280-40010 intake manifold o-rings
13295-29900 pilot air/fuel mixture screw (needle) o-ring (get Viton)
13374-35C00 float valve seat (get Viton)
13374-46710 float inlet (get Viton)

I'd also check and make sure the "little o-rings" that seal the vacuum ports on top of the carbs are still there (they tend to go missing) and make sure the caps on those vacuum ports are secure.

And you will need a new set of float needles. You can find those on ebay all day long, like $11 IIRC.

If it was me, I'd also get a pair of size 40 pilot jets at least to replace them because I don't trust cleaning the old ones. Those little orifices are only 0.375 or 0.4 mm so it doesn't take much to clog them.

You will have to pull the carbs and take the float bowls off to change all of this stuff. It's not hard. Hit the gstwins wiki and it has a walk thru. It really is not difficult if you are patient and meticulous, follow the instructions to a "T" and ask for help when you get stuck. Not a big deal. And it's very empowering to know you can work on it, so if it doesn't run right after, you can feel better about attacking whatever else is left to fix.

If I were you I would do this before you go ride this bike. I thought I had mine nailed and it had a leaking float needle and left me stranded at a gas station, I had to walk home. Sounds like yours is even worse. Prime or not, it may flood and leave you stranded. Bite the bullet. It's like $30 worth of parts and a lot of peace of mind.

IMHO

There's good help here on gstwins.

Cool, thanks for all your help. If I do this, is there anything else I should check/modify while I have the bike essentially taken apart? Would rather not put it back together again and than realize I want/need to do something else, so if I can kill a couple birds with one stone that'd be awesome. Secondly, I apologize if I'm rewinding the conversation but I do want to double check on this. Even though the bike has run fine when the fuel line is in the on/res position, the float needle is still very likely to be a problem in the future? It couldn't have just been the unhindered flow of gasoline from being on PRI for an extended period of time that caused fuel to work it's way through the components and flood/lock the engine?

Regardless, your part about the empowerment aspect actually really resonated with me. What I would love to get out of all of this is an education, and a sense of satisfaction and ownership (As corny as that sounds I actually do mean it). I already have this from a cosmetic angle (the bike currently has a bit of a streetfighter look that's likely to upset the purists...sorry guys) but I have yet to take on the innards of the bike. The downside is that I really wanted to enjoy the nice weather and get the bike on the road. We'll see what happens, I'll definitely put in an order for the orings (thanks for that resource btw) and see if I can't squeeze in some time between midterms to work on the bike. As it is I've got a pair of dual headlights that are currently installed but not wired to the bike. I'll actually probably making a post asking for help with that very soon.

There's an endless amount of "while you're in there" that can keep you from ever getting anything finished

Many here may think my o-ring replacement strategy is overkill, so I think you probably will be covering the "while you're in there" with the o-ring replacement.

BTW, even though I recommend replacing the pilot adjust screw/needle o-rings, there is a sort of special set of skills required. First you want to turn them all the way in until they stop (don't tighten hard ... just until they stop turning easily) and COUNT THE TURNS. Work on only one carb at a time. Then when you pull out the needle, MAKE SURE you get the spring, washer, AND THE OLD O-RING out. To get the washer and/or o-ring you might need to make a tool, like take a piece of thin (24AWG) bare wire and bend it into an "L" shape that will fit into the hole, then you can use this to kind of "pick" the old o-ring out of the hole. Then when you put the new o-ring on, stack up the spring, washer, o-ring in that order on the needle and put it back in, tightening all the way like before and then back it out the same number of turns (EXACTLY ... like if it's 2 3/4 turns, then do that) so the carbs will have the idle mixture adjusted the same when you put it back together as they were when you pulled it apart.

If that sounds like too much, you might get away with not swapping that o-ring. The others are way easier to do. And you CAN swap these o-rings later with the carbs on the bike, it's just way easier to get the old ones out with the carbs on the bench.

Now as far as riding it as-is before you can work on it, well if it was me I wouldn't. But I am in no great rush to go ride. The float needle is supposed to seal against the seat and prevent excess fuel from flowing into the float bowl. When the floats are "up", that is the float bowl is "full", then the needle is pushed into the seat and it is supposed to seal, preventing fuel from flowing. If it doesn't seal, then fuel will flow in even if the float bowls are "full" and it will flood. The reason it doesn't flood while parked when the petcock is on RUN is because the petcock prevents fuel from flowing, but when there is vacuum the petcock is open and it still can flood while the bike is running. Run it long enough on low rpms and light throttle or at idle or down the right hill and it may flood while it's running, or it may wind up in a flooded state when you park and refuse to start again.

It probably won't die while running but it may refuse to start after you park it for a short time, like mine did at the gas pump when it was doing the same thing. Up to you, roll the dice? Maybe it floods again? Maybe not? It's kind of a risk, who knows. No way to know for sure until it happens, or not Like I say, if it was me I'd go grab some float needles locally or Amazon-Prime them in 2 days and replace them along with the o-rings, but I don't have the same kind of time constraints as you. I ordinarily can't afford to get stranded.