Actually it's been stated here that having the tank too high will cause issues like that. I found by hooking it on the left side handlebar it works just fine and you won't see any problems.
-
Required reading for all forum users!!!
Welcome!
Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.A note to new registrants...
All new forum registrations must be activated via email before you have full access to the forum.A Special Note about Email accounts!
DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.A note to old forum members...
I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.
Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...
-
Returning Visitors
If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.
If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.
D
D-Mac
Guest
Great to know! Will do.
G
Guest
Guest
lol on the "moron alert"... but we've all done things like that...
yes, the pressure from the fuel supply being that high would likely overcome the (minute) pressure from the carb bowl floats onto the bowl valves... hell, a faulty petcock can be enough for the carb valves to leak...
yes, the pressure from the fuel supply being that high would likely overcome the (minute) pressure from the carb bowl floats onto the bowl valves... hell, a faulty petcock can be enough for the carb valves to leak...
D
D-Mac
Guest
Yup. I'm hopeful this latest issue can be resolved easily enough. If I'm still getting evidence of flooding after lowering the aux tank and fitting new plugs, I'll pull the carbs again and re-test them on the bench for flooding and re-check float heights. The fact that fuel remains in the line right over top of the carbs when the engine is off seems to suggest the float needles are doing something right anyway.
The petcock is OEM and new, and at least it works great (tank is currently sitting on the bench 'on' and not leaking a drop - with a little vacuum pressure it opens and flows well, and it always flows freely on 'prime' as it should).
The petcock is OEM and new, and at least it works great (tank is currently sitting on the bench 'on' and not leaking a drop - with a little vacuum pressure it opens and flows well, and it always flows freely on 'prime' as it should).
D
D-Mac
Guest
Note: I'm cross-posting a similar message with photos and instructions to a thread in the carb section (more people check that one, but I want a record here as well since it's an important part of my build).
So where were we.....?
After fixing the level of my aux fuel source, I still experienced the same problems with the engine missing at idle and even under partial throttle (popping and fuel being blown back through the carbs into the air filters - especially on Carbs 1&2). I checked for ignition issues (swapped ignitor boxes with a spare I have; still need to check timing though, although it's not a points ignition). Admittedly, I started the bike on the side stand (no center stand anymore), so if the float levels were set too high, that might explain why the problem was worse on carbs 1 and 2). A leaky float seat(s) could also explain it. When I pulled the carbs, the was a lot of gas in the boots. Some plugs looked wet with gas. So it was either flooding, or ignition timing (recall that cam timing and valve clearances have been set and triple-checked; bike shows no other symptoms of either of those being wrong).
I pulled the carbs again and left them overnight with my fuel source hooked up and open. No evidence of any float seat leaks. Good.
Next, I measured a couple of float levels to confirm that I had set them right (the measurement made inside the carb between the float and the carb body - gasket removed per instructions; no pics). The measurements I checked were dead on (within 0.05mm of the center of spec = 22.4mm). Yes, I checked on both sides of each float.
After checking the floats, I rigged up a setup to check the fuel levels of the carbs (what really matters to the engine). I set the carbs in a vice on a 7-degree angle (to match the angle they are in the bike) and rigged up my fuel cell to it. I used some vacuum connectors screwed into the float bowl drains to set up the 1/4" hoses to check the fuel levels within the carbs.
Single carb hooked up.
Shows how you take a measurement (note: the photo is approximate - in the case the actual measurement is a little below what is shown - I just held the camera up to give you an idea of what I'm talking about).
Shot of how I took my measurements. Note how carbs 2 and 3 have the highest fluid levels (smaller measurements). You'll see this is my measurements below.
Shot of my testing setup.
The spec is 5.0mm +/- 1.0mm according to the table in my Suzuki manual, although the detailed procedure suggests 5.0mm +/- 0.5mm.
I took an average of 5 measurements made from the edge of the bowl to the bottom of the meniscus (there's my science-geek coming out). I'll spare you the standard deviations.....
Carb 1: 4.54
Carb 2:3.60
Carb 3: 3.75
Carb 4: 4.67
Hmmm..... looks like my floats ARE set too high - #2 and #3 especially. Consistent with rich condition and perhaps flooding? I'm going to tinker around with them sometime soon and see if I can get them close to 5.0mm. At least there is hope!
Could it be the replacement seats/float needles I bought, or maybe the old floats aren't quite as buoyant anymore?
I gotta take a break from the fumes. Pretty awful!
So where were we.....?
After fixing the level of my aux fuel source, I still experienced the same problems with the engine missing at idle and even under partial throttle (popping and fuel being blown back through the carbs into the air filters - especially on Carbs 1&2). I checked for ignition issues (swapped ignitor boxes with a spare I have; still need to check timing though, although it's not a points ignition). Admittedly, I started the bike on the side stand (no center stand anymore), so if the float levels were set too high, that might explain why the problem was worse on carbs 1 and 2). A leaky float seat(s) could also explain it. When I pulled the carbs, the was a lot of gas in the boots. Some plugs looked wet with gas. So it was either flooding, or ignition timing (recall that cam timing and valve clearances have been set and triple-checked; bike shows no other symptoms of either of those being wrong).
I pulled the carbs again and left them overnight with my fuel source hooked up and open. No evidence of any float seat leaks. Good.
Next, I measured a couple of float levels to confirm that I had set them right (the measurement made inside the carb between the float and the carb body - gasket removed per instructions; no pics). The measurements I checked were dead on (within 0.05mm of the center of spec = 22.4mm). Yes, I checked on both sides of each float.
After checking the floats, I rigged up a setup to check the fuel levels of the carbs (what really matters to the engine). I set the carbs in a vice on a 7-degree angle (to match the angle they are in the bike) and rigged up my fuel cell to it. I used some vacuum connectors screwed into the float bowl drains to set up the 1/4" hoses to check the fuel levels within the carbs.
Single carb hooked up.
Shows how you take a measurement (note: the photo is approximate - in the case the actual measurement is a little below what is shown - I just held the camera up to give you an idea of what I'm talking about).
Shot of how I took my measurements. Note how carbs 2 and 3 have the highest fluid levels (smaller measurements). You'll see this is my measurements below.
Shot of my testing setup.
The spec is 5.0mm +/- 1.0mm according to the table in my Suzuki manual, although the detailed procedure suggests 5.0mm +/- 0.5mm.
I took an average of 5 measurements made from the edge of the bowl to the bottom of the meniscus (there's my science-geek coming out). I'll spare you the standard deviations.....
Carb 1: 4.54
Carb 2:3.60
Carb 3: 3.75
Carb 4: 4.67
Hmmm..... looks like my floats ARE set too high - #2 and #3 especially. Consistent with rich condition and perhaps flooding? I'm going to tinker around with them sometime soon and see if I can get them close to 5.0mm. At least there is hope!
Could it be the replacement seats/float needles I bought, or maybe the old floats aren't quite as buoyant anymore?
I gotta take a break from the fumes. Pretty awful!
Slightly too high perhaps but not enough to explain the HUGE mixture issues you are having.
The test would be better if it was done with the engine running.
Did you check those plugs between the float bowls and the venturis?
D
D-Mac
Guest
Yeah. I would tend to agree (although my experience with tuning bikes is limited).
I did check and the plugs seem to be ok. I'll post a pic later to confirm we're talking about the same ones.
N
Nightcrawler
Guest
Wow, just wow.
The attention to detail, the time and effort. A superb bike man!
The attention to detail, the time and effort. A superb bike man!
G
Guest
Guest
D-mac, I'm no master mechanic but I agree with tkent02. Float bowls are designed as a "reserve"area for the fuel. They do not meter flow through the carb (that's the job of the jets and needle). Case in point, shut the fuel flow off while the bike is running and it will run just the same until the bowls are almost emptied.
I have not seen a situation where fuel is spit back through the carb on a bike before but HAVE seen this many times on car engines and in each and every instance, it was timing causing the issue (either electrical or mechanical due to improper cam timing setup). The plugs being wet may not be a "fuel" issue at all but the fact that the plugs are not firing properly leaving them wet when you pull them.
If it were me, I would go through the ignition and cam timing with a fine tooth comb. Suspect every part in the loop Until it checks out good. I've even seen bad plug wires create some of the strangest issues. If you had the cams out, I would pull the cover and check the cam timing as well.
Good luck. I know how frustrating these gremlins can seem.
I have not seen a situation where fuel is spit back through the carb on a bike before but HAVE seen this many times on car engines and in each and every instance, it was timing causing the issue (either electrical or mechanical due to improper cam timing setup). The plugs being wet may not be a "fuel" issue at all but the fact that the plugs are not firing properly leaving them wet when you pull them.
If it were me, I would go through the ignition and cam timing with a fine tooth comb. Suspect every part in the loop Until it checks out good. I've even seen bad plug wires create some of the strangest issues. If you had the cams out, I would pull the cover and check the cam timing as well.
Good luck. I know how frustrating these gremlins can seem.
M
mash35231
Guest
Carb parts
Carb parts
Were did you source the new jet needle and pilot jet rubber plugs from? I've been searching the web but I can't find them.
Carb parts
Were did you source the new jet needle and pilot jet rubber plugs from? I've been searching the web but I can't find them.
Depending on what bike you have (HINT - Put it in your signature block), you can still find them from Suzuki. Look at the dealer sites like www.gssuzuki.com or www.boulevardsuzuki.com.
D
DannyMotor
Guest
Just throwing this out there, as it happened to me....
How much oil in on that KnN filter?? I over-oiled mine and the bike ran TERRIBLY rich until I completely washed it out, dried it, and then BARELY misted the filter on the OUTSIDE only with oil.. just barely enough to turn it pink... now I can actually tune it.
If it's over saturated, it's not going to run right.
How much oil in on that KnN filter?? I over-oiled mine and the bike ran TERRIBLY rich until I completely washed it out, dried it, and then BARELY misted the filter on the OUTSIDE only with oil.. just barely enough to turn it pink... now I can actually tune it.
If it's over saturated, it's not going to run right.
M
mash35231
Guest
Jet needle
Jet needle
The reason I asked about the jet needle is the stock GS550LZ needle has no adjustment...only 1 c-clip groove...but the needle D.Mac had pictured is a adjustable needle with multiple c-clip grooves. I have a K&N air filter with stock exhaust and I may need to adjust the needle a little bit.
Jet needle
The reason I asked about the jet needle is the stock GS550LZ needle has no adjustment...only 1 c-clip groove...but the needle D.Mac had pictured is a adjustable needle with multiple c-clip grooves. I have a K&N air filter with stock exhaust and I may need to adjust the needle a little bit.
D
D-Mac
Guest
Adjustable needles came with the DynoJet kit I bought.
I got the plugs through Z1enterprises I think (or they might be OEM).
D
D-Mac
Guest
Thanks guys! Even when I disagree with y'all (which isn't often), it still makes me think, which almost always leads to better ideas.
I haven't had a chance to get back to the bike in a few days, and with my 'day job' starting up tomorrow it'll be at least a few more before I do.
I agree that float level settings being off just a bit wouldn't cause this (unless they are set too high and flooding - seems unlikely though). That was a case of wishful thinking. I will adjust them a bit and keep the bike more level on next start-up, just to rule out any flooding issues. I have seen both cam and ignition timing cause these kinds of problems, so they both make sense - more than what I think could be carbs alone.
I'm setting aside cam timing for now given the fact that it idled well when first started, it always starts easily, leak-down at TDC is excellent, and I did (10? 20?) re-checks I did on cam timing during the latter part of rebuild, plus photos indicate it's fine. If I do end up checking cam timing again, I promise to do it in front of at least 20 mechanics so that they can beat me silly.
!!!New thought (also leads me to think ignition timing might be the culprit). Now that I think about it (and I can't believe I didn't before), this bike did the EXACT same thing - backfiring through carbs - when I first got it and managed to start it up (I even have a video around here somewhere of it "running" back then). I had assumed it was just clogged carbs at the time, although in retrospect it didn't show any other symptoms of being clogged, and the guy I bought it from (he's an experienced vintage motorcycle mechanic I know well) had actually cleaned them before I got it. So maybe it IS an ignition problem..... If it's the same issue as when I bought the bike, that would rule out coils (now new), ignitor box (I've swapped two in and out with no difference), spark plug wires (now new). That leaves the setting of the ignition pickup/timing plate, the ignition pickup itself, and wiring to the coils (now only triggering a relay, but still potentially important).
I think I should probably check the timing with a timing gun (maybe the previous owner moved the plate too far?) and I'll probably swap in a new pick-up unit and try that too (I have a spare from my parts bike). The ignition switch is new from my rebuild, but that still leaves the ignition/kill switches and lots of wiring. Although the coils now run straight to the battery, I am still using that old wiring from to trigger my coil relay, so an issue in that wiring could still cause a fault I suppose. I could just bypass my relay completely (run coils straight to the battery with no relay) to test that out, right?
What's killing me is the fact that I don't know for certain that the carbs are OK, so I keep leaning in that direction. Your assessments are helping me see other possibilities.
Stay tuned. I might have more info by Sunday.
I haven't had a chance to get back to the bike in a few days, and with my 'day job' starting up tomorrow it'll be at least a few more before I do.
I agree that float level settings being off just a bit wouldn't cause this (unless they are set too high and flooding - seems unlikely though). That was a case of wishful thinking. I will adjust them a bit and keep the bike more level on next start-up, just to rule out any flooding issues. I have seen both cam and ignition timing cause these kinds of problems, so they both make sense - more than what I think could be carbs alone.
I'm setting aside cam timing for now given the fact that it idled well when first started, it always starts easily, leak-down at TDC is excellent, and I did (10? 20?) re-checks I did on cam timing during the latter part of rebuild, plus photos indicate it's fine. If I do end up checking cam timing again, I promise to do it in front of at least 20 mechanics so that they can beat me silly.
!!!New thought (also leads me to think ignition timing might be the culprit). Now that I think about it (and I can't believe I didn't before), this bike did the EXACT same thing - backfiring through carbs - when I first got it and managed to start it up (I even have a video around here somewhere of it "running" back then). I had assumed it was just clogged carbs at the time, although in retrospect it didn't show any other symptoms of being clogged, and the guy I bought it from (he's an experienced vintage motorcycle mechanic I know well) had actually cleaned them before I got it. So maybe it IS an ignition problem..... If it's the same issue as when I bought the bike, that would rule out coils (now new), ignitor box (I've swapped two in and out with no difference), spark plug wires (now new). That leaves the setting of the ignition pickup/timing plate, the ignition pickup itself, and wiring to the coils (now only triggering a relay, but still potentially important).
I think I should probably check the timing with a timing gun (maybe the previous owner moved the plate too far?) and I'll probably swap in a new pick-up unit and try that too (I have a spare from my parts bike). The ignition switch is new from my rebuild, but that still leaves the ignition/kill switches and lots of wiring. Although the coils now run straight to the battery, I am still using that old wiring from to trigger my coil relay, so an issue in that wiring could still cause a fault I suppose. I could just bypass my relay completely (run coils straight to the battery with no relay) to test that out, right?
What's killing me is the fact that I don't know for certain that the carbs are OK, so I keep leaning in that direction. Your assessments are helping me see other possibilities.
Stay tuned. I might have more info by Sunday.
M
mash35231
Guest
D-Mac, I'm rebuilding a 82 550L and I really like the Dime City speedo and tach that you are using. Which DC speedo matches up to the factory speedo cable and what is the tach ratio?
D
D-Mac
Guest
Here's The good news (LOL). This re-rebuild thread is NOWHERE NEAR OVER. That's right folks, I'm about to take you into new and exotic places......into the only place we haven't been on this build yet.......
Into the bottom end.
Yup. And this leads me to the bad news.....the really, really bad news.
Let's back-up a bit.
I've been thinking a lot about the problems I've been having. I kept coming back to carbs and ignition timing because both were logical. But then I started wondering what else could cause the timing to be off badly.....cam timing....maybe an electrical fault. Maybe. Then I remembered that the bike seemed to have the same problem (popping through carbs) when I first bought it, which narrows things down a lot if the cause now is the same. What HASN'T changed since then? Hmmm....
I woke up today thinking that maybe the ignition timing appears to be "off" because the pistons aren't hitting TDC at the same time. I used a dial indicator to check the piston position in cylinder #4 compared with the TDC mark. It was perfect. But when I checked cylinder #1 (which should hit TDC at the same point as #4) it was off - way off. The piston actually reaches it's highest point about 15 degrees early. Yikes!
Diagnosis? Twisted crankshaft. I'm thinking it might have resulted from hydrolock (recall that the original petcock on the bike was faulty and drained freely at all times). I caught the overflowing carbs before I started the bike, but anyone want to bet a previous owner didn't?
Soooo....now my plan of action is:
-Verify my results.
-Remove the crankshaft from my spare parts engine (with all of the work that will entail.....just getting the side covers off of that bike will be "fun")
-Main bike: Drain oil, disconnect plugs from the engine, unbolt and pull the engine from the bike, and split the cases to pull the crankshaft. Obviously, I'll swap out the various seals and check over the transmission and clutch plates/springs at the same time. Everything will get a good cleaning too. I might even end up having to re-paint the bottom end again.
Questions:
(1) I should be able to just keep the rotor on the crank and swap rotors at the same time I swap cranks, right? (maybe a good idea anyway since the one currently on my bike is chipped a little).
(2) I'll have to pull the valve cover+tensioner+at least the exhaust camshaft to get enough slack to free the crank from the cam chain on the bottom end, right?
(3) I can avoid having to pull the top end completely off my bike, right? I don't recall anything on the top-end (other than needing to free up the cam chain, above) that would require me to pull the head or cylinder block. Basically, I just don't want to risk needing another new head gasket! Related to this, I should be able to pull out the pistons from below to swap them onto the new crank, correct? (It's actually the crank they originally came from since the top-end of my main bike came from my parts bike).
Anything else to consider?
Redneck Rocket indeed.
Into the bottom end.
Yup. And this leads me to the bad news.....the really, really bad news.
Let's back-up a bit.
I've been thinking a lot about the problems I've been having. I kept coming back to carbs and ignition timing because both were logical. But then I started wondering what else could cause the timing to be off badly.....cam timing....maybe an electrical fault. Maybe. Then I remembered that the bike seemed to have the same problem (popping through carbs) when I first bought it, which narrows things down a lot if the cause now is the same. What HASN'T changed since then? Hmmm....
I woke up today thinking that maybe the ignition timing appears to be "off" because the pistons aren't hitting TDC at the same time. I used a dial indicator to check the piston position in cylinder #4 compared with the TDC mark. It was perfect. But when I checked cylinder #1 (which should hit TDC at the same point as #4) it was off - way off. The piston actually reaches it's highest point about 15 degrees early. Yikes!
Diagnosis? Twisted crankshaft. I'm thinking it might have resulted from hydrolock (recall that the original petcock on the bike was faulty and drained freely at all times). I caught the overflowing carbs before I started the bike, but anyone want to bet a previous owner didn't?
Soooo....now my plan of action is:
-Verify my results.
-Remove the crankshaft from my spare parts engine (with all of the work that will entail.....just getting the side covers off of that bike will be "fun")
-Main bike: Drain oil, disconnect plugs from the engine, unbolt and pull the engine from the bike, and split the cases to pull the crankshaft. Obviously, I'll swap out the various seals and check over the transmission and clutch plates/springs at the same time. Everything will get a good cleaning too. I might even end up having to re-paint the bottom end again.
Questions:
(1) I should be able to just keep the rotor on the crank and swap rotors at the same time I swap cranks, right? (maybe a good idea anyway since the one currently on my bike is chipped a little).
(2) I'll have to pull the valve cover+tensioner+at least the exhaust camshaft to get enough slack to free the crank from the cam chain on the bottom end, right?
(3) I can avoid having to pull the top end completely off my bike, right? I don't recall anything on the top-end (other than needing to free up the cam chain, above) that would require me to pull the head or cylinder block. Basically, I just don't want to risk needing another new head gasket! Related to this, I should be able to pull out the pistons from below to swap them onto the new crank, correct? (It's actually the crank they originally came from since the top-end of my main bike came from my parts bike).
Anything else to consider?
Redneck Rocket indeed.
eil
Forum Sage
It's a really good thing we all know you're talking about a motorcycle engine here.
Ouch!
From what I understand, hydrolocking will generally only damage an engine at speed (e.g., by suddenly sucking in a large amount of water). The starter motor doesn't have enough power to damage an engine with a cylinder full of gas. It just won't turn over. But at this point, it really doesn't matter how it happened as much as how to fix it...
I'm a newbie to this stuff, but I would think that if there was enough force to twist the crankshaft, then the connecting rods and bearings should be suspect too. You'll want to measure everything against the repair manual specs as you put it back together.
D
D-Mac
Guest
tkent02 is correct.
Bearings and rods will be swapped with the crank.
Bearings and rods will be swapped with the crank.
Similar threads
