Rule #11

[andtheacademics]

I can tell you right now I'm a shoe-in for rule #11

I bought a 1978 GS750 that has a freshly powder coated frame, powder coated wheels, a handful of other cool-sounding customizations and a "rebuilt engine."

Agree on price, send guy money, hire shipper (bike in TX). Then he emails me, "oh, by the way it's been sitting for a month so you might want to clean the carbs."

Here's the bike in the driveway


Now I've had it running with a touch of fuel system cleaner - It does not run so well - it was not idling at first then I played with the idle knob - then it idled, then it died. Some pops. Kept trying to start but killed the battery before it would hold steady.

Left it in the garage for a couple of days.

Lets say I'm not on good terms with the PO, I did some research and found the PPO and asked him some questions

On what work he did to the engine:
"rings valves seals and gaskets."

On the bike not running:
"oh. well it ran when i sent it.the clamp on filters that i put on sucked. they wer cheap chinese clamp ons. the carbs wer spotless. i went thru the entire bike. frame up paint bushings bearings etc. with the pipe and those air filters it needs a jet kit which i did not install."

The clamp-ons in question:

(#4 fell off while I was pushing the bike in the garage and I ran over it, so I gave it a custom tape job I think it has some rat-rod flare)

Now I got the bike running in the driveway today and it sounded fine for about 30 seconds then started pouring out white/grey smoke and leaking black fluid (99.991% sure it's oil) from the clamp that holds the slip-on part of the exhaust.

I've committed to clean the carbs anyway because they are leaking gas from the intakes like crazy (thanks BikeCliff for linking to the CV tutorial!!) and am doing that tomorrow - they're already pulled. *before I get a lecture on tuning I would like to say that I have the stock air box but it has been swiss cheesed and there is no filter or bolts.

What on earth do I do now?

Also if the signals don't flash, only light up steady in the direction you flip the switch for as long as your thumb engages the switch, does this indicate that your flasher relay is burned out?

Also, is this post too long?

Thanks

A

[BassCliff]

Greetings and Salutations!!

Hi Mr. andtheacademics,

It sounds like you are pretty much on top of things. Mr. Nessism's CV carb rebuild guide is the proper procedure. But your bike has VM carbs. See the VM carb guide for assemblies specific to your carbs.

Yes, you will either need to pick up a good airbox and filter or get some good K&N pods and jet accordingly.

Don't neglect any of the other maintenance items in your "mega-welcome". Check the petcock, charging system, valves, etc. Here we go!

Let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[MisterCinders]

Not sure what kind of black fluid would leak from your muffler. But CHECK YOUR OIL FOR GAS SMELLS. If the ****ty pods and carb set up caused fuel to flow into the engine, your oil may be compromised, if you smell any gas in the oil, change it and the filter before starting the bike again.

Ditch those pods. If you decide to stick with pods, get some K&N pods, not the cheapo ones. Then begin the jetting adventure. On that front, several of us have made the same changes to the gs750, so we can point you in the right direction on jetting. If you want to work with stock jetting, you can pick up an airbox from eBay.

Looks like you have stock signals, so try replacing the signal unit. You can pick up a new one at Auto Zone, etc. for about $6. It plugs right in. See if that works. Since you have to hold the switch also, you might need to dig into the wiring and that switch to see why it doesn't stay on.

Otherwise, start through the big list, even with that PPO's assurances.

[DannyMotor]

Ive got a spare airbox if you need it... it needs a makeover... hahaha.

As for the flashers go to AutoZone or AdvanceAuto and pick up the chapest 2 prong 12v flasher they have... $10 normally... thatll fix your flashers.

white smoke sounds like a vacuum/petcock issue... but youre on the right track to rebuild and balance the carbs first.

[bottobot]

I don't have anything valuable to add but I will say I'm sorry you had a poor purchasing experience. It never feels good to get ripped off.

[andtheacademics]

Thanks so much for the replies guys!

I don't have anything valuable to add but I will say I'm sorry you had a poor purchasing experience. It never feels good to get ripped off.

...For a while I was hunting for gallows-building forums@!

I'm wondering if I should try and jury rig my air box for the time being - from what I've read on the forum it seems like using the stock box keeps the bike running much more predictably and, given my current situation, that would be a welcome change. Plus - Coming from a 120hp SV1000 I don't know that a nominal bump in top end HP from pods is really going to light my jets in the way K&N might want me to think it will. (pun intended!)

However - I would need to get air box boots and the only ones I've found are on ebay and the guy is asking $75 *@%$!

Including the shipping and work I've done so far I'm around $2,750 into this project, and if it ever turns on I'm sure california is going to want some registration money!

So if air box + covers + filter + bolts + new boots > Jets + Pods I think my decision may be made for me...

I will check the oil when I get to the garage today - do you think sitting w/ fuel system restore for a few days could have done any level of damage?

If there is oil leaking into the cylinders could a proper valve adjust correct that?

It's likely too soon to tell!

[tkent02]

Flashers...Wait.
It looks like you have the rear signals disconnected?
If that is true, the signals won't flash, they will just come on and stay on.
Hook the rear signals up and they will flash. It needs the current flow of both bulbs to make the flasher work. This is done intentionally so you will know when a bulb is out.

[rustybronco]

and it sounded fine for about 30 seconds then started pouring out white/grey smoke and leaking black fluid (99.991% sure it's oil)[<NOT!] from the clamp that holds the slip-on part of the exhaust.

Carb's need working on. Pull, clean, write down main jet size and clip position on the needles and post up the numbers.

[tkent02]

Thanks so much for the replies guys!



...For a while I was hunting for gallows-building forums@!

I'm wondering if I should try and jury rig my air box for the time being - from what I've read on the forum it seems like using the stock box keeps the bike running much more predictably and, given my current situation, that would be a welcome change. Plus - Coming from a 120hp SV1000 I don't know that a nominal bump in top end HP from pods is really going to light my jets in the way K&N might want me to think it will. (pun intended!)

However - I would need to get air box boots and the only ones I've found are on ebay and the guy is asking $75 *@%$!

Including the shipping and work I've done so far I'm around $2,750 into this project, and if it ever turns on I'm sure california is going to want some registration money!

So if air box + covers + filter + bolts + new boots > Jets + Pods I think my decision may be made for me...

I will check the oil when I get to the garage today - do you think sitting w/ fuel system restore for a few days could have done any level of damage?

If there is oil leaking into the cylinders could a proper valve adjust correct that?

It's likely too soon to tell!

Don't start it again until you check the oil for gasoline. First thing first, if the oil is full of gas, it will smoke, and it will likely drip out the exhaust pipe. The oil is way too thin, and it will get past the rings even if they are good, hence the smoke. After a while they will get worn due to lack of lubrication, hopefully this has not happened yet.
Replace the oil with good oil and see why the fuel got there, bad petcock or was it left on Prime?
Once that is fixed, and with new oil, try to start it again.

He should have adjusted the valves when the engine went back together but you hold certainly not trust him to have done it, check the valves yourself.

The fuel system stuff should not have hurt anything.

I may have an air box, but it will be a while before I can get to it.

Someone here will have a decent airbox for you. Pods work OK, but a pain in the butt as far as I am concerned, cleaning and oiling them constantly, jetting, etc. For a trouble free ride, the stock air box can't be beat. It will be slow as sh;t compared to your SV 1000 either way.

[ChicagoBob]

A GS750 is pretty fast, but you have to rev it. It doesn't have the torque of a V-twin but, if you stick with the carbs & aribox, you'll get a great rush when you hit 6,000 rpm, and a great wail from that pipe.

[andtheacademics]

It will be slow as sh;t compared to your SV 1000 either way.

Yeah I'm pretty sure I'm going to miss the torque! The SV was not very comfortable though, and terrible for passengers. I don't go the track and I ride in the city often, so it was almost too nice for my purposes. Plus, I caught myself "accidentally" going 110mph+ a few times...

tkent02 Flashers...Wait.
It looks like you have the rear signals disconnected?
If that is true, the signals won't flash, they will just come on and stay on.
Hook the rear signals up and they will flash. It needs the current flow of both bulbs to make the flasher work. This is done intentionally so you will know when a bulb is out.

I was actually mounting them at that point - the bike did not have rear signals (PO: "you should have asked." @#$&!) And I was hoping that what you described was the problem. Got new signals (They were 1-wire signals that I had to take apart and re-wire to 2-wire to get a response from the bike) and same problem, just now with four lights instead of two. I'm thinking I have a bad flasher relay AND something funky going on with the switch since it doesn't stay on steady by itself, I have to hold the direction with my finger. Also, when the right signal is lit (bulb @100%) the left signal seems to light up very dimly (maybe 20%) and vice versa.

Carb's need working on. Pull, clean, write down main jet size and clip position on the needles and post up the numbers.

OK! I'm going to get off the internet and do exactly that! It's just so distracting... maybe if I look at enough pictures of other members GS's mine will magically start running on its own?

Carbs/ Main Jets + Clips/ Oil check - I'll post results tonight.

[tkent02]

maybe if I look at enough pictures of other members GS's mine will magically start running on its own?

Let us know how that works out for you.

I'm thinking maybe not so much.

[andtheacademics]

tkent02Quote:
Originally Posted by andtheacademics
maybe if I look at enough pictures of other members GS's mine will magically start running on its own?

Let us know how that works out for you.

I'm thinking maybe not so much. tkent02Quote:

So far - no luck! Maybe I will try yelling at the bike...

Alright I've got the carb bodies out and nekked- PPO was not lying they appear to be clean as a whistle! I was able to pull out the float hinge with my fingernails. I am half way through now - but I started with carb #3 as it was the leakiest/ problem carb. I suspected a gummed float for my leaking-out-the-intake issue, but that's out - could it be the float is not bent correctly OR I've got a petcock issue?

as tkent02 metioned:

Replace the oil with good oil and see why the fuel got there, bad petcock or was it left on Prime?
Once that is fixed, and with new oil, try to start it again.

I sat it for a few minutes on PRI when I was initially trying to start the bike while I ran into the house and googled what the hell "PRI" means. Then ran out and switched her back to "ON" - now, if my floats are working correctly but my petcock is freely dumping gas could that overflow the bowls?

Can you test if your petcock is functioning properly without risking other components?

Gotta run to the harware store to get a nice svelte screwdriver to get the screws out of the top of the slides!

[tkent02]

Can you test if your petcock is functioning properly without risking other components?

This from another thread today...

There are two paths for fuel to get through the petcock into the crankcase.
One is a holed diaphragm, fuel flows down the vacuum line into the #2 carburetor, and into the intake port. The petcock will still function normally as far as shutting off the flow of fuel when the engine is off, and unless the hole is very big, it will still turn on the flow of fuel when the engine is running. To test for this, check for fuel in the vacuum line. You should be able to suck on the vacuum hose and not get any fuel.

The second path is by the rubber o ring not sealing properly, so the fuel cannot be shut off. It just leaks all the time. When it is on the bike, full tank, and with fuel in the line to the carburetor there is a vertical drop of over a foot, this creates quite a syphon. If the petcock can't seal perfectly fuel will flow slowly the whole time until the tank is emptied into the crankcase. If you take the hose off to look you lose the vacuum of the syphon, it is possible that it won't leak while you are watching it. A good test is to run a fuel line from the petcock down a few feet to a container with some fuel in it, go to prime to fill the hose, move it back to ON, mark the fuel level in the container, and go away for a while. If you come back and there is more fuel in the container than there was, you have a slowly leaking petcock. It only takes a few drops a minute to put a gallon or so onto your oil over time, very hard to detect a slow leak just by looking at it.

If you want a decent reliable motorcycle, just skip all the testing and buy a new petcock. The old one did it's job for thirty years, get a new one and forget about it for another thirty.

Edit, for your VM carbs it's the #3 carburetor where the vacuum line to the petcock comes from. This was written for CV carbs.

[MisterCinders]

So far - no luck! Maybe I will try yelling at the bike...

Alright I've got the carb bodies out and nekked- PPO was not lying they appear to be clean as a whistle! I was able to pull out the float hinge with my fingernails. I am half way through now - but I started with carb #3 as it was the leakiest/ problem carb. I suspected a gummed float for my leaking-out-the-intake issue, but that's out - could it be the float is not bent correctly OR I've got a petcock issue?

as tkent02 metioned:


I sat it for a few minutes on PRI when I was initially trying to start the bike while I ran into the house and googled what the hell "PRI" means. Then ran out and switched her back to "ON" - now, if my floats are working correctly but my petcock is freely dumping gas could that overflow the bowls?

Can you test if your petcock is functioning properly without risking other components?

Gotta run to the harware store to get a nice svelte screwdriver to get the screws out of the top of the slides!

PRI = Prime, meaning the petcock supplies fuel through gravity without any vacuum.

If your petcock fails, it can allow fuel to leak through the vacuum tube into the No. 3 carb, bypassing the needle valve and flooding that carb, etc.

A simple test for the petcock is to remove the tank, connect a fuel line and vacuum line to the petcock. Turn to PRI and see if gas flows from the fuel line. If so, that's good. Is there gas in the vacuum line? Not good.

Then switch to ON. There should be no fuel flow at all. If there is, not good.

Now apply a little suction to the vacuum line. If you are worried about drinking gas (don't do that) you can use a Mighty Vac or decent size syringe. It doesn't take a lot of suction to activate. If fuel comes out the fuel line, good. If it also flows into the vacuum line, not good.

I just went through the gas flooding ordeal, but my petcock was not the problem. Check the needle/seat assemblies and the washer to make sure they are working properly. I also found some interference from the bowl gaskets was blocking the floats.

If it all looks right, reassemble the rack and hook up a fuel line. Load the bowls and see if they leak, flood, etc. If one carb in particular is overflowing, remove the bowl and run some gas through the line. Raise the exposed float by hand and see if gas continues to drip from that carb. That finally revealed that my needle seat was not sealing well and allow gas into the bowl despite the float valve.

HTH

Edit: just saw tkent's post. That slow leak test is another good idea, and I will take a go at that myself to confirm my own petcock seals.