A leak here, burning oil there and so on. 79 GS 750

[cloudkmr]

So, I have a new set of issues.
A month ago, I put in too much oil because I didnt trust the meter on my bike, which was of course foolish. Bike couldn't start, so I did what I should have done before, changed the oil and filter. The bike ran better than ever for a week or so, but it started to burn blueish smoke. Then from somewhere on the bottom of the engine, black liquid has started to leak which must be old oil from before the oil change and smells of gas slightly as well. It also only leaks after running the bike, and sometimes seems to leak less than other times. I have a few ideas of where it could be coming from, I'll post pictures when I get home. Also, when decelerating, there is occasionally a clicking noise that sometimes persists into the idle, then stops once I accelerate again. I have also noticed a drop in MPG's, I had to put 3 gallons in yesterday after only 60 miles on the bike.
I'm thinking of a carb clean up, and I'm thinking maybe the jets need adjusting, but the leak on the bottom of the engine worries me.
Lastly I should add, the bike seems to run great otherwise. Fast warm up, and seems like plenty of power. Any better suggestions would be greatly appreciated.

[mforbes]

Need to make sure your carbs are not leaking into the crankcase. If you smell gas, I would suspect your carbs might be leaking. Gas in the crankcase is not good. Reeks havoc on the bearings, rings, etc. I would suggest you not run the bike until you check for gas leakage.

[TheCafeKid]

Yeah your fuel tap is shot. Replace it immediately. If you've used 3 gallons of gas in 60 miles you're crankcase is likely full of it. This could cause hydrolock and break things for good, but it soundslike the has has watered down the oil so bad it's passing the rings. Had this same issue on a 4 wheeler I'm working on. Dude thought it needed rings and seals. All the rings measured on the new side of spec, just his crank case was FULL of gas, like over the crank full.
Fortunately, it's got needle bearings, so I think he dodged a bullet, but yeah, left like that, it would have been toast quickly.

[Gonzo]

Clean and rebuild them carbs, (new o-rings) and check your float heights and petcock. I just had some trouble with fuel in my oil and it turns out that the float heights weren't set properly. Measured 'em up and now the oil stays nice and black.

Be sure to replace them o-rings too. They're cheap but very important. Worst case scenario here is that you fill a cylinder with fuel and hydrolock. Then you'll have a REAL problem.

[BassCliff]

Hi,

CLICK HERE and go through ALL of the items on both maintenance lists. Stop tinkering with your bike and really get down to maintaining it properly. It's a 30 year old machine and needs a lot of love. If you don't maintain your bike properly it will hound you with issues like this for the entire time you own it.


Thank you for your indulgence,

BassCliff

[cloudkmr]

Thanks to all of you for your replies, its all that I feared and more it seems. I knew I'd have to really get to work on the old girl sooner or later, just unfortunate it came just when we were getting decent weather up here.
I'm doing some shopping now for the carb cleaning, airbox cleaning. My concern really is dealing with my newly mucked up crankcase, how does one go about cleaning that thing out? I havent found much literature about on this site, perhaps it's there, perhaps not. If I've got gunk in there whats the best way to get rid of it?
Also, I'd like to replace the petcock, but not sure which to get, I see at Z1 they have a number of them that are quite varied in price and all. Don't I want vacuum? I'm thinking this guy, http://www.z1enterprises.com/Petcock...zuki-1715.aspx but not sure.
I also read about dips, does something like simple green actually work? Anyone tryed this?

Thanks again

[Gonzo]

I used "Carb Medic: Gunk" for my carb dip. Worked fine. I'd go with a vac operated petcock if I were you. You could do the pingle on/off style, but if you forget to turn it off when you're done riding, you'll be reliving this episode of fuel and oil.

I just changed the oil and filter in my bike. Took some extra oil and flushed it out and I plan to change it again here shortly just to be extra safe. I had to valve covers off at the time and took a syringe with a 1/8 line on it to suck all the oil out that pooled up in there. I suggest you do the same. It'd be a good time to check your valves too if you are going to clean the carbs up. Might as well go that extra step and make sure those are good too.

[JEEPRUSTY]

So, I have a new set of issues.
A month ago, I put in too much oil because I didnt trust the meter on my bike, which was of course foolish. Bike couldn't start, so I did what I should have done before, changed the oil and filter. The bike ran better than ever for a week or so, but it started to burn blueish smoke. Then from somewhere on the bottom of the engine, black liquid has started to leak which must be old oil from before the oil change and smells of gas slightly as well. It also only leaks after running the bike, and sometimes seems to leak less than other times. I have a few ideas of where it could be coming from, I'll post pictures when I get home. Also, when decelerating, there is occasionally a clicking noise that sometimes persists into the idle, then stops once I accelerate again. I have also noticed a drop in MPG's, I had to put 3 gallons in yesterday after only 60 miles on the bike.
I'm thinking of a carb clean up, and I'm thinking maybe the jets need adjusting, but the leak on the bottom of the engine worries me.
Lastly I should add, the bike seems to run great otherwise. Fast warm up, and seems like plenty of power. Any better suggestions would be greatly appreciated.

If you can remove you air filter and look at the "clean" side of the intake.
I bet its coated in a heavy oily substance.

I am amazed it ran at all with dumping that much fuel. Hell I am amazed a fire didn't start. The bike had to reek of gasoline.

[cloudkmr]

If you can remove you air filter and look at the "clean" side of the intake.
I bet its coated in a heavy oily substance.

I am amazed it ran at all with dumping that much fuel. Hell I am amazed a fire didn't start. The bike had to reek of gasoline.

I only had a few short rides, till yesterday at least, then I smelled like gasoline, but i never really noticed on the bike, not sure why... I will do that, thanks

[JEEPRUSTY]

I only had a few short rides, till yesterday at least, then I smelled like gasoline, but i never really noticed on the bike, not sure why... I will do that, thanks

I was just interested in seeing if the old oil that was leaking from the bike was coming from the airbox tube.

[Big T]

You have several things going on here:

1. Leaky petcock - get a new one
2. Gas in oil - change the oil and filter again
3. Leak - Take off the oil pan and clean it up, clean the oil pick up screen -reinstall pan with new gasket
4. Carbs - you can get a gallon size carb dip at any Napa, O'Reillys or any other auto parts store - be sure it has a basket inside
4b. A friend of mine boils his carbs in 50/50 Simple Green and water. Rinse every well, blow dry

If you don't have a service manual, check BassCliff's site

[cloudkmr]

I used "Carb Medic: Gunk" for my carb dip. Worked fine. I'd go with a vac operated petcock if I were you. You could do the pingle on/off style, but if you forget to turn it off when you're done riding, you'll be reliving this episode of fuel and oil.

I just changed the oil and filter in my bike. Took some extra oil and flushed it out and I plan to change it again here shortly just to be extra safe. I had to valve covers off at the time and took a syringe with a 1/8 line on it to suck all the oil out that pooled up in there. I suggest you do the same. It'd be a good time to check your valves too if you are going to clean the carbs up. Might as well go that extra step and make sure those are good too.

Good to know, I'll look for it. My dad has the on/off petcock, I dont really like the idea of it. I'll get the vacuum one and hope its the right one.

Yea I was planning on checking the valves once I was in there. Thanks for the help with getting the oil out, thats my biggest worry so it is greatly appreciated.

I've never actuualy done any of this so I'll be using this site and Basscliffs quite a lot, hope it goes all well.

[TheCafeKid]

I wouldn't pull the pan just yet. Your leak may actually be from a bad filter cover Oring. Thats more common than a pan gasket leak. If the cap is leaking, the first place you'll see it is the bottom of the motor, as wind blast will draw it all back there. Those Orings usually come with new filters but some brands not. Fram filters makes a filter for your bike, found at advance auto parts, and comes with a new ring. Some people don't like the Fram filters but I've never had a problem.

[cloudkmr]

Took the bike apart a bit tonight, and discovered a few things. Carbs were actually quite clean (I was told they had been cleaned last year sometime by previous owner, Ive only owned the bike 4-5 months now). But I'll still be checking all the parts.



Suspiciously clean or no?

Petcock was indeed leaking. Theres a set up with the primary line going directly to the center of the carbs while there is a secondary tube just going to carb #3 I believe, which dosent seem right. Does this seem odd to anyone else? And what is this second tube anyways? (OEM pictures show two tubes coming up from carb 2 & 3 and then two more tubes coming down from somewhere...


So not quite sure that all means.
The leaking black oil gas gunk is coming out of my exhaust pipes, not the oil filter cover or the oil pan, so the oil in the pipes must have been in the crankcase and is being somehow pushed into the pipes from there. Probably the result of overfilling the bike with oil before the oil change.



Same gunk as whats dripping under the bike.

This is only coming from pipe 3 & 4 (going by spark plug #s, and I should add spark plug 3 was the only one that was wet and very black, which tells me thats where all the gunk is.) So there must be more in there. Though taking apart the engine itself worries me a good deal. But I'll try to get at it when I check the valves.
Lastly the air box was in decent shape, except for the rubber seal on one side as you can see below. Does anyone know where you can get these or what I should do about it? I cant find it even on OEM listings.



Basscliffs site has a tutorial for changing boots and such for the Air Cleaner, and he uses weather stripping in it. Does the weather stripping replace these rubbers things or are there both weather stripping and the rubber seal thing?

I'll be updating when more gets done, waiting for boots and O-rings and new petcock for now.

Thanks again good people

[Gonzo]

That line that goes to the T-fitting on your carb rack is the fuel line and the one that goes to the number 3 is your vacuum line. The larger connection on your petcock is fuel, the smaller is vac. Numbers 2 and 4 also have connections, but those are just breathers that vent to the atmosphere.

I'd clean the carbs just for peace of mind while you have them off. Even though they look clean (and could be, but it has been awhile and it was PO right?) all it takes is something to get stuck in a passage and hose everything up. What's more is that if he hadn't stabilized the fuel and let it sit for too long, it'd start to gum up in there and it'd call for a cleaning anyhow. It'll give you a chance to shine up the outsides too and make em pretty.

I just picked up some weather stripping from Lowe's for my air box. Run where it makes contact and it's good as can be.

One final note, I'd keep a fire extinguisher on hand if you have oil and fuel leaking through the exhaust. I'd hate to see a post about how it took to flame and burned your bike down.