Pod filters / Diff. Pipes / Rebuilt carbs.... what to do?

[mozez]

Hey all,

Its been a while since posting, but Ive got quite a bit done. Again, please excuse poor lingo or terms, but Im learning.

Heres the story...
Bought a '78 GS750 from someone who said it hadnt run in 2 years.
Rebuilt the carbs (from a '77 GS750), changed the oil and filter, changed spark plugs and checked connections.

Now - let me state that I have not synched the carbs, but have checked the depth of air and fuel screws properly. I dont have the proper tools to synch the carbs. is it a bad idea to try do anything more before synching?

Heres the Great news! - She fired up, made noise and road around the block in a very rough state.

Heres the Bad news... Only idles with the choke open fully, and on Prime. Dies otherwise.
Belches out grey / white smoke from the left exhaust. Also, the pipes on the left hand side are blowing out grey smoke at the connection where the pipes go into the engine. Any ideas?

The bike came with pod filters, and the ugly cruiser muffler things, and the connection of the pipes to the engine seem very sketchy....

Im sure this is all adding to my problem, but Im not sure what sequence to trouble shoot things in.

Please see attached pic.

Any help or advice would be greatly appreciated.

Cheers.
Mozez.

Anyone in Vancouver B.C ? I have quite a few parts kicking around, if you would like to trade.

[petelardo]

Don't know if this will really help you much, but my first suggestion would be to get the mechanical stuff straight BEFORE you try to deal with the carbs. At least PART of the problem you've described can be caused by the exhaust pipes not being properly mounted to the engine block. People have been known to break / strip exhaust bolts, so approach this CAUTIOUSLY. Find out WHY the exhaust isn't sealing properly, and correct it. Exhaust pipes use gaskets to create a proper seal; check this diagram to see how everything goes together:

http://www.bikebandit.com/partsbandit/showschematic.asp?dept_id=995410

The exhaust gasket is listed on the microfiche as GASKET, EXHAUST PIPE, and shown on the diagram as part number 4. The Suzuki Part Number is 14181-01D00. Logically, with four exhaust pipes, you'd need four gaskets if you wanted to replace all of them at once. You can get them through your local stealership, or buy them through mail order, if that is more convenient for you.

I do hope you have some type of repair manual (Clymer, Haynes, or whatever); there is a real benefit to being able to study photos and read through a procedure several times BEFORE you begin the work, so a service or repar manual is always helpful. That will also help you to decide if you need MORE information to accomplish something; you'll have a better idea of which questions to ask, which can only help the work go more smoothly.

Don't simply buy new exhaust gaskets thinking that they will solve the problem; take the time to examine the exhaust system, comparing what is shown on the diagram with what you see on your motorcycle. Logically, you'll want to do this with a COLD engine, unless you think burn scars are attractive... Buy a LARGE can of penetrating oil, in case you encounter rusted / frozen bolts (an all-too common problem), and apply it to the exhaust bolts every time you even THINK about working on the motorcycle, to give it time to work. When you are finally ready to pick up your wrenches, you'll have a fighting chance of removing at least SOME of the bolts without breaking or stripping them...

RUSHING this type of work will only lead you to disaster; one common mistake I've seen is when people install NEW exhaust gaskets on top of OLD ones... When they tighten the exhaust bolts, the extra gasket material in the exhaust port puts too much pressure on the (steel) bolts, which strips the aluminum threads out of the cylinder head, and NEW problems are created...

Well, I hope I've helped point you in the right direction with this post... If you lived within a thousand miles of me, I'd try to schedule a visit to help you, but things don't always work out the way we'd prefer...

You can find online parts diagrams through these links (among others):

http://www.bikebandit.com

http://www.mrcycles.com

Keep in mind that BikeBandit part numbers are NOT Suzuki part numbers, though MRcycles DOES provide the actual Suzuki part numbers...

Simply find the links on those pages to the OEM parts for Suzuki, and the rest should be obvious... if it ISN'T obvious, you'll quickly figure it out...

At the risk of repeating myself, do NOT attempt ANY repairs or adjustments to the carburetion system UNTIL you have the entire exhaust system working properly; exhaust leaks can cause you to burn exhaust valves, which means $$$$ surgery, which you'd be better off avoiding...

Best of luck with this; there are others who post here more qualified than I am to help you with this, but hopefully, this post will help to get the ball rolling your way...

[80GS750]

you are probably going to have to jet the carbs if it hasnt been done before... those pods open a lot more air flow than you need with stock jets...

i put pods on mine, and am installing a v&h 4-1....

i bought the dynojet stage 3 kit and its awesome.. works great.

make sure those carbs are squeeky clean, cause any little bit of crap in there will cause problems, mine would not run (doing same thing yours is doing) and i had to take mine apart 3 or 4 times until i found the problem.. i had 3 pilot jets clogged..

keep on workin on it man!!!

mine went from this


to this in about 1 month.....

[mozez]

Cheers!

Thanks for the advice. Makes sense to fix obvious problems before trying to figure out whats 'not' wrong.
will keep ya posted.

[petelardo]

I edited my original post; I typed it while trying to fight off a migraine, and lost the battle...

Good luck with this; let us know if you need more information...

[mozez]

Belated update...

Just a quick update to the last post.

Petelardo, thanks for the exhaust suggestions ...."exhaust pipes not being properly mounted to the engine block" ..
This was indeed the case, and with a little bit of tightening and some spacers to account for the long (weird) mounting bolts, the pipes are sitting really snug.

The bike is still struggling to start and Idle, and is still running super rich (Black spark plugs) - when I manage to get it going.

So I think my next steps are....
Re-jet and remove the two floatbowl vent lines at carbs 1 and 4.
Get new points and condensors. (Im hoping this will help the idle, and the tough starts)

As always - any other suggestions are always welcome.
Thanks again for this amazing resource!

will keep posting with my (slow) progress.