1978 GS1000 wont start, sat 10 years

[matt8874]

I have been googling for days but just cant seem to find the perfect answer. This bike was given to me a week ago from my grandpa and it sat for 10 years, he did a lot of work to it about 7 years ago and only drove it up the road, I think he said he reshimmed it and something else. So heres a list of what I did to it when I got it home.
-Cleaned the carb out, wasnt much dirt or anything, I think he did that already but I cleaned the whole thing anyway
-Changed the oil and filter, not sure how much oil it takes but I put in 3qts of Mobil1 10w40
-Installed new battery
-Installed new air filter
-Cleaned gas tank as much as possible, tank had a bit of rust inside. I used a bottle of rust remover and sprayed the hose inside to break up the chunks
-Cleaned off the fuel float inside tank
-Put some seafoam in with about a half gallon of gas

I tried to start it, with the choke half way it didnt want to try to run. With the choke all the way down it acts like it wants to run, instead of just cranking over it has a little hesitation like its about to start but then doesnt. I will post pics soon, any help would be much appreciated!

[seanarthurmachado]

Can you define cleaning the carbs ? If they sat for 10 years they will probably need a good 24 hour soak in Berry man's, and might be a good idea to start checking rubber bits.
(Mine was just cleaned and 3 of the 4 intake boots had cracked o rings)

Also when staring on choke/enrichener DONT touch the throttle.

[allojohn]

It's always a good idea to make sure it's a runner before investing the tons of time and money necessary to make this machine safe and reliable. You could be dealing with fuel starvation. You say there's rust in the tank, did you clean out the petcock? Although you've cleaned the carbs they be choked with rust particles again. Do yourself a favor and start reading about your 37 yr old bike. There are no short cuts to reliable/safe riding, none. If you do not do the job properly you will have nothing but trouble and will park the bike back where it's been for the last 7 year.

Service manual 78 GS1000 Read this!!!

Carb cleaning

[JEEPRUSTY]

Maybe all the wter in the gas is stopping it from starting?

[tom203]

Grampa's bike! Time to get serious then and realize your brief carb cleaning doesn't cut it. Go here , this explains how to do it right

http://members.dslextreme.com/users/bikecliff/images/vm_carb_rebuild.pdf

if your tank has chunks of rust, figure it sent some done into carbs and this will continue . Once you attack inside of tank with chemicals, the tank tends to rerust until you seal it.
There's other maintenance on your to do list....

http://members.dslextreme.com/users/bikecliff/images/GSR_Greeting.html

[matt8874]

There was no more water inside the tank, if there was it was a few drops, but I put seafoam in with the gas so that should stabilize any small amount of water present.
I cleaned the carb by removing it and disassembling it and used carb cleaner spray on the components. I did not clean the petcock, I dont know what that is anyway, I am not very familiar with carb engines. Here is an update with pics.

[seanarthurmachado]

The petcock is thefuel valve pointing down near your choke lever

Carb cleaning with spray won't help. Needs to be stripped and dipped to get all the tiny passages.

On a glance the "where does this go to" is the vacuum tube on the petcock. That allows gas to flow when not on prime and works an an "auto off" for the petcock.

[allojohn]

Looks like Gramps had some trouble there. The fuel filter was added because he probably had rust going to the carbs. The fuel tap/stop cock is the petcock. Open it up and clean it. The petcock operates on a vacuum and the vacuum tube has been removed, it should be connected to the nipple on the side of #3 carb.

[matt8874]

So the petcock is the fuel control on the second to last image? And you are saying that the nipple on that which doesnt have a hose needs to have a hose connecting to the #3 carb on the third image? And I need to clean the petcock still

[chuck hahn]

100% derust the tank. Remove petcock and sending unit. Tape holes with GORILLA tape..not cheap duct tape.. 5 gallons of 8% vinegar soak for a few days 2 or 3 at least.

Rebuild carbs per the supplied tutorial and get 1 VM oring kit here. see page 3 of the siute for intake oring information as well.

http://cycleorings.com/

If it were mine I would also do a tank liner and be done with rust issues period. I believe the tank will again rust at some point and I just get it lined and done with..but thats my opinion. Caswell 2 part epoxy kit or POR 15 are both excellent products.

Get rid of the inline filter..they actually are designed more for systems with a fuel pump than gravity feed systems like ours. They tend to actually slow down and block fuel flow as many here have found out the hard way.

Once your done with a real and proper carb job and the tank is good the bike will run. At this point you do a vacuum sync with gauges.

[chuck hahn]

PS.. I suggest the vinegar because its cheap and it will not harm the paint if it gets on it.

And another thought..after 10 years sitting that petcocks oring and diapram are likely to be junked. If it leaks dont buy the expensive GS 1000 petcock. get a petcock for the 77 /78 GS 750...same petcock for about 1/3 the price of a 1000 one.

Do you understand how these petcocks function and what each setting does??? Its operated off the vacuum nipple going from carb 3 to the petcock nipple. Carb 3 is the third one from the left as your sitting on the bike.

With the petcock in the ON position and when the engine runs it sucks open a diaphram that lets fuel flow..and automatically shuts it off when not running.

The petcock in the PRIme position fuel will constantly flow with or without the engine running. This function is for exactly what its called..to prime the empty barb bowls if they are empty for whatever reason...such as rebuilding them. You should never leave the petcock in PRI if you need to use it..PRIme the carbs, start the bike, and immediately out it back in the ON position.

[matt8874]

I will try the vinegar and use the Caswell epoxy kit. I will also take off the petcock and make sure its free of rust. Should I install a new fuel line and take out the fuel filter after I clean the rusty tank? And I know it has been quite some time since its been ran but as far as I know all the gaskets and stuff were replaced, but that was like 7 years ago so should I still replace them? This seems like a money pit

[JEEPRUSTY]

You know as long as you have spark why not use a shot of starter fluid to see if it runs?

[allojohn]

This seems like a money pit

Doesn't have to be but some things like o-rings will need replacing, they're are among the cheaper things. The tires are definitely shot - how much are you prepared to put into it?

[Guest]

All toys are money pits