Electrical system is awake...next step drain carbs or full clean?

[Guest]

Hi Folks,

I feel like I'm starting to get somewhere with my first ever project bike (it was a "ran when parked but bring a trailer" situation).

There is power to all the lights, the gear shift indicator, the starter, etc. (I have gained a new respect for contact cleaner). Now I want to focus on getting the engine running before rebuilding the brakes, changing cables, etc. I'm not sure what to do next.

The guy I bought the bike from said he had rebuilt the carbs before it sat. However, the fuel tank was in rough shape, and the gas was dark brown and smelled bad (I still need to restore the tank, but how well I restore it will depend on whether I can get the bike running). Anyway, today I drained one of the carbs and got some pretty foul-smelling gasoline but nothing like what came out of the fuel tank.

Should I drain the other 3 carbs, still on the bike, and see if I can get it the engine to run using a "temporary" fuel tank? Or do I need to go ahead and pull the carbs for a full cleaning right away...or at least clean the float bowls?

Thanks!

 

[jsandidge]

Well, you can't do any harm by hooking up a temp tank to see if she runs. But first, open up the oil fill and give it a sniff. If the petcock has gone bad, (and many of them do) you could have had gas leaking past your cylinders into the crankcase. If the oil smells of gas, it could be diluted and thin.

BTW, welcome to the forum from another Drew!

 

[cowboyup3371]

You’ll save yourself more time in the long run if you pull the carbs and properly disassemble, clean, and replace orings per Nessism’s guide now.

 

[tom203]

Yes, bite the bullet now and get those carbs off for cleaning?.avoid frustration in starting attempts with gummed up carbs?..or starter fluid

 

[Redman]

From your description of thick goop in bowls, there probably is thicker stuff in carb small passages that will need to be cleaned out. ANd a proper cleaning, dissasembly, soak in carb dip 24 hours each. Not just spray carb cleaner here and there.

But if you want to prove it to yourself, yah, drain the carb bowls, and try to get it to run. Will be good expereince. Maybe it might run on full choke only and maybe not all cyclinders heating up. Or maybe it might only sputter and backfire.

Hey... have wee seen pics of this 650?
Typically we require to see pics before givening any advice.

 

[Nessism]

Carb rebuild tutorial and Newbie Mistakes thread are linked in my signature. Please go through these to see what you are up against.

Personally, I won't even attempt to start the bike until the valves are adjusted and the carbs properly refreshed.

Realize that we are talking a GS, so it's extremely unlikely that you will have any engine mechanical issues (unless the valves were neglected.)

Regarding the tank, you first need to remove the varnish, and then attack any rust that may present itself under the varnish. It's a one-two process. You can't do both at the same time.

Good luck

 

[sacruickshank]

Count me as another vote in the "pull the carbs and give them a proper cleaning" category. Based on other info, it is extremely likely the idle circuit passages and tiny jet holes are clogged. I've tried to start some without carb cleaning, but it's super rare you'll get that lucky.

Anecdotally, I tried the non-cleaning approach one time with a GoldWing that also had a blown starter clutch. The kids were not too happy when I asked them to help me push it back up the hill after yet another failed bump start.

Re: Nessism comment about valves, I don't always do the valves before that first test start. It's always satisfying to hear it come to life, even if it's not perfect.

 

[Guest]

Thanks everyone...this forum is great! This seems like a perfect time to learn how to clean carbs and check valve clearances, and all of the resources from generous folks are really going to help.

As far as photos of my bike, Rich82GS750TZ helped me post one when I did my intro message (the "top case" had to be retired), but I had too much fun riding my other bikes to work on the GS until winter finally hit. Here is a more recent pic.




p.s. I'm glad I found a cheaper source for kerosene...I'm planning to spend a lot of time in the garage this winter

 

[sacruickshank]

Thanks everyone...this forum is great! This seems like a perfect time to learn how to clean carbs and check valve clearances, and all of the resources from generous folks are really going to help.

As far as photos of my bike, Rich82GS750TZ helped me post one when I did my intro message (the "top case" had to be retired), but I had too much fun riding my other bikes to work on the GS until winter finally hit. Here is a more recent pic.

p.s. I'm glad I found a cheaper source for kerosene...I'm planning to spend a lot of time in the garage this winter

For me, the nastiest part of checking valve clearances is getting the petrified gasket material off the valve cover and cyl head. That is my least favorite part of rescuing these old bikes, which is why I test for basic engine firing before doing the valve check.

 

[Nessism]

How can "basic engine firing" be performed when the engine may have valves hanging open from neglected maintenance? The 2V GS engines have incredibly tight valve clearances so there isn't a whole lot of tolerance for abuse in that regard.

 

[rphillips]

Very good advice around here, a good complete cleaning & replacement of gaskets "O" rings & stuff will assure you everything is correct, even if all they really needed was a shot of starting fluid. Valves have got to be checked, I can't think of any possible benefit to waiting till later...Good luck & keep us updated.

 

[timebombprod]

me personally id do a carb rebuild, kbs coatings has a really good rebuild kit but if i were you i would just clean the tank out and not seal it, whatever stuff they use to clean it is amazing because my tank was spotless.

these carbs are really easy to rebuild as they all use the same exact parts so you cant mismatch with any serious repercussion, what i will say though is you will want to note the carb body and the corresponding floats so you dont have to reset the float or fuel height if they were correct beforehand.

 

[timebombprod]

me personally id do a carb rebuild, kbs coatings has a really good rebuild kit but if i were you i would just clean the tank out and not seal it, whatever stuff they use to clean it is amazing because my tank was spotless.

these carbs are really easy to rebuild as they all use the same exact parts so you cant mismatch with any serious repercussion, what i will say though is you will want to note the carb body and the corresponding floats so you dont have to reset the float or fuel height if they were correct beforehand.

.....just found out people have already replied to this.

for the valve adjustments you can literally use a ziptie to get enough clearance to pull the shim out.

 

[sacruickshank]

How can "basic engine firing" be performed when the engine may have valves hanging open from neglected maintenance? The 2V GS engines have incredibly tight valve clearances so there isn't a whole lot of tolerance for abuse in that regard.

I guess every bike and mechanic is different. Some are more patient & methodical than others, seems like I fall into the less patient end of the spectrum.

For my current $250 GS650L project, I did the test fire yesterday after cleaning the carbs and replacing the air filter, but not checking the valves, It started, idled, and revved up and down correctly. This confirmed that the engine isn't DOA, without the time and hassle of dealing with a petrified valve cover gasket. It only has 12k miles, so even if the valves were never checked they should be at least close, unlike a high mileage bike that potentially never had a valve check. Now I'll pull the valve cover and start the gasket removal ordeal.

Agreed there is a risk of a valve being frozen open, are the 8v GS's interference engines? You can pull the plugs, manually crank the engine, and look through the spark pugs holes to check for issues.

I've resurrected early 80's Goldwings and CX/GLs, which do have an interference engine design (at least the Goldwings do). I always check the valves on those, but the task is simpler since Honda uses an easily replaceable rubber valve cover gasket rather than Suzuki's fiber gasket.

 

[Guest]

Now that CycleORings.com has ceased operations, has anyone found a good alternative? It looks like the next step would be to order o-rings in each of the sizes shown on the guide?

 

[sacruickshank]

Now that CycleORings.com has ceased operations, has anyone found a good alternative? It looks like the next step would be to order o-rings in each of the sizes shown on the guide?

I used the ebay source that has been mentioned in other threads about oring availability. Delivery and quality seem fine, but it is difficult to differentiate between some of the rings that have similar but slightly different sizes. Image below shows the combined orings for the fuel tee, fuel transfer tubes, vent tee, and bowl drain. I ended up not trying to differentiate them and everything seems fine so far.

 

[Guest]

I used the ebay source that has been mentioned in other threads about oring availability.

Ah...I missed all of that discussion - thanks! Parts are on order.

p.s. The seller had a photo of Prince on his Hondamatic.

 

[Guest]

Well...it turns out there would have been no reason to try and start the bike. Things are much worse that I was expecting. Carbs are very dirty and I'm running into some problems.

It's looking like the guy who worked on the carbs didn't know about JIS screwdrivers. Almost all of the bracket screws had stripped heads, so I used the trick from the guide and the forum.


After lots of time and tapping, they finally all came out (I plan to replace them all with hex bolts).

When I opened the first carb, things looked pretty rough. The slide hardly moves, and everything is coated in varnish. The thing that concerns me the most is seeing this stripped head. I'm not sure what this is called, but it holds the clip that prevents that jet from coming out. Any recommendations? I don't think I can fit vice grips in that small opening. Can I throw the whole thing into the ultrasonic to try and loosen things up, or will that hurt the diaphragm? I can't get the slide and diaphragm out the way things are now.

 

[cowboyup3371]

Cut a slot in that screw with a dremel to fit a flat blade screwdriver then spray a few rounds of PB Blaster in there just to be safe before removing it.

 

[Nessism]

A set of Vessel Impacto screwdrivers are great for removing stuck carb screws.

https://www.vesseltools.com/handtools/screwdrivers/megadora/980-series-detail