[ctrobins]

Hi,
I just rebuild my carbs (using the Randakk kit) Yay! Even though it looks like two octopuses were in a fight on it with all the vacuum tubes etc. I'm pretty sure all the tentacles ended up in the right places.

I just balanced the carbs also.

I adjusted the Idle mix screws at '3 turns out' from seated.

Here is my situation that I'm hoping to get some advice on:
I set the choke, and the bike starts right up.
BUT, it won't idle if I set the choke completely off. Even when the engine is warm.
so to avoid the engine dying at stops, I reach for the choke as I'm slowing down and open the choke just a little to keep it running.

Should I just adjust the choke to be a 'little open' all the time? Or is there some other thing I could do to fix?

Thanks!
- Craig

 

[ctrobins]

Thanks Pinto and Truck! (I think that was the name of a cop show in the 70's )

I think I'll work on the Idle screws first, and adjust the choke cable properly. I really want to be sure it's needed before I deal with that double-octopus again! (double-octopus = carbs)

- Craig

 

[ctrobins]

To clean the carbs.. I'd call it an overhaul.

I removed the whole 4-carb assembly from the bike.
Disassembled the hoses and all 4 carbs (keeping each set of parts together)
Disassembled each carb, jets, needle valve, Idle screw and meticulously cleaned each piece with Carb cleaner. Sprayed carb cleaner through ALL the ports then blew compressed air through everything. I checked each jet and verified that all the little holes and ports were clear.
I then re-assembled, adjusted the floats to 7mm.
Adjusted the Idle screw to "Seated, then backed out by 3-full turns"
I used all new vacuum and fuel lines.

The carbs did have a lot of gunk in them, and the pins on the needle valves of a couple of the carbs were stuck.. I unstuck them. I would be really surprised if there is some skunge that I missed, after all that.

I used the Randakk rebuild kit with all new gasgets and o-rings.

I'm hopeful it's just the Idle screws that need adjusting!!! The idle problem I described seems only minor, The choke just needs to barely be on for it to run OK.

- Craig

 

[ctrobins]

I did replace ALL the fuel lines.. from the petcock to the carbs, and new fuel filter.

I did NOT soak the carbs. Just gushed carb cleaner through everything.

Another 'clue' that may help with diagnosis, Is that the bike DID seem to Idle ok at 900-1000 RPM's prior to be rebuilding the carbs... so, I'm hopeful that my cleaning didn't actually introduce 'muck' into the system.

Idle speed screw vs Idle Mix/Pilot screw, I understand the difference. The Idle speed screw is set to idle a little fast (about 1,300 rpm)... I did the carb balancing with it idling this way... I think I had the choke completely off during the balancing, I'll probably need to re-check the balancing.

The Idle Mix (Pilot) screws were all exposed already, and I took them out, inspected cleaned and re-installed replacing the o-rings and washers (from the kit). I did read in the manual about the 'Pilot Screw Adjustment'.

(I appreciate all your input!)

- Craig

 

[ctrobins]

Thanks Dizzy! Thats the kind of tip I can live with (jet streaming with the carb cleaner.). Because, I REALLY hope I don't have to take that carb assembly apart again.

I'll try these various suggestions out, and post back the results.

 

[ctrobins]

I tried the 'back flushing' that Dizzy suggested. I did it on just 2 cylinders... the right side (which is where I suspect the issue was coming from.) I THINK IT WORKED!

The bike WILL Idle now without the choke... but, the idling is very rough. I will try to balance the carbs again and see where it leaves me.

 

[ctrobins]

Ugh... I don't know if the fuel tank is clean! I did put a new fuel filter... But, I know the bike had been sitting for some time (maybe over a year) prior to me getting it 2 weeks ago, so I bet there could be some filth in the tank as well. I'll check that out!

Thanks for the suggestions!

 

[ctrobins]

UPDATE:
I looked down the filler neck of the gas tank. It looks like there are spots of rust, or some other form of contamination lining the inside walls. There may still be some 'old' gas in there too. When I bought the bike it had about 2 gallons of fuel in it (I don't know if it was new or old gas), and I filled up before I drove it home.. so maybe it's 50/50 bad gas.

 

[ctrobins]

Thanks for your input guys!

The bike does seem to idle OK now, and I feel pretty comfortable going on some shorter rides (where I can call my wife or kids to pick me up in an emergency

I did open up the tank and got a good look inside. I think I found the lost city of Atlantis in there! The fuel itself looks clear enough, but, there is a bit of flakes and crud down inside and rust on much of the inner surface. I think I'm going to have a project to remove and derust / clean the tank.

I suspect that any 'chunks' that may break loose and make their way into the fuel line will be caught in the new fuel filter, but I'd feel a lot better if I knew the entire fuel system was clean.. and free of whatever petroleum based life-forms are in there!

 

[ctrobins]

Conclusion

Just to wrap this thread up...

I discovered that the fuel tank had a lot of rust crumbs in it. To fix this, I cleaned the fuel tank... I did not want to go through the process of removing the tank, so I cleaned it while still mounted. The final result is that the bike idles and runs VERY smoothly now, and seems to have a lot more power and excellent throttle response.

Here's how I cleaned the tank.
1) Remove the fuel send unit. Closed the petcock and removed the fuel line
2) siphon the old fuel and discard (it was old and full of rust gravel)
3) Sprayed a bunch of carb cleaner into the filler tube and the open fuel send area.
4) using a stiff (and skinny) toilet brush I scrubbed the insides of the tank as best as I could reach.
5) poured a little fresh gas in (to rinse)
6) Siphoned that out, trying to suck up as much debris as possible.
7) poured in 2 gallons of Evaporust. (waited overnight)
(I was hoping this would dissolve the rust crumbs... but it didn't. But, I did to a pretty good job of derusting the parts of the tank the liquid touched. I made sure to siphon a little of the Evaporust into the petcock valve to try to clear the tube out a little also
8) Siphoned out the Evaporust (using a tube about 1/2 inch diameter.)
(I discovered, using a larger diameter tube is good for sucking out the crumbs)
9) Poured about 2-3 gallons of water into the tank, scrubbed, siphoned..and siphoned some water through the petcock. REPEAT a few times. After about 4 cycles of this there were very few crumbs left... but, still not 'like new' inside
10) I used a small sponge on the end of a stick to try to blot dry and pick-up any finer debris still in the tank.
11) I let the tank air dry for a while. It was still a little damp inside when I decided to pour in a little Sea Foam and 1 gallon of gas to get the bike started.
It started right up and was running great!

I went on a short ride just to make sure the carbs had all new fuel in them.. then got to the gas station to fill up the tank with brand new gas!

I appreciate all the tips and advice folks provided and I hope this info is helpful for others... even if it's an example of 'How NOT to clean a gas tank'.

And that concludes my little adventure... for now!
- Craig