Carbs out of balance 3 times in 2 weeks?

[bruce_launceston]

Any ideas what could be throwing my carb balance out. I have balanced them at idle 3 times and 'on the throttle' twice in the last 2 weeks?
I have checked cable seats all sitting okay, I wondered if I had a 1/2 throttle cable fraying but not that I can see.
Bike ran fine on the weekend 300km ride but was out of balance again on monday morning. I have balanced them on idle tonight and the manometer wasn't far out but it was idling rough and even hesitating on take-off which is unusual. The manometer oil level was moving with some throttle on but I didn''t adjust the cables again until I try to find out what is going on.

It is 18 months since I rebuilt the carbs etc and it has been running beautifully since then, untill 2 weeks ago.

Any ideas??

[Rob Valdez 79 R65]

How long has it been since you took your cable splitter apart?

[Barry]

I sometimes get those symptoms from a little water in the float bowl or around the needle jet and  emulsion tube.

[bruce_launceston]

Hi Rob, I had the splitter apart 18 months ago when I fitted a new throttle cable - splitter to carb.

Barry, I did think I might have picked up some bad fuel from a country town. I found some water in one float bowl a week ago and have run a cup of metholated spirits through with a tank of fuel and have since had a couple of tanks of fresh fuel. I will check the bowls again tomorrow because it does feel like it could be a problem with the fuel in one carby. It was hesitant off idle this morning and bogged down which it has never done before.

[Bob_Roller]

If water in the fuel is a problem, try installing a fuel filter .

I started using one about 6 years ago, always had a 'blob' or two of water in the float bowl when I removed them, along with a fine gritty sediment .

Since installing the filters, no water or debris in the bowls .

How do the rubber tubes between the carbs and cylinder head look ?

Have the worm gear clamps become stripped, and not keeping things secure ?

[Mike V]

Bruce,
Just for grins, next time you have the bike running take some brakleen and spray at the throttle shaft ends and rubber tube connections. Does the idle speed change or stumble?
Are your cables free and not binding?

[bruce_launceston]

Checked level of fuel in bowls this morning and they seem even so floats still seem okay, also no more water in the float bowls this morning.

I fitted a full carb rebuild kit 18 months ago including throttle shaft 'o' rings, I also fitted new rubbers between carbs and cylinder head and the clamps are tight.

I am thinking timing chain??.  It's been about 40,000 km since I last replaced it, or maybe the tensioner needs attention.

Even though I balanced the carbs again last night today it is running rough at low revs and almost stalling at take off.

Or could it be electrical??? but no other symptoms. I have fitted new advance weight springs and lubed bean can about 12 months ago, battery is good, bike always starts okay.

The bike sounds sort of 'tinny' from the left cylinder when I ride it through town.

[Barry]

My similar problem was caused by "oily water" from the engine breather around the needle jet emulsion tube. I put that down to not getting the oil warm enough in the recent very cold weather.  It seems unlikely with your climate and mileage but may be worth a look.
Between carb overhauls I think it's a good idea to Drop the main jet holder out occasionally even with the carbs on the bike just to make sure there is no crap accumulating in there.

[drewboid]

How low are you trying to tune the idle? I have heard that the R65s (or CV carbs in general) are smoothest at about 1000 - 1200 RPM and trying to tune them lower can be a problem. (others can chime in now and tell how their bikes will idle at 700 RPM, only my /2 will idle that low)

[bubby-joe]

How low are you trying to tune the idle? I have heard that the R65s (or CV carbs in general) are smoothest at about 1000 - 1200 RPM and trying to tune them lower can be a problem. (others can chime in now and tell how their bikes will idle at 700 RPM, only my /2 will idle that low)

Not to blow any /2 out but there meant to run at 650-750 my R-65  sits at 1000 if I go any lower it starts to bog on acceleration and stalls when I return to an idle at a light.  Mind you this may change as the weather changes, it's FEB/MAR and I'm 90 miles from Alaska as the crow flies, daytime temp averages 40F. It's a little damp but I'm on the road.  The jets and tubes are critical, I had 1 cylinder cut right out with only a small amount of water in one carb, water came from condensation, previously fouled plug is another possibility.

[bruce_launceston]

I think Barry might be on the right track. I have had a few drops of oil dripping from the hose clamp nearest the right carb that must be from the engine breather.

I will find some time and check this out further.

[Rob Valdez 79 R65]

I've never been happier since I ran my breather to atmosphere - some time around 1983...

[bruce_launceston]

Hi Rob, have you or can you post some details on how you did that, where you ran it to, did you use a filter or catch container etc?

Cheers Bruce

[Rob Valdez 79 R65]

Hi Rob, have you or can you post some details on how you did that, where you ran it to, did you use a filter or catch container etc?

Cheers Bruce

I ran it to the back of the bike, with a filter at the end.

here is a previous post detailing it.

http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1263739044/3#3

[bruce_launceston]

Hi Guys, I pulled the main jet holders out tonight. The right side holder had a black oily sludge around it and the left side had a white water/oil sludge on it.

I will see if it runs any better tomorrow.

Sometime soon I will have to drain and dry out the tank and while it's off I will have a look at relocating the oil breather pipes out of the air intakes. (Not tonight though, it's a long weekend and I want to take my bike to the Tas Rally.)