RUNNING LEAN

[JOMPPA10]

Hope you understand my guestion. Anyway ifixed carbs with new needleset and o-rings( my previous post) but ididnt drive bigger distances , only work to home 5-10 km.
Last week i took longer journey abouth 1000 km and bike worked fine about 30 km and stop. this happenened numerous time in my trip ( 50-100 times). wery frustrating .
Carbs cleaned , but ibelive that my engine get air in somewhere? and its get owerheated because one smoke session off the road and then she goes again like anything. And
my bike is 3cv pump version no petcock etc. And how i know that bike is running lean, sparkplugs are very very vhite.
happened.

thanks again

[mr blackstock]

Hello,

I would think check the screws on the rubber tubes connecting carbs to engine head, look for a kink in the fuel pipe from tank to carbs, check petrol tank cap breather is working, perhaps after all that then remove carbs, re-check floats are in correct, re-check fuel flow into carbs.

cheers, Gareth

[the fan]

If you have no kinks in the line, Try opening the gas cap when it dies. It's possible that the tank is not able to breath and starving the bike for fuel.

[JOMPPA10]

If you have no kinks in the line, Try opening the gas cap when it dies. It's possible that the tank is not able to breath and starving the bike for fuel.

I have tried to run bike with gas gap open: same problems (those orange flaps are gone and i bore bigger holes to cap). I put new intake manifolds (4) same problems, now iam trying to adjust needles one clip up.
Hope that helps.

[movenon]

If you have no kinks in the line, Try opening the gas cap when it dies. It's possible that the tank is not able to breath and starving the bike for fuel.

I have tried to run bike with gas gap open: same problems (those orange flaps are gone and i bore bigger holes to cap). I put new intake manifolds (4) same problems, now iam trying to adjust needles one clip up.
Hope that helps.

To make your bike run richer LOWER the clip.  But it should run good in the mid range. I have a few very slight mods and run with the clip in the 4th notch down.

Sounds to me like if you have no fuel flow blockage then the problem in in the carbs..  Refer to the files section and study in detail the carb rebuild files.  If you are running it to lean it can and will damage the top end.  Check every little detail such as the fuel air screw, washer and o ring etc..  If all 4 plugs are white then what ever it is it is in all 4 carbs.  That's why I would recommend to study the files section and go through the carbs as if you had no knowledge of the carbs. Take nothing for granted and take your time. 
George

[JOMPPA10]

NO fuel starvation in fuel line, to this time: new needles+seats+o-rings,new intake rubbers, new facet fuel pump,new carb diags.
carbs sync, only if you pros can say vhy no 1 cylinder in sync needle was mowing rapidly rest carbs were steady vacuum


PAT can you help

[Steve_in_Florida]

...why no 1 cylinder in sync needle was moving rapidly, rest carbs were steady vacuum

Sounds like it's time for a valve adjustment and leakdown test. This will give some indication as to the health of your valves. A burnt valve won't seal, and will give funny vacuum readings.

Steve

[ribbert]

carbs sync, only if you pros can say vhy no 1 cylinder in sync needle was mowing rapidly rest carbs were steady vacuum

PAT can you help

Vacuum gauges can tell you many things about the condition of your motor, as you can see from the face of the one below.



The fact that the needle is moving is not in itself indicative of one particular condition and depends on a range of things.

However, if the needle is just fluttering at idle and only on one cylinder and in the absence of any other indicators, I would punt on a vacuum leak, but just saying the needle moves is a bit vague for an accurate diagnosis.
Steve's right, it could also be valves but I think in this case you would be better off determining the problem by some other means.

Anyway, Pat will sort it out for you.

Noel

[Pat Conlon]

Well....the guys that responded know much more than I...but I'll try..

1) Check you gauge. I am assuming you have a 4 gauge setup. There should be a small line restrictor in the vacuum line that dampens the vacuum pulse. Without this restrictor, the gauge (or fluid column) will dance so bad that you can't get a reading. Swap hoses and see if the dancing gauge moves to a different cylinder...if it does, it's the gauge, if the dance stays on #1 then it's not.

2) There's a reason tuneups should always start with a check on the valve clearances (stone cold engine) along with a basic compression test (warm engine). Steve's advice is spot on.  A tight valve or valves can give you wonky vacuum readings.

3) I agree with Noel, it sounds like you have the vacuum leak issue covered.

[JOMPPA10]

Well....the guys that responded know much more than I...but I'll try..

1) Check you gauge. I am assuming you have a 4 gauge setup. There should be a small line restrictor in the vacuum line that dampens the vacuum pulse. Without this restrictor, the gauge (or fluid column) will dance so bad that you can't get a reading. Swap hoses and see if the dancing gauge moves to a different cylinder...if it does, it's the gauge, if the dance stays on #1 then it's not.

2) There's a reason tuneups should always start with a check on the valve clearances (stone cold engine) along with a basic compression test (warm engine). Steve's advice is spot on.  A tight valve or valves can give you wonky vacuum readings.

3) I agree with Noel, it sounds like you have the vacuum leak issue covered.

May be that no.1 cyl bolt open i cracked piece of head and i haved to do make longer theareads existing hole and use longer bolt . i did use less torgue with that.

[JOMPPA10]

bike is running great but 3000-4000 rpm strong vibration is present, next strong vibration and some power loss in 160 km/h.

[Tiger]

Remove the seat and gas tank...run the FJ and spray some carb cleaner, Brake & parts cleaner, easy start, (or something similar), around the carb manifolds, (but one at a time), vacuum lines, etc...a change in idle speed will indicate were you have, if at all, a vacuum leak.

John.

[JOMPPA10]

Problem solved carbs diags were way too much stiff (was trying to repair with plasti paint) and leaking, new diags and running
fine, now shes running bit rich, but iam pleased , hope this story ends, now i can ride ride hole contininent without stopping

seppo schroderus
finnland