Gas Overflow on Prime, Tachometer Not working ETC...Suggestions?

[smoothbomber23]

Just cleaned and dipped the carbs on my 86 GS450L as well as changed the regulator to one of Duane's (thanks again). I have a couple problems with the bike I need to get in order:

1. The gas seems to overflow from a hose that goes to the air box while petcock is in prime position?

2. My tachometer just stopped working all together two days ago, the light has been out for about a week, and now I have no movement at all with the tach needle?

3. Green Nuetral Light won't come on, but it used to when I would rev the bike to higher RPM's, now I get nothing?

4. Most importantly the bike is acting like I am running out of fuel at idle, basically it will just sputter to a stop. It has been running fine for about a week without doing this. (I did have this problem before but just reprimed the carbs put the petcock to reserve and then filled up with gas and was good to go)?

Any suggestions/comments would be greatly appreciated!
Thanks in Advance

[GMSKEE]

Hey smoothbomber23, I had the same problems, well almost

Break Down:

1) Fuel Overflow - Turn Prime off, only use that when taking your bike out of storage, or it could be a faulty petcock. Mine did the same you just have to find the correct position.

2) Tachometer does not work - Disconnect the line, and inspect the cable, its pretty easy job to take off. More than likely the cable inside snapped, you will have to replace. In canada the cabel should be about $25.00.

3) The Nuetral light wont come on. - Your probably getting low resistence or not enough for that matter. Check that the wires are not corroded or worn out. Sounds like you have a faulty connection.

4) Idleing issue - First only run the bike on reserve when your out of gas. Having said that sounds like a fuel issue. It could be dirty carbs, spark plugs could be fouled. Dirty air filter. Try running the bike with the petcock on ON, not on Prime or Reserve

Hope that helps

[Dave8338]

Have you checked that the voltage output at idle is correct? Should be at or near 12V, up to 14.4V at 4000RPM +-

[BassCliff]

Hi,

Let me quote one of my favorite people here in GSR-land...

Overflowing Carbs by Mr. bwringer

Let me point out the obvious: If a carb (or carbs) are overflowing when the bike is not running, you have TWO problems. First, your petcock should prevent ANY flow; second, the needle valve should allow flow only up to a fixed height in the bowl (ie, not overflow). Excess fuel has to make its way past both of these parts.

(A third possibility on old carbs is for fuel to flow past the inlet seat O-ring. [n/a for VM]. That doesn't apply to newly rebuilt carbs, since the owner has just installed brand new. Right??)

I'm not 100% sure why some needle valves leak and others don't, but I'm starting to lean with Keith Kraus' suggestion, which is to use only OEM valves and seats. Simply because it works. The question why is a separate matter. (I have a theory, but no guinea pig to test it on at present).

For the petcock, you'll hear a number of suggestions. I think that the vacuum operated petcock should be kept operational, for a few safety reasons.

Several of the folks here are convinced that petcock rebuild kits are useless, and your only real option is to buy a new OEM petcock.

For now, for people who are 100% sick of carb overflow & the ensuing problems, the consensus then is to go with OEM petcock, seats & needles. it's expensive, but it seems to be the only certain way to correct this BS once and for all.

(I would add: no doubt there are people whose overflow problems began when they installed carb rebuild kit(s). The machining on the parts is often abhorrent and inexcusably amateurish, and the f&^%#ing O-rings don't fit correctly. The consensus for a while now has been to buy gaskets IF you need them, valve seats & needles IF you need them, and an O-ring kit.)


The petcock does not, in any way, REGULATE the rate of flow. It should be either on or off. If you have overflow on a running bike (and it's not inhaling fuel through the petcock diaphragm via the petcock vacuum line) then there's a problem with the inlet valve.

Either:

1) the float is no longer buoyant enough or is badly adjusted, or

2)the valve is bad, or is being held open by some foreign matter.

You may need to lubricate your tach cable (or replace it) and lubricate inside the tach itself. Take off your gauges, turn them upside down and put a few drops of your favorite lube in there (3-n-1 oil works pretty well in the tach and speedo).

It also sound like you need a multimeter so you can test your charging system using The Stator Papers. Make sure you have a good, fully-charged battery. The electrical system will benefit greatly if you check and clean every connection and ground on the entire wiring harness. Keep us informed.


Thank you for your indulgence,

BassCliff

[Redman]

Just cleaned and dipped the carbs on my 86 GS450L as well as changed the regulator to one of Duane's (thanks again). I have a couple problems with the bike I need to get in order:

1. The gas seems to overflow from a hose that goes to the air box while petcock is in prime position?

2. My tachometer just stopped working all together two days ago, the light has been out for about a week, and now I have no movement at all with the tach needle?

3. Green Nuetral Light won't come on, but it used to when I would rev the bike to higher RPM's, now I get nothing?

4. Most importantly the bike is acting like I am running out of fuel at idle, basically it will just sputter to a stop. It has been running fine for about a week without doing this. (I did have this problem before but just reprimed the carbs put the petcock to reserve and then filled up with gas and was good to go)?

Any suggestions/comments would be greatly appreciated!
Thanks in Advance

1. Dont leave it on PRIme. IF it leaks real bad in a short time (minutes, hours, not days, weeks) when on PRIme, then that doesn not mean there is a problem with the petcock, it means there is problem with the float needle valves in one or more of the carburators.
If the float needles leak a little bit and then leave petcock in PRIme, then it may flood over into air box after many days or weeks, and that is not so much a problem, just dont leave on PRIme.
If leave on PRIm and it foods over to air box in a matter of hours, then that that is such a bad leak that can not control float bowl level and could cause running problems petcock in regular position.

2. Tach not working is not related to the instrument light being out. The tach is mechanical. Check the cable to see it the cable in the cable is broke.

2 and 3.
If you are starting to have lots of lights burn out; Get a volt meter, Check your battery voltage at mid rpms. If real high, like over 14.5 volts, then is a problem with the regulator or regulator not grounded.

3. Green netural light, used to light when rev engine. Hum, maybe its just the engine vibration makes the broken filiment in lightbulb touch back together. Replace the bulb in the instrument cluster. (Buy 2 or 3 while you are getting one.)

4. I am not the mechaninc here, but, Hum, wonder if engine is running out of gas at idle, if so then carbs need cleaning.
Or... hey, whats the chance the engine isnt running out of gas but flooding at idle for same reason as problem #1.