Throttle Problem

[Silent21]

Hello fellow Riderz,

I have a problem with my Baby.  While riding it began to sputter as if it was running low on fuel, luckily a gas station was near by.  So I was able to get the station and add more fuel, shortly after leaving the gas station the bike stopped on me.  Now it will idle but when I turn the throttle it immediately dies.  I check the fuel line to see it was kinked ir pinched and it is fine and the vent line from the tank seems to be venting properly and is not pinched.  (These were possible problems I found on the Net).  Does anyone have any ideas what could be going on?

PS she's a 1990 fj with 11k miles.

[rktmanfj]

Hello fellow Riderz,

I have a problem with my Baby.  While riding it began to sputter as if it was running low on fuel, luckily a gas station was near by.  So I was able to get the station and add more fuel, shortly after leaving the gas station the bike stopped on me.  Now it will idle but when I turn the throttle it immediately dies.  I check the fuel line to see it was kinked ir pinched and it is fine and the vent line from the tank seems to be venting properly and is not pinched.  (These were possible problems I found on the Net).  Does anyone have any ideas what could be going on?

PS she's a 1990 fj with 11k miles.

Make sure the fuel pump is working.  You should be able to hear it clicking when you turn the key until it builds enough pressure.

Check the fuel filter under the tank.

[racerman_27410]

could be the fake reserve... try switching the reserve switch to on.


other than that i would suspect some trash has gotten into the jets and the carbs need cleaning.



KOokaloo!


Frank

[Silent21]

Hello fellow Riderz,

I have a problem with my Baby.  While riding it began to sputter as if it was running low on fuel, luckily a gas station was near by.  So I was able to get the station and add more fuel, shortly after leaving the gas station the bike stopped on me.  Now it will idle but when I turn the throttle it immediately dies.  I check the fuel line to see it was kinked ir pinched and it is fine and the vent line from the tank seems to be venting properly and is not pinched.  (These were possible problems I found on the Net).  Does anyone have any ideas what could be going on?

PS she's a 1990 fj with 11k miles.

Make sure the fuel pump is working.  You should be able to hear it clicking when you turn the key until it builds enough pressure.

Check the fuel filter under the tank.

Thanks for the quick reply.  The fuel pump is working properly as far as I can tell. 

[Silent21]

could be the fake reserve... try switching the reserve switch to on.


other than that i would suspect some trash has gotten into the jets and the carbs need cleaning.



KOokaloo!


Frank

I will check the reserve switch.  Thanks.

[fj12_rider]

I would SERIOUSLY consider not letting the bike run into the reserve , Once the light goes on on my bike I fill her up . The lower you let it run in the tank the more chance you have of getting bits of shit coming through and blocking up your filter . everything below the main pipe for me is considered to be "emergency fuel' and I dont think I`ve use it on any bike in the last 3 years for that reason .

Check your tank is supplying the filter , then check the filter is supplying the pump , then the pump to carbs and lastly strip and clean the carbs . I had the same problem on a zzr and it was the fuel filter was knackered and was letting crap through and it blocked the carbs .

[Super_v500]

Try a dummie tank gravity fed straight into the carbs, if it runs fine on this then there's something up with pump, filter or pipes.

[SlowOldGuy]

I would SERIOUSLY consider not letting the bike run into the reserve , Once the light goes on on my bike I fill her up . The lower you let it run in the tank the more chance you have of getting bits of shit coming through and blocking up your filter . everything below the main pipe for me is considered to be "emergency fuel' and I dont think I`ve use it on any bike in the last 3 years for that reason .

Old wives tale, simply not true.

This would indicate that the shit in the fuel is always floating on top which is not true.  If it's flosting or on the bottom of the tank, it's going to be stirred up and find it's way into the fuel line regardless of how much fuel is in the tank.  Doesn't hurt to run the tank low and doesn't have any influence on crap getting to the carbs.  If you want clean carbs, make sure the tank is also clean.  In 28 years, I've never had crap in my tank.

Also, these bikes don't have a "reserve pipe" on the petcock.  Just one inlet on the petcock.  The early models give you an incredibly inaccurate gauge and light.  The later models have a stupid reserve switch that turns the fuel back on after the black box turns it off.  Fuel pump models also have a "simulated" reserve function.  None of the models have a petcock with a reserve position to pull fuel from a lower level in the tank.

DavidR.

[fj12_rider]

In 28 years, I've never had crap in my tank.

Thats not possible , if you get your gas from a regular pump no matter what you do there will be a certain amount of crap in the gas , even if it hasn`t given you any issues . the only way you would stop that is to filter it on the way in . Even then with the transfer of the nozzle from vehicle to vehicle who knows what you are collecting over the years . One piece of grit here another there and over 20 years thats a lot of grit. Thats why you have a fuel filter. If that wasnt the case you wouldn't need one . Gas will always have impurities (crap) in it that will settle on the bottom of the tank over the years , my bike is 22 years old and when I replaced my fuel filter it certainly wasnt clean . I`m not really familiar with the fuel system on the fj I just became a new owner , but on previous bikes I had more issues letting the tank run low simply because the ratio of gas to crap is reduced and therefore more crap is sent through the filter because of the movement of the fuel in the tank when riding . Nothing to do with the length of the pipe etc . We`re not talking about "lumps " of crap here we`re taking about miniscule particles that will block jets and the like . I`m almost certain the OP`s bike has blocked jet/filter because there is junk in there .

[andyb]

Calm down kids.

Yes, your fuel is often carrying a bit of particulate load. 

More goes into it from the tank's rusting, frequently.

The engine is just fine with a limited amount of crap being burned through it.  Honest, it is.  Fuel filters are wear items and need replaced sometimes, the carb float needle seat screen thingies the same, etc.

I would cheerfully run my bike down to the last drop on gas that was pumped while the station was being refilled (stirring up their tanks) rather than let it sit for two weeks without running at all, letting things varnish up.  Plugged jets are bad, and they can plug with a variety of sources and for a number of reasons.


While David stops and breathes, I suggest that mister new owner considers not arguing with one of the people on the forum who is considered to be one of the carb tuning/cleaning/maintaining gurus.

[fj12_rider]

I wan`t arguing , just expressing my opinion  . If it isnt allowed . Apologies !

[SlowOldGuy]

Yes, crap is everywhere.  Most of the stuff in the fuel is so small it goes right through the system without clogging anything.

As Andy said, the most common source of debris in fuel is rust from the tank.  That's not the fault of the fuel, it's the result of a lazy owner. And most fuel filters will not stop rust from getting to the carbs, even brand new filters.

A vast majority of clogged jets I've seen were plugged by dried fuel residue, not particulates.  Particulates are a problem, but they usually come from the air filter side and clog the bleed holes on the emulsion tubes. This is usually the result of using K&N filters (or no filter, same thing).

Everyone is entitled to their express their opinion.  It's the FACTS that I will dispute.  If you have crap in your fuel tank, it doesn't matter whether it's full or almost empty.  The sloshing fuel will stir it up and it will get into the carbs eventually.  Even the act of filling the tank will stir up the residue.  Not running the tank low doesn't prevent anything, that's an old myth (just like losing the clutch ball bearing when starting the engine without the slave cylinder installed).

If you suspect that there's debris in the fuel system, then it needs to be cleaned.  I've spent a lot of time over the years making sure I maintain the fuel systems on all my bikes by adding stabilizer, running them frequently during periods of inactivity, and draining and re-filling periodically if I can't run them. 

This is even more important given the crap fuel we now have to cope with.

DavidR.