Reving issue not as fast as before

[jorge1320e]

Hey guys hope doing fine!!

I been a owner of a FZ6 2004 since dicember and when I first got it the bike would rev up to red line. Since a couple of weeks I been having the issue that it wont rev up fast anymore, after it reaches 12k rpms it goes up slow to 14k. Any clues what I can check ?

I have already done the following:

+ Cleaned the tps sensor
+ Cleaned the K&N air filter
+ Changed spark plugs

about a month ago I cleaned the fuel pump filter, the gas tank did had lots of rust shells, Im thinking the pump is the issue but not sure what do you guys think ?

 

[TownsendsFJR1300]

There was re-call on the TPS here in the states for your year bike, might want to check into that.

BTW, how did you clean the TPS? Have you checked the #'s, (throttle wide open and throttle closed) for the TPS?


All that crap / rust in the tank may have very well got past the fuel pump filter. As your getting to 12,000 RPM's, I'd say your pump is working.

The injectors have VERY SMALL orifices. It doesn't take much to clog them. WOT is when they NEED to be fully operational. I'd be looking towards those, (remove and have cleaned / tested).

You really need to get all that rust out of the tank (if you haven't already).

 

[jorge1320e]

I follow a youtube video on how to clean the tps. I used contact cleaner i believe its called. I will clean the injectors and clean the tank once again.

 

[TownsendsFJR1300]

Check on the TPS re-call (its a FREE FIX) AND AT LEAST test (costs nothing) the TPS #'s thru the dash..

 

[jorge1320e]

Hey well I cleaned out the fuel pump and the gas tank. The fuel pump was really dirty with rust shells. After everything was cleaned out I installed it back again put new gas and the bike went back to normal. It gets to red line without any trouble.

 

[jorge1320e]

 

[TownsendsFJR1300]

Glad the filter caught everything.

There are different methods for removing rust from the inside of the tank. Looks like you got most of it cept for the top.

Electrolysis works very well as well as chemical agents. I would try to get the rest out just so your not doing "a do over" later down the road.

The inside of my old tank before I sold it (minor scratch on the outside):

 

[jorge1320e]

Well guys im back again, I cleaned out the tank last week and removed all the rust it had.

Im facing some kind of trouble with the bike. When I first start it with engine cold it revs low around 900 rpms and if I even touch the throttle it stalls. When it warms up the iddle goes to normal. Also when I want to have full throttle the bike buggs out a little and then it goes up and revs. Any idea what else should I check ?

 

[TownsendsFJR1300]

Well guys im back again, I cleaned out the tank last week and removed all the rust it had.

Im facing some kind of trouble with the bike. When I first start it with engine cold it revs low around 900 rpms and if I even touch the throttle it stalls. When it warms up the iddle goes to normal. Also when I want to have full throttle the bike buggs out a little and then it goes up and revs. Any idea what else should I check ?

Not sure about the idle, might be (related) but I think you need to pull the injectors and have them cleaned. Sounds like some crap made it down to them.

I would do that first...


For the cold start idle, coolant hose, #30: https://www.partzilla.com/catalog/yamaha/motorcycle/2004/fz6-fz600ss/intake-2 carries coolant to the large part(Not numbered in the diagram-where you do you sync adjustment).

When the engine is cold, that unit raises the cold start idle. That may be clogged in there not allowing cold coolant to circulate.. Once it warms up, it drops the idle down to normal...

 

[jorge1320e]

Hey guys well I solved my issue, It turned out to be the gas pump. It wasnt giving enought pressure. When I conected the manometer to it, it was only giving 26 psi when it should have 36psi. I changed it and problem solved bike is like new now, has its power back to normal and the iddle issue was fix also.

 

[FinalImpact]

Hey guys well I solved my issue, It turned out to be the gas pump. It wasnt giving enought pressure. When I conected the manometer to it, it was only giving 26 psi when it should have 36psi. I changed it and problem solved bike is like new now, has its power back to normal and the iddle issue was fix also.

Glad you were brave enough to go back in. That little pressure regulator is the key. Its a controlled leak and once full of debris it doesn't maintain pressure as it can't seal with chunks in it. Usually they can be cleaned by pushing them off their seat.

If you think about how little time the injectors are open at idle and cold start the pressure loss matters.

If it were mine I would pull the injectors, apply 12v to them and backflush them with solvent. They likely have debris in the inlet impairing flow.

In addition to what was mentioned above you can also fill the tank with solvent and pea gravel. Shake until rust is gone. Clean and dry as needed. Its the quick and dirty method of knocking rust free.