Another Stalling Thread

Joined
Jan 15, 2012
Messages
60
Reaction score
1
Points
8
Location
California
Visit site
So for the past months my bike (07) has been stalling randomly when I pull the clutch in, mostly within the first 20mins after start up but has done it after a long ride. To get the bike to start back up I usually have to crack the TB's, its smells pretty rich after. My idle is set to 1200-1250rpm and I've cleaned the air filter and replaced the spark plugs within the last 200 miles. I checked the TPS and its within spec (16-101) and doesn't skip and numbers.

The bike is an 07 with 40k mi with a Scorpion exhaust and K&N filter.

Any ideas? I'm trying to make time soon to check the valves and I'm ordering a carbtune to sync the TB's
 

TownsendsFJR1300

2007 FZ6
Site Supporter
Joined
Feb 7, 2009
Messages
12,516
Reaction score
1,157
Points
113
Location
Cape Coral, Florida, USA
Visit site
Do you have an after market fuel controller?

Were the spark plugs blackish / sooty when you removed them?

If there is a fuel controller, disconnect all of it and check results.

Has anyone messed with the CO adjustment (thru the dash-hot wiring it?)



BTW, it's VERY RARE the engine will run that rich (stock-Scorps won't bother it).


Being a California model (I assume), I know there's differences for emissions. What they are, I dunno, someone else will have to chime in..
 
Last edited:
Joined
Jan 15, 2012
Messages
60
Reaction score
1
Points
8
Location
California
Visit site
I was running a PC3 but sold it about 2yrs ago. The plugs looked a little sooty and no I've never messed with the CO adjustments. Yes the bike was originally sold in CA and I have installed AIS Block Off Plates and have removed the catalytic converter. All the mods were done 2-3yrs ago.

I did notice the other day, while trying to adjust my idle a little higher to see if that would help, it won't go and higher. I can lower my idle but 1200-1250 is max no matter how for I turn the screw
 

TownsendsFJR1300

2007 FZ6
Site Supporter
Joined
Feb 7, 2009
Messages
12,516
Reaction score
1,157
Points
113
Location
Cape Coral, Florida, USA
Visit site
Tks for the update.

I don't think the TB sync will stop / cause the richness but can get you more adjustment. - If need be, open #1 adjustment screw 1/8-1/4 turn and sync to that. You should get more adjustment (able to raise the idle more).

Just for S&G's, try disconnecting your battery for 15-20 minutes, re-set the ECU...

Lastly, I believe, [MENTION=15974]FinalImpact[/MENTION] posted previously about the wax pellet near the fuel rail for COLD START UPS. If yours has junk / sticking, etc, the engine COULD be fueling itself as if it was in "cold mode" ALL THE TIME, (VERY RICH). Do a search for that thread(s). It's very, very possible that is your issue. Should that be stuck / clogged in the cold mode, it'd be rich ALL the time.

Just above the fuel rail (not numbered for some reason) in the pic, where you would do your sync adjustments is where the "cold start" works with coolant flowing thru the unit: https://www.partzilla.com/catalog/yamaha/motorcycle/2007/fz6-fzs6wc/intake-2




[MENTION=2579]Motogiro[/MENTION] -Cliff, do you know if any of the sensors, coolant temp, etc could tell the ECU the engine is COLD when it is not, keeping it in "choke/cold" mode??
 
Last edited:

Motogiro

Vrrroooooom!
Staff member
Moderator
Elite Member
Site Supporter
Joined
May 8, 2008
Messages
14,968
Reaction score
1,138
Points
113
Location
San Diego, Ca.
Visit site
[MENTION=2579]Motogiro[/MENTION] -Cliff, do you know if any of the sensors, coolant temp, etc could tell the ECU the engine is COLD when it is not, keeping it in "choke/cold" mode??

Yes, the coolant temp sensor, air temp and air pressure are 3 sensors that might affect running mixture.
 

Motogiro

Vrrroooooom!
Staff member
Moderator
Elite Member
Site Supporter
Joined
May 8, 2008
Messages
14,968
Reaction score
1,138
Points
113
Location
San Diego, Ca.
Visit site
Nice to see a fellow San Diegan!

Are there anyways to test these sensors? Both the coolant temp and air temp are reading gauge.
There are procedures for testing sensors. Do you have a service manual? If not, let me know. I'm near Miramar, SD:) If you need, I'll help you.

Sent from Moto's Motorola
 

Motogiro

Vrrroooooom!
Staff member
Moderator
Elite Member
Site Supporter
Joined
May 8, 2008
Messages
14,968
Reaction score
1,138
Points
113
Location
San Diego, Ca.
Visit site
TownsendsFJR1300 is going to email me the service manual. If I get stumped ill pm you, I'm in La Mesa near Grossmont Center
I'll also pm you my telephone number. I go to Guitar Center in La Mesa. Spent a few bucks there!

Sent from Moto's Motorola
 

FinalImpact

2 Da Street, Knobs R Gone
Site Supporter
Joined
Mar 16, 2011
Messages
11,137
Reaction score
184
Points
63
Location
USA, OR
Visit site
FWIW the ECM is just a look up table, when the temps are low (air and coolant) it fuels according to the map which is set to richen the mixture based upon those inputs coupled with the rpm.

All of that said does your engine change rpm with temperature? If not the coolant may not be circulating through the control circuit or contamination has bound it so it doesn't move.

That aside it still sounds like the sync screws need adjusted to give you some freedom to set the RPM appropriately.

It's been a while since I've tinkered but you might just turn them all out 3/4 of a turn (or in) to raise the idle and gain control of the idle speed circuit.

Make sense?
So, what does the coolant look like in this machine? Has it been maintained or did it ever pour out looking brown and full of chunks?
 

FinalImpact

2 Da Street, Knobs R Gone
Site Supporter
Joined
Mar 16, 2011
Messages
11,137
Reaction score
184
Points
63
Location
USA, OR
Visit site
FWIW my fuel controller says the idle AFR is 12.75:1 or 4.7% CO. So if you look in the manual and read the S1 turning data it seemed like it listed something like this for CO%.

When you get the RPM and the vacuum to spec this gets pretty close (co%). Of course steady state off idle has most of the fuel map around stoir (14.7:1) where the CATs burn efficiently.

So, before you mess with it to much, throw a vacuum gauge on it and get #. Just use a T right at the vacuum sensor works pretty good.

Quick rule of thumb.
Vacuum to high - can be to lean
Vacuum to low - can be too rich

To lean can be vacuum leaks or excessive ignition advance.
To rich can faulty ignition system, restricted air filter.
 
Joined
Jan 15, 2012
Messages
60
Reaction score
1
Points
8
Location
California
Visit site
FWIW the ECM is just a look up table, when the temps are low (air and coolant) it fuels according to the map which is set to richen the mixture based upon those inputs coupled with the rpm.

All of that said does your engine change rpm with temperature? If not the coolant may not be circulating through the control circuit or contamination has bound it so it doesn't move.

That aside it still sounds like the sync screws need adjusted to give you some freedom to set the RPM appropriately.

It's been a while since I've tinkered but you might just turn them all out 3/4 of a turn (or in) to raise the idle and gain control of the idle speed circuit.

Make sense?
So, what does the coolant look like in this machine? Has it been maintained or did it ever pour out looking brown and full of chunks?

Interesting... Ive changed out the coolant twice in the 7yrs I've owned it and its never came out looking that super nasty or chunky. it might be worth doing another flush and cleaning out the control circuit
 

FinalImpact

2 Da Street, Knobs R Gone
Site Supporter
Joined
Mar 16, 2011
Messages
11,137
Reaction score
184
Points
63
Location
USA, OR
Visit site
Interesting... Ive changed out the coolant twice in the 7yrs I've owned it and its never came out looking that super nasty or chunky. it might be worth doing another flush and cleaning out the control circuit


Does your engine speed start off higher when cold and drop any amount when warm?

If no, then something is wrong with idle air control valve.


I've never taken the IACV off but this gives you an idea...
attachment.php


attachment.php



attachment.php
 

FinalImpact

2 Da Street, Knobs R Gone
Site Supporter
Joined
Mar 16, 2011
Messages
11,137
Reaction score
184
Points
63
Location
USA, OR
Visit site
Ahhh..... I wasn't sure. NP!

Did you see if OP said the rpm changes as it warms?

I'd guess one could take the two bolts out and inspect the section with the coolant hoses going into it, but never heard of it being an issue.

There is the black cap on the other end. One screw holds it on. Inside is nut on the shaft that moves. Maybe gently push or pull on it to see if it moves?
No brute strength.

attachment.php
 

FinalImpact

2 Da Street, Knobs R Gone
Site Supporter
Joined
Mar 16, 2011
Messages
11,137
Reaction score
184
Points
63
Location
USA, OR
Visit site
If idle air control valve is stuck or dead, it almost explains the rich no rpm change but stalling is **almost always** a lean condition.

The only thing that sorta makes sense is the IACV has been stuck for a long time and someone F'd with the sync screws making it what it is.

Just saying they can handle a lot more rich than they can a little lean. Lets see what happens!

Wonder if it has a thermostat?
 
Top