FSE 450 2005 idle misfire/stall when hot

[Tafka]

Okay...i'm out of ideas.
I have a 2005 FSE450, last year rebuild, new crankshaft,piston,cylinder etc.
At one point, this year, in the middle of the forest, bike started to idle rough(misfire) and then stalls. Starts most of the time easy again and runs a little bit but then again, idle/low revs misfire and stalls if not given throttle.
High revs, everything OK. Some backfire when slowing down. Works fine when cold! but about 20-30min riding, engine getting hot, then the issues start.
Can't ride properly because stalls too often when riding slow forest trails.
Changed and adjusted TPS, new fuel pump, water temp. sensor, checked air temp sensor, fuel injector tested-good spray pattern, no leaks and flow rate ok.
Can't find any air leaks.
My next step would be change:
1) Ignition coil - i think i can find VW analogue (hell no i'm paying $200 GasGas "original" coil if i can get VW coil with $25)
2) Fuel pressure regulator? - PITA to find in Estonia :/
3) Pick-up coil? - does anyone know what should be the gap between pick-up coil and toothed wheel?

Any ideas?

 

[Tafka]

Okay progress so far.
Managed to replace original ignition coil with 2013 Honda CBR coil.
Got a brand new fuel pump assembly with fuel regulator for testing.
Put 2007 MAP to ECU, made things little bit better.
But still after all of this, when engine gets hot, at low revs and sometimes when taking off it feels like engine starves and then pulls nicely. Higer revs, everything fine.
I start to suspect maybe leaking valve(seat)?
Out of ideas....

 

[Tafka]

One more remark....when bike starts to misbehave and i pull over for couple of minutes, let the bike idle, and then start to ride again, it works okay for sometime and then starts to act up again.....so something over heats but what???

 

[mikethebike1127]

Have you checked the fuel tank breather??? Might be partially blocked causing a vacuum in the tank!!

 

[Tafka]

No issues with the breather

 

[Nosedive]

Hello,

I know these Issues actually from my 03 FSE.
Please check the valve clearance.
Ex is fine, even about 40k Kilometers after repair.
Can't measure both In-valves, cold 0, think they won't close when hot.

 

[Tafka]

Valve clearance is in spec. Just week ago had valves and valve seats grinded/cut and seated. Tought the valves might be leaking when hot but no change.

 

[Nosedive]

That's fine!
Helps getting closer to the causing part.
The hardware (Motor) is as new,
Software trimmed,
Sensors etc checked,
seems no EFI/fuel/intake problem.
Ignition. Coil is new, so are HV-cable and Plug?
Maybe a brandnew weak spark plug?
Let's think: what else heats up while running: pump relais,
rectifier/regulator,...next step...

 

[Nosedive]

only in german:

from GG mounting instruction

 

[Tafka]

That's fine!
Helps getting closer to the causing part.
The hardware (Motor) is as new,
Software trimmed,
Sensors etc checked,
seems no EFI/fuel/intake problem.
Ignition. Coil is new, so are HV-cable and Plug?
Maybe a brandnew weak spark plug?
Let's think: what else heats up while running: pump relais,
rectifier/regulator,...next step...

Tried different spark plugs, still the same.
If relays would heat up, then the problem would be in whole rev range but my problem is only in the beginning....from idle to 3500-4000 rpm....after that its ok. But slipping clutch and holding revs so high in tricky stuff is pain in the a**.
I will try, at some point, to borrow a second injector....i checked my injector but in the test bench the injector doesn't get so hot...so maybe it's still the injector. Pretty much out of ideas....would like to get it running and then sell the bike

 

[Nosedive]

almost causing headaches...

Two more Oks.
You've already done a lot of good work, man.
Plenty new Parts, lots more checked,
Another injector-test helps.
Don't know much about injectors... thought, good spray or bad spray. Would be nice to let me know the results.
Still got suspicion on ignition.
Can there be a timing-problem when getting hot?
Thinking about the pick-up, heat issue, resistance to engine rpm.
Theory, too early timing (sparking) when hot causes rough run, but less affects at higher revs. Might it feel so?
Improbable, but there's an Info from GG about the flywheel, bent pin causes offset:
only german. Hope it helps.

 

[Tafka]

I don't think it would be pickup coil....resistance seemd ok cold and hot....usually pickup coil works or not, at least i have fixed some engines with bad pickup coil, on those engines the pickup coil stopped working at all or when they got hot then also stopped but when cooled down started working again....haven't seen pickup coil that works ok on high revs and bad at low revs.
But i will double check.
The original injector got tested in the bench when cold and had very good spray pattern and flow rate was in spec.
It feels like the engine fuel mixture gets too lean when hot...when adjusting the CO trim with guzzidiag, it gets little bit better but the problem is still there.
Are you sure that the pickup coil data on your picture is correct? I have a different pickup coil than on your second picture....
I think they changed that in 2003-2004?
If i'm not wrong then the newer pickup coil resistance should be around 500 ohms. Maybe you can find data for newer pickup coil? It's okay if it's in german...have learned german a little bit in school

EDIT: One more thing, that could eliminate the pickup coil....when standing still and let it idle....it usually idles good. When trying to give throttle then theres 40:60 chance that it will rev okay or will sputter/die. So basically the sputter is really bad when there is load...so i would think theres something wrong with the fuel mixture (or timing). But why did that problem start just randomly in the middle of one ride.... :/

 

[Karlos]

Hi mate, all the work you have done sounds reasonable. Just foraleft Reid view point, I am having a similar issue with mine. I was told to check coil etc. but tonight looking at the service report the mechanic has put an extra 400ml of oil in the sump for me. 1.6l instead of 1.2. You mentioned a rebuild, have you had a look to see that the oil isn't the cause?

 

[Tafka]

Have made many oil changes after rebuild (i usually change oil after 10 hours).
Different oils, different amounts....

 

[Tafka]

Okay, changed the pickup coil as some recommended. But still no change...about one hour of riding and starts to act up as always.
So at the moment I can think of only two things left:
1) Try some other injector (chinese injector was crap)
2) ECU (something shitty going on there maybe? Visually didn't see any cold solders...)

 

[Tafka]

Hellllloooo....it's meeee agaaaain.
Okay...got used but working Ducati injector and things got little bit better.
First ride alone i had only few hickups but otherwise everything worked okay...i was happy at that point.
So today i went for a ride with friends and after few whoooops it started again....like misfire at low revsm slipping the clutch. At one point i just had to stop, it stalled. Started it again, fired up, little touch of throttle and stall again...and this continued many times, as soon i touched the throttle, it stalled.
So i started the bike WOT and got moving again. Worked decent for a while.
At some point it stalled again but not tooooo bad. So i rode the whole ride like this....somepoint works good, then again f**s my nerves.
Someone got matches?

 

[Yngvim]

Was looking at the ignition map and at 6000 rpm is the last value, is it running ok between 4 and 6000 rpm

EC 250 2001, FSE 450 2004

 

[Tafka]

Bike runs great above idle...if i can hold the throttle up at least 3500-4000 rpm, then everything seems to run great. But riding tight forest trails and considering i don't have balls to ride with open throttle then the problems start. So rev range about 2000-3500.
Slipping the clutch a lot but even then i struggle....get the revs up,slip the clutch, clutch engages, revs drop a little bit too low and it starts to skip beats.
It's not like stalling because of the low revs...that's little bit different.

 

[Tafka]

Anyone have any more suggestions?
Let's brainstorm....
What are the chances that ECU is bad? (then it wouldn't work at hig revs also...?!)
Too tight valve clearence? At the moment they are in spec (closer to the min. value) but maybe loosen them a little bit?
Crankshaft/connecting rod bearing f***d again? Symtoms are similar before i replaced the crankshaft/cylinder/piston but started suddenly and appear only when hot.
Decompressor spring too weak, so it starts to open exhaust valves at low revs? What are the chances of that happening? Decopressor looks working when moving it with finger but MAYBE somehow at low revs engages. How to check that?
Anyting else....?

 

[Yngvim]

Does it matter what map you run?

EC 250 2001, FSE 450 2004