450 fse 2004 help no start
 

Hi all, new to the forum and to the 450 only had it a short while, probably done about 150 miles with no problem, but while doing slow technical riding it stalled a couple of times and then refused to start, I thought I had flattened the battery so tried bump starting behind a car (a bit desperate I know) the engine didn't fire at all,
when I try to start it now, I get an occasional backfire from exhaust and the odd pop through air filter, seems like timing?
have a good spark, fuel pump priming, injector firing fuel, valve clearances to spec, cam timing correct, magneto still on keyway, I have read a lot about resetting Tps? my question is could there be any thing in the efi that could cause these symptoms?
In the meantime I am re-seating valves (slight pitting)as compression was at 90 psi, any help appreciated, thanks

How's your piston and crankshaft? I had similar problems when my piston was worn and crankshaft bearing went bad...
But try starting it with wide open throttle.
Also....go check/clean your injector.
I do not recommend messing with the TPS...at least for now.....try other things first. But leaking valves cause similar problems you have.

Thanks for that, piston and crank are good, I have put the head back on and still no start, but plug didn't look very wet pulled injector which is spraying, but I have found the fuel pipe is rotting internally, found black debris in the injector, so will replace pipes and clean injector and try again, thanks

I had similar problem, wouldnt work below 2000 rpm. Just backfired and stalled.
Turned out to be clogged injector. And the reason is that early models fuel pump strainer is rubbing into fuel tank and then allowing all the dirt to pass.

Anyone now where to buy only the strainer? Gas gas sells only complete fuel pump.

You can use car fuel pump....google a little bit and i think you'll find one that fits. Find your fuel pump code on the fuel pump. If i remember correctly, 2005 FSE has the same fuel pump as SMART CDI. I found one alternative, it works but needed some work/modification to the bracket that holds the fuel pump.
I installed Magneti Marelli pump with code MAM00081. (about $30)
NB! That pump diameter is larger than original pump so you need to cut/modify the plastic bracket!!!!!

Still no start
 

Hi all still struggling with the 450, engine all back together timed up precise, fuel injection tested and cleaned throughout, reset all parameters with guzzidiag ( no faults) I have come to the conclusion that the fuel and ignition timing is out because I only get a backfire when the exhaust is on so presume it is firing to late? I am now thinking Ecu, as the crank sensor is giving an rpm reading while cranking.
Has anyone else had this issue?
Is the Ecu timing adjustable?
Has anyone in the UK got an Ecu to try
Any ideas welcome thanks

Check the connector to the ECU. Are all the pins in place? I just had one FSE where some of the pins in the connector had dropped and not giving connection.
If the pins are ok then would the bike start with wide open throttle?
What's the voltage on battery when you crank?
Are all the connections ok?
GasGas EFI is very sensitive to voltage drops....if the voltage on battery drops under 10 volts, then it will not start.
When you assembled the engine, did you aligned the timing teeht on rotor correctly? 7-th tooth to pickup/pulser coil?

It sounds like it's one touth out on the crankshaft

EC 250 2001, FSE 450 2004

In Guzzidiag can you read all incoming signals and use all actors? If so I wouldn't focus on the ecu

EC 250 2001, FSE 450 2004

My fuel pump is still producing 3bar pressure at all times but my strainer is damaged and lets all the dirt through fuel pump ant injector.

I need the part that is near fuel pump in this picture. Did you used old gasgas strainer or adapted new one?
http://i18.photobucket.com/albums/b1...4/100_1079.jpg