hi, Just wondering is there any way of telling that the stator is not working. Its just my bike wont start at all , there is a spark and i changed the spark plug. I checked the fuel pipes to make sure none of them are blocked, the fuel filter looks like it may have a bit of dirt in it but it was like this when i got the bike back, it was starting fine. The bike would often back fire, making me think the stator has finally gone. The bike has been sitting a month or two. Any advice would be appreciated, many thanks.

Backfiring and non or difficult starting is often a sign of a faulty HT coil, an easy item to test or swap with a known good one.

Thoroughly clean the filter, airbox, tank and carb and use new fuel. Water in fuel can cause these symptoms.

My next move would be to check for a sheared or part sheared ignition flywheel key.

The TRS stator is a different set up to most bikes - is there a hole in the casing where you could put timing marks on the flywheel and check the timing with a strobe. other than that all you can do is check the stator outputs (source and trigger) at the wires outside the case whilst cranking the engine.

 

Edit - If its a Sherco then you can remove the ignition case to put timing marks on flywheels and spin flywheel with a power drill both to check timing and stator outputs.

Edited June 25, 20179 yr by dadof2
As noted - not sure which bike

sorry forgot to say its my 2011 sherco 290

You stated that you do have spark, which is a good sign, however if it is occurring at the incorrect time the thing will not start.

 

Get a flywheel puller an remove it to inspect for a sheared woodruff key on the shaft, or take it to someone who has the stuff to do it properly as it requires special tools for the procedure.

Woodruff keys are often the problem on sherco 

Ok thanks for the advice i really appreciate it, i will probably have to take it to my dealer as i have never done this before.

Ok got the bike started, i drained the fuel tank and washed it out and connected the tank up, then i filled it with fuel and kick it 20 times then left it for 10 minutes started first kick but opened up full throttle. I found out the cable connected to the top of the carb had been pulled out of it position. I havent started it yet but hopefully it should be ok.

I had similar problems on my very old Sherco sometimes taking ten+ kicks starting, sometimes not and the throttle being tetchy, backfiring, overheating etc.

Was worried the stator had gone, but eventually pulled the flywheel after advice here (tenner for the flywheel puller), the woodruff key had completely sheared - a couple of quid from Splatshop.

It's and easy job if you have the tools  

 

 

Ive got a 2005 sherco 450 it starts and runs on tick over as soon as u try to rev it it just cuts out fuel and spark are ok anyone got any idea please 

10 hours ago, dunk10 said:

Ive got a 2005 sherco 450 it starts and runs on tick over as soon as u try to rev it it just cuts out fuel and spark are ok anyone got any idea please 

Have you ever adjusted the valve clearances?

On 7/27/2023 at 3:00 AM, dunk10 said:

Ive got a 2005 sherco 450 it starts and runs on tick over as soon as u try to rev it it just cuts out fuel and spark are ok anyone got any idea please 

Got it to rev but it just back fires like hell yer its been reshimmed but bike been stood for over a year rode it up road it konked out now it will run on tick over all day but wen it revs it back fires pops and bangs even made exhaust go red 1

hell yer its been reshimmed but bike been stood for over a year rode it up road it konked out now it will run on tick over all day but wen it revs it back fires pops and bangs even made exhaust go red 1

2 hours ago, dunk10 said:

Got it to rev but it just back fires like hell yer its been reshimmed but bike been stood for over a year rode it up road it konked out now it will run on tick over all day but wen it revs it back fires pops and bangs even made exhaust go red 1

Do you have a service manual?  

You described lean operating conditions and the bike is fuel injected.  I assume the air filter is clean and correctly oiled with no obstructions, no mouse nest in the air intake.  Next suspect would be sensors, starting with an oxygen sensor assuming it has one.  Check your fuel pressure because low fuel pressure could be a cause, check the fuel filter itself for damage and all the hoses attached to the filter for splits or leaks.  The injector could be the source of the problem, but I would check all those other things first.  

 

@dunk10 I found a service manual, no oxygen sensor.  I recommend you do a fuel pressure test, the Sherco manual shows that you need a pressure gauge to do that and you are looking for 3 bar which is equal to 43.5 psi   

If you don't have a pressure gauge I know you can also test fuel pumps by measuring the fuel volume output.  For example a Montesa fuel pump which operates at similar pressures (33 to 46 psi), when connected to a 12 volt battery the pump will move   0.749 l/min (125 cm3 / 10 seconds)