Late model 225 probs.

[justcallmecam]

model: Yamahah F225
Year: 2010 (about 4-5 months old)
hours: 1060
Previous work done: usual servicing, faulty wiring loom replaced, low pressure fuel pump replaced, new gearbox after an encounter with some solid reef at speed, timing belt and tensioner at 1000hrs, rubber gromet on hp fuel pump replaced.

She was taken on a run for about 150k to nearest town yesterday and back this morning, went fine all the way in just under full throttle at about 5600rpm.
on the way back rpm has dropped to about 4900 under full stick, idles roughly shaking around and back fires a little under 1/3-1/2 throttle in nuetral or in gear.
plugs are good, firing on all cylindars, no info on gauges. fuel system was fully cleaned out when the gromet on hp pump was changed.

any help would be very much appreciated,
thanks,
Cam

[rodbolt17]

do a leakdown test to verify mechanical sealing abilty.
if that passes go fix the fuel system.
the backfire is most likly a lean backfire in the intake and is usually caused by low fuel pressure OR a clogged injector filter, each injector has a filter.

[justcallmecam]

thanks

I'm not equipped for a leakdown test out here, all signs were pointing at fuel system so ill start there, just didn't want to pull that vst out AGAIN..
thanks mate.

[justcallmecam]

OK

just pulled the VST out and for the second time the rubber grommet where the output of the hp pump goes into the top part of the VST has been split and pushed out.

this happened 5 weeks ago, i replaced it and it has run great untill now.

any ideas as to what could be causing this? I know i installed it correctly and it has happened before the VST has ever been appart.

My only idea is that maybe a releif valve on hp side is not operating? could this cause enough of a pressure build up to be moving to the next weakest link and blowing that seal\grommet out?

any input appreciated thanks

[justcallmecam]

just looked at the parts list, the rubber grommet i refered to they call a "damper".

[rodbolt17]

and thats why you MUST monitor fuel rail pressure.
if your going to do your own maint you MUST buy the tools.
no way around it.
there is a pressure relief valve for the high pressure and feed systems.
while the VST is off pull the injectors and check each injector filter and flush the fuel rails.

[justcallmecam]

yes i'm aware of thais and its something i have been telling my employers for some time now. to no avail.

is there some trick to removing the injector filters without damaging them or should i be chasing down a new set?

cheers

[mitch]

cam have you got a fuel pressure gauge and where are you mate

[rodbolt17]

easist way to access the injectors on an F225tlr,TXR, is to remove the airbox and flywheel cover, remove the VST,use the quick connect fitting on the fuel line crossover under the flywheel cover,dissconect the injectors electrical connectors then remove the 3 13mm hex head bolts that hold the rail to the intake. by carfully manuvering the port side rail the injectors can be removed from the rail.if the dampers and orings are in good shape they can be reused.
when reinstalling use a light oil on the orings.
stbd side, unbolt the rail, move electrical wires as nessasary and do that side.
whole job takes about 2.5 hours including cracking open the VST and cleaning that again,

[justcallmecam]

thanks guys, its back together and running well at the moment at least.

mitch i have one on order now, I'm at elizabeth bay, east arnhem land northern territory australia.