update: took the plugs out and grounded them on the engine, sparks ok. Any ideas on the best way to test fuel flow?
Just because the spark plugs spark at atmospheric pressure doesn’t mean they will spark in a damp 14:1 air fuel mixture at over ten times that pressure but if the plugs are new, have the correct gap and are fitted correctly its unlikely to be a plug related issue.
To check the fuel flow rate without a fuel flow meter and assuming the fuel pressure is within specification c50 psi. First check battery has a good level of charge (>12.5v) and charge if necessary. Check manufacturers specification for fuel flow, which might be expressed as something like ‘189 cm3 (6.4 US oz, 6.7 lmp oz) minimum/10 seconds’. Use whatever scale you’re comfortable with and check the pump is pumping that amount of fuel within that time frame by collecting a measured sample from the fuel line. In the example above I’d expect to collect a minimum of 190 ml of fuel in 10 seconds.
You may also want to check and test the spark plug and coil pack HT leads. If the resistance per meter is printed on the side of the HT leads go with that, if not assume it’s 15,000 ohms per meter. Set the multimeter to 20,000 ohms and connect one probe to each end of the lead assembly to be tested and measure the resistance. While testing, gently twist and stretch the lead and if the reading doesn’t fluctuate and stays below 15,000 ohms per meter then the lead should be OK. Note resistance is proportionate to length, if length is halved resistance is halved. Repeat the test on all HT leads and don’t forget the coil pack leads. Also give each lead a visual inspection for any damage. If any lead fails the resistance test or is found to be damaged in any way best practise is to replace the leads as a complete set.
You may also want to test the ignition coil peak voltage and/or the crankshaft position sensor. Which, assuming the battery has a good level of charge, is probably where Matt was going with the speculative ‘cranking with insufficient amps’ diagnosis.
Another idea: it’s been suggested to spray a bit of WD40 down the bores to dry it out but I’m not so sure that would work with petrol? Any ideas/experience?
if it does fire up it will smoke abit & could kill the catalytic converter
Another idea: it's been suggested to spray a bit of WD40 down the bores to dry it out but I'm not so sure that would work with petrol? Any ideas/experience?
me_groovy
have you tried to give a sniff of easy start,
nope, this the stuff? http://www.halfords.com/motoring/engine-oils-fluids/fuel-oil-additives/bradex-easy-start-300ml Think the wd40 suggstion was based on it being more available
Big clue in the description
It is designed for use in an emergency where the engine won't start, which could be caused by a number of different ignition problems http://www.halfords.com/motoring/engine-oils-fluids/fuel-oil-additives/bradex-easy-start-300ml
Fix the problem ;-)
yep
nope, this the stuff? http://www.halfords.com/motoring/engine-oils-fluids/fuel-oil-additives/bradex-easy-start-300ml Think the wd40 suggstion was based on it being more available
me_groovy
After further testing and checking the diagnostic codes, I’ve found it does nothing different if I unplug the immobiliser. Ponderous.
Update: sent to a recommended local mechanic. he can’t find a problem so he called in an electrical specialist who also can’t figure it out. seems the injectors aren’t being sent the pulse to open by the ECU. If the ECU is buggered then it’s paired to the keys so I’ll need a new lockset as well. £1200 for that.
Blimey. How might you have ruined the ECU?
For most things, yeah :) I've definitely suggested Easy Start to you before, it's an excellent go-to when an engine's not starting. It doesn't sound like it's that useful here any more, but if you can get the bike started on easy start then you've demonstrated that it's all working, just not well enough to start. If you *can't* get it to start on easy start then you've an actual problem.
nope, this the stuff? http://www.halfords.com/motoring/engine-oils-fluids/fuel-oil-additives/bradex-easy-start-300ml Think the wd40 suggstion was based on it being more available
me_groovy
Also good for cleaning things and making firelighters.
exactly my thoughtsnope, this the stuff? http://www.halfords.com/motoring/engine-oils-fluids/fuel-oil-additives/bradex-easy-start-300ml Think the wd40 suggstion was based on it being more available me_groovyFor most things, yeah :) I've definitely suggested Easy Start to you before, it's an excellent go-to when an engine's not starting. It doesn't sound like it's that useful here any more, but if you can get the bike started on easy start then you've demonstrated that it's all working, just not well enough to start. If you *can't* get it to start on easy start then you've an actual problem.
Also good for cleaning things and making firelighters.
Big Red S
Gulp!!
Sent the bike to the Yamaha dealer I bought it from. They’ve diagnosed low compression and think it might be the valves are out of spec. She’s just shy of 24000 miles, which is when the valve service is due so I’ve agreed for them to do that. They have confirmed that fuel is getting through the injectors though.
Valve clearance service has been done, still low compression. Should be 160psi and is 50-70psi. Could be head gasket, could be cylinder damage but they are sure it’s damage from overheating. There’s one 2nd hand engine on ebay for £1500, it’s either that or scrap it. Bike’s maybe worth £2000, if it worked.
Of course there’s a 2017 engine for £600, but typically that won’t fit my bike.
Fucking hell! That’s a 3yr old bike?!
Are all the cylinders showing low compression?
yup
must re read posts as forgot the reason for its repair and not being an isolated issue .sorry.
Bloody hell, that’s not good.
Have any other of these bikes had the same issue?