Had this Thunderbird 900 for a few weeks now and it appears to suffer a problem with occasional fuel starvation. I am riding along nicely when there is a lack of power. I pull in and the engine stops. Wont start. After fiddling about with the fuel tap for a couple of minutes she starts up as if nothing had happened and i make it home with fingers crossed. This has happened three time in the last two weeks and when the engine is nice and hot. I dont seam to get the neutral light up when this happens,but I dont think it contributes to the issue. Any ideas anyone? Craig
A long shot I know but some filler caps have a vent in them that can become blocked. When you get the problem if you remove the filler cap is there a rush of air and does this help? You may have already tried this but I thought it worth a mention. Andy
I tried the filler cap. But did not notice any rush of air. The idea of a failing crank position sensor looks interesting. I measured its resistance yesterday and it was spot on. this could change when hot. However it does not loose power and stop every time it gets hot. Undid all electrical connector blocks and squerted wd40. Headlight was a sod.
the cps fails when hot.after cooling down the bike starts and behaves again,it is also an intermittent problem, I am not saying it is your problem,just another possibility
Hi Craig, careful diagnosis is the only way to establish what is causing your bike issues. For example there are several electronic components around the engine and all of these are known to misbehave occasionally in the manner you describe, breaking down when hot. Crank sensor is one but the ignition coils or igniters can also go tits up when hot. I'm not familiar with your engine but I would suggest you find a way of being able to check to see if you are still getting good sparks when the engine is hot.
Hi. I had this problem on my 1994 trident, turned out the fuel tap has a vacuum hose - this was perished and cracked, when the bike got hot the hose responded by opening the cracks enough that vacuum dropped and so fuel flow reduced/stopped until bike stopped. Does your fuel tap have rubber hose going to car by inlets somewhere ? Hope this helps someone in the future...
I think its a common mode problem as it affected all cylinders at the same time. Consequently, inruled out the coils. It feels like fuel starvation so first i am going to check the petcock and any filter it has, followed by changing the crank sensor. If that dont fix it ill cry as it likely to be the ignitor.
Check for vacuum line! Tight on all fittings and not perished, as fuel doesn't flow if motor isn't running or no vacuum because of leaks.
