Hi folks, Not sure what to call this thread, hope one of you guys can advise on my old 900ss problem. The bike has suddenly developed a problem wher she strarts OK but then intermitently cuts out when opening the throttle from idle. Then wont start and backfires. Just been on a run on her tonight, all good full throtle up and down the gears for an hour, came to a set of lights went to pull away.....she died!! couldnt restart!! Very awkward!! Ive had the carbs of, stripped cleaned and put back on, still the same, any suggestions or similar experiances?? Got back after run tonight and engine was running fine. switched her off...she wouldnt restart. Just been out after a couple of hours and she started fine ( wife came out and told me to stop!! to noisy ) any advise apprieated, cheers, Billy
hard to diagnose over the net but sounds like it could be electrical loose wire on ignition switch ? or dodgy kill switch are popular faults or a loose wire somewhere else
Hi Billy Have you checked for air leaks on the inlet stubs , are the balance blanking screws still there ? are the carbs balanced, if you need some vac guages, i have some mercury ones. let bob know at work, or come and see me in 302. The ignition kill switch would be the first place i would be looking at, can you isolate or bypass the circuit ? hope you get it sorted, as this weather is too good to miss. fergus
Fergus, Its a stange one, unfortunatly its intermitant. Ill have a look at the kill switch tomoz, but wuy is it happining at idle?? I had it out on a run tonight and it was running like a dream, untill I got to the lights at squires gate, opened the throttle and it died, and would not restart, had to wallk it to the side of the road, got it restarted and it was fine. If ye fancy a visit to st annes to have a look yer mmor than wecome!! I dont fancy riding her out again. cheers billy
Sounds like a vacuum problem to me...........half fill the tank and go for a run on it with the filler cap not fully closed......say five miles without chucking it about too much.............I bet the breather valve is blocked.
Check your ignition coils. Could be they are on there way out, when they are cold/cool, engine starts, after a run and you pull up and idle they are over heating and stop working, wont start until cool enough and starts again, sounds like they are braking down, check them with a multi meter with reference to manual or if you have a mate with same bike do a coil swap. another idea check valve clearances when cold starts went hot wont start, fuel evaporating due to heat. just some areas to look at.
got a set of coils and leads if you want to try them, these are the standard coils from my bike,i upgraded them a couple of years ago. fergus
As already said, it could be many things going by the symptoms but it does remind me of an over-rich mixture at idle often typical of a Dynojet set up, particularly if it's a stage three kit on a standard engine.
Ref the coils ..mabey who knows with these old bikes!! I put new coils on last year the red ones cant remember where from now, however ive also had the start up problem from cold the neighbours must hate me with the sound of the backfires!! Yet ones shes running shes perfect. Mabey its time for her to retire!!
Fergus, Ive got new coils on the bike myself, and still got the old OEM ones and leads, its got me beat for now!
is it when its warmed up? could be the pick ups failing (common on 600 bikes) and it tends to be intermittent and symptom as if running out of fuel Or choke stuck so too much fuel. or a blockage of filter stopping enough fuel? or split in the rubbers letting in air?
had a problem with my old 900 ss years back. Would run fine then all sorts of bother every now and then. Turned out to be a large amount of water in the tank. It lived outside and had a leaking fuel cap seal so over time water built up to the point where it reached a level where it could be sucked up. I drained the tank expecting to find crud but found best part of a liter of h2o
It would help if you could add more symptoms/what you have changed or looked at already, e.g. How are the plug colours, are they the standard plugs for the bike? Meanwhile a search via Google using "900ss won't start" brings up a good half hour of reading. Ducat.ms is often the best source of information.
Hi, she wouldnt start this morning, massive backifire!! Neibourors love me!!, So, ive cheched out the voltage to the igniion units all ok kill switch all ok, its not water i fuel ive emptied tank and cleaned, had the carbs off cleaned back on, checked compession ...fine 140-150 psi both cyliders, plugs look fine, now shes ruuning and starting fine, also i checked the pick up resistance ...98 ohms each , its got me beat!! New bike time!!
Update on the bike, it was the sparkplugs. simple fix, after messing about looking at the carbs, it was actullly a basic fix ...new plugs...ive changed the oil plugs and fuel filter, and shes running like new now, ive put in Mahle Fuel Filter KL145 (BMW) -single SKU: 00069867 1 £12.04 Castrol Power 1 Racing 4T 10w-40 Fully Synthetic Motorcycle Engine Oil -4 Litres SKU: 00000955 Safety Data Sheet: Castrol - PDS & MSDS Search 1 £33.29 NGK DCR8EIX (3606) - Iridium IX Spark Plug / Sparkplug -Single Plug SKU: 00079296 2 £12.42 Put the plugs in first and that cured the problem
glad you got it sorted spark plug failure seems all the more common these days with resistors in spark plugs failing had a few issues with new ngk plugs over the years got some bosch ones in the the bike and they have been great so far
