Trophy 900 Cold Start Stress

ok so you have had it for some years now with no probs, I assume it has been serviced,airfilter , plugs good etc. the backfire and the bad starting suggest to me that the valves need adjustment, maybe this should be your port of call. but first, My Sprint starts easily every time, I leave my petcock on run all the time but if I havent used the bike for a while I turn it to prime, that is arrow up, and press the knob in for a few seconds, this ensures the carbs have fuel. then i turn my lights on for 5 seconds, apparently this spikes the electrics, no i dont understand either found on the RAT site). turn lights off, half choke and press the starter and off she goes. by the way I think your bike has carbs not fuel injection.

 

A couple of things, Drob.
Don't know what your tame mechanic meant re fuel injection as you've got carburettors on your bike. Perhaps he meant that the carbs can gum up if left for a few weeks without use - Redex or similar in the petrol will usually prevent this. He was right about the fuel tap though, just leave it in the horizontal position until you need to move it (may need 'prime' if the bike has been left standing for a while).
A good battery is essential on these bikes. Even though it will spin the engine there may not be enough power to supply the ignition system as well. The starting on my bike improved markedly when I replaced my battery with a Motobatt last summer (spun over faster and started more quickly).
Also, having the valve shims checked and adjusted as necessary improved starting (48,000 miles). May be worth checking if your mileage is near a multiple of 12,000.
When you move the choke lever does it actually move anything in the carburettor region?
Are you getting a spark when you turn the engine over? If not then that's a whole new can of worms to be opened!!
I guess fuel is getting through as the backfire is probably unburnt fuel building up in the exhaust. Or the ignition timing has slipped - highly unlikely though!
Hope this helps.

 

hay drob, this is the first best investment you can make if you own a bike, pays for itself.
http://www.ebay.co.uk/itm/Triumph-T...875249?hash=item1a0c5261b1:g:LJYAAOSwFqJWmQYO

 

To check for a spark, Drob, simply whip off a plug lead and push a spare into it. Rest/hold the plug body against the engine and spin the engine over on the starter button, preferably in half light conditions, and look to see if there is a spark at the plug. Repeat for the other cylinders, as there is a coil for each one. Some plug leads are easier to remove than others (a masterly understatement!) if the tank is still in place.
I have heard that this is not a totally 100% check as some plugs will spark in the open but not under the pressure inside a cylinder - apparently!
If you have sparks plus fuel, then starting should be possible - in theory!
I do remember a mate of mine buying a Trident 900 a few years ago, which had been stood for a while. When he got it home and started checking/servicing it, he found a mouse had been nesting in the air filter box. Just saying!!

 

hmmmmmm drob. that bit about the motobatt keeping it turning for 20 mins. short bursts are best I think,less chance to flood. you say your mechanic can start it so I would guess that is what you have done. remove the plugs and clean or fit new ones, how old are they anyway?? they could be fouled up. put new ones in is best. then try my starting procedure and see if it improves. the backfire could well be unburnt fuel igniting in the exhaust. if the mechanic cannot start it either I stand by what I said about the valve clearances, if they are too tight the engine will be a pig to start but make sure you have done the simple stuff first mate
is the choke working, on the left hand side of the bike next to the carbs, if you pull the choke lever does a lever move towards you,maybe it is stuck or broken cable,if it is tight lube it with wd40
whatever else you do, do not use the throttle when you try to fire it up, that will flood it definitely,leave the throttle alone until it is running.
battery 100%
silly I know but you do have fuel?? and it is not old as it may have gone off. I assume thereis no blockage.
prime your carbs first as i said earlier post
try leaving the fuel tap on prime, does that help,vacuum may be knackered ( dont forget to turn to normal on position after)

if you get it going I would suggest either redex or petrolmagic additive to clean out the jets in the carbs

for now that is something to look at,I am sure other knowlegable guys will give you more tho.
Good luck and persevere, they are worth it trust me

 

When you say it has been getting worse over time it makes me think of carbs and a slow build of grud, just a guess.

 

Check your choke cable again - mine had broken at the point where it joins into the self - adjuster.
Had a non- starting problem with the Enfield - was getting a spark as described above but only outside the cylinder. Turned out to be the plug cap on the end of the ignition lead which was knackered.

 

sounds to me like the valves have closed up. get the clearances checked. If the shims are below 2.5mm then the valves are on their way out. it is common for these bike to loose clearance on the inlet valves