Trident 900 Aitbox replacement

steve lovatt · Jul 20, 2015

Finally got round to replacing the air filter on the Trident, having put the job off for a week or so. As many on this forum will know, this entails replacing the whole airbox assembly which is in effect a sealed unit. I know you can split them and fit a K&N filter but I went for a complete replacement.
It is a bugger - there's no way round that - tank off, hoses disconnected, throttle and choke cables disconnected at the bars, carbs off (slide out on LH side) and old airbox out. (and very little room to do it in). I also fitted new rubbers to the carbs and the box as the old were a bit brittle and cleaned out the two "witches hat" fuel filters in the inlet hoses.

Tips for puttting it all back.
1. Fit the crankcase breather pipe to the front of the airbox BEFORE you put the carbs back! (or you will be taking them off again).
2. Fit the carbs to the head first and tighten the clamps and then try (haha!) to fit the airbox onto the carbs. Warming the rubbers with a hairdryer finally did it for me and the use of a little washing up liquid.
3. When refitting the two halves of the throttle control and trying to keep the cable in place - note that the forward most half has a stud on it and the bars have a corresponding hole in them so it only goes on in one position.
4. Route your inlet and breather hoses properly when fitting the tank back on - make sure they are not trapped or twisted.
5. Best to label these when taking them off (masking tape works) see pics. You have two inlet, two breather and one vacuum pipe.

Good luck to anyone else trying this! Have cold beer ready!

Bike started first time and ran very smoothly on choke and dropped down to a nice idle speed. Great - so I thought - blipped the throttle and it stuck open at 5000 revs. Turned out the throttle cable was not routed properly and just needed twisting down wards under the throttle control housing. Check this before you ride!

steve lovatt · Jul 21, 2015

Update on the Trident since the airbox renewal - today being the first chance to ride it since the work was done.
Bloody amazing difference - it's like a new bike. Starts better, runs on choke better, idles smoother and pulls like a train from low revs, which it never did before.
Do this job if you need to, it is a pain but is is so worth it. The horrible rough spot at 2700 to 3000 revs has gone, which made the bike a pig to ride in town. It pulls all the way now instead of just from 3000 revs and is a pleasure to ride.
Work has got in the way for the moment but another trip is planned for this evening.

Keith Inglis · Jul 23, 2015

Steve, is the Trident any different to the Trophy ? mine is a 1992 Trophy 900 and I do not need to disconnect the carbs or cables to change the air filter, I do have to remove or lift the tank and remove side pannels for access, I just split the air box by undoing the screws around it and slide the back part back to the end of the slots and remove the air filter leaving the front part of the air box connected to the carbs and replace the filter, I fitted a K&N last time to save costs and everything is running fine, so I am a bit puzzled why you had to do all that to replace your filter ? but I understand you would need to, to replace the whole air box.
Keith

steve lovatt · Jul 24, 2015

Well the engine is the same Keith but not sure whether you get a bit more space on the Trophy to work with.
I did want to replace the whole airbox so, as you say, I had no choice but to remove everything. To be honest, having done it once I would find it easier to do a second time - and it's only every 24000 miles.
I have heard about splitting the box and fitting a K&N filter but I'm not sure I would have had enough room to move the box back and separate the two halves - perhaps other Trident owners have tried it and can confirm.
I read that one guy had split his air box down the middle - front to back - so he could juct pull one half out from the side - no idea how you would seal that though.