My Trike won't start - HELP!

Hello everyone. I have 1983 Yamaha xj900 trike, bought off of eBay after it had been in a smash along with all the parts necessary for a repair. As I'm not a mechanic and it wasn't a simple take off the old andreplace with the new job I took it in to a professional bike builder for the kiss of life and it came back running as sweet as a nut although the idle speed was a little high.
I have since taken off the tank & seat to wire in new lights for the rear as well as generally tidy up the electrics which were a bit of a mess, replacing the old fuse box etc.
Since I put it all back together, although the lights look and work great I can't start the engine. I have had it with a mate of mine for 2 weeks who owns a garage and he has been through it but can't see any faults. He has de gunked the carbs, checked fuel lines, filters, battery, connections etc etc etc but my baby will not go.
He had found a small white multi plug which apparently give off an electonic pulse when you try to start the bike but it is not connected to anything. I noticed it when I was doing the lights but guessed the guy who put the trike together must have done a bit of inspired electrics so left it alone. The bike was going anyway so I didn't worry.
The bottom line is that my baby still won't go and summer is 'almost' here. Does anyone have any idea what the spare connection might be (its hanging down near the connection tothe gear box and neutral indicator connector) or any idea of what we can check next to get me back on the road?
Any help, tips or advice will be appreciated as I am new to bikes and need to learn everything.
Thanks
Larry (flyingosca)
http://i200.photobucket.com/albums/a...eathome001.jpg

Sounds like a right drama,

1. Does the Engine turn over but not fire?
2. Do you have a spark from the HT Leads?
3. Are you sure you wired up the new fuse box correctly. Check for any wires that may be hanging loose around the fuse box area. ie you may have forgot/missed?
4. As the trike is based on the 1983 XJ 900, does the ignition system have an ignition coil? If so check voltage (LT) in and spark out (HT)

First things first, check all your fuses

Hi Bobthecod, funny I just saw you new posting re Licence to Ride. Good luck with that, I may pop in one day (when the trike is running!)
Yes engine turns over but won't fire, sparks from HT leads were a little weak but my garage pal did 'something' with the coils and apparently there is now enough zap to start the engine. It just won't!!
The fuse box only contained 4 fuses and all I did was replace the box/fuse holders and cleaned up the actual connectors new for old. I can't see anything else hanging loose. It is very frustrating. I am waiting for a Haynes Manual on the xj900 to arrive which has wiring schematics etc which I hope will shed some light on the problem. I just don't understand why it was running fine and all I did was remove the tank & seat, fix a couple of wires and put everything back and now it won't go - bummer!
Anyway thanks for your message and fingers crossed!

I know some of these are silly questions but sometimes they get over looked.
Have you got fuel in the tank??
Has the fuel switch been turned to off??
Have you trapped the fuel line when replacing the fuel tank??
Is enough fuel getting to the carbs??
Are the carb jets clogged??

Hi igbell
I think all the points you raise have been checked but I will go over them again. You never know!
I knoe the tank is at least 1/2 full and the switch is on, the fuel line runs under the tank, down inbetween a couple of air filters and into the system so no chance of anything getting trapped there. The fuel flow has been checked and the carbs are getting enough juice. I'll check on the jets although I would have thought they would have been checked when the carbs were cleaned.
I just don't get why it was running one minute and won't the next. Would it have anything to do with the idle speed adjuster which is down under the air filters??????

I had a problem similar to that at the end of last year. 3 out of 4 spark plugs just gave up on me overnight. Last thing i checked was that. Had a spark from the leads and as soon as i put a plug in the end nothing, changed plugs and vrooooom

It's 4 new plugs tomorrow!

4 new plugs went in as soon as it got to the garage. I've just managed to get the Haynes manual for the original bike, showing the wiring schematics so hopefully that will shed some light on the problem