Thanks for the ongoing support on this I'm going to re-clarify everything in this post to try and get some advice for next steps. 1) Everything has been working fine, I parked at the pub got back on and then immediately noticed it as I rode up the road. Throttle would only open about 1cm. 2) Casting my aged mind back I do remember the bike not starting properly and shutting off quite abruptly. But it started again fine and then as I rode off I noticed the throttle issue described in 1) 3) On stripping it all down it had the issue right through till I removed the airbox, the action still felt stiff and a bit sticky so that's when I cleaned it all out and lubed it all and sorted it. The throttle all works 100% with the airbox off. (in hindsight this was just a good service for all the linkage and cables and was a red herring for the actual issue) 4) on refitting the airbox it's the same problem described in number 1) again and now I can see the airbox flexing on the right hand side where the top linkage from the throttle is pushing against it. I've not had any time to investigate anything further but either the throttle linkage has risen up or the air box has dropped down is my laymans summary. The bike has absolutely no signs of damage or being dropped anywhere it's immaculate for it's age.
Ok so it is this. I checked everything and the air inlet valve (is that the correct description?) is sitting up out of it's rubber sleeve, you can see the gap highlighted in this pic. Is this something you just undo the jubilee and reseat or is it more complicated that that, and why would it move up in the first place ?
sorted by the looks, I was about to add other reasons why trumpets weren't aligned (I posted in detail earlier but you may have missed it?) but didn't want to overwhelm you.. nrsntt. I remember a similar case when brace between throttle bodies became loose causing similar results. Definitely need to check the other body to see if it's in place/jubilee tight followed by a thorough general bolt check.
Just to follow on from @Chris, my bike was lowish miles (10k) when I bought it in November and the amount of lose nuts/bolts I have found is unreal. The whole subframe was lose. Worth an hour or 2 checking all the bolts with some thread lock.
Thanks @RickyX but just as a footnote - I am not nearly eagle-eyed enough as you can see the body is displaced in @Fastmonkey s photo in post #22! :smile:
We had ridden some pretty lively b roads that night. The lovely jubbly was pretty lose on inspection, the front one was nice and tight but I nipped it up just in case. re-seated it and re-fitted the airbox and the throttle is snapping shut like a dream. Tank next.........
It was ok when you got to the pub but not when you departed. Did some piss head at the pub knock your bike over?
A backfire can cause the injectors to dislodge, see below from a previous post of mine in this thread, I've seen it happen before. "The airbox should easily clear the throttle linkage, I can only think that a blowback or loose induction injector to stubs have caused the the injectors to rise up and foul the linkage. I would check to make sure the injectors sit on their stubs correctly and then follow the action through to make sure nothing is sticking."
it wasn't an injector though, the whole rear throttle body had popped out of it's rubber tubular inlet mount. (see above picture).
That was actually what I meant, I think I should have explained more clearly and maybe that may have led to diagnosing the problem earlier. I have just done a 748 the other day with a loose "injector" at the front where it had blown out of the inlet stub.
Well you were on the right wavelength Red998 just took me a while to work it all out. When you don't know the terminology of all the exact bits and pieces it's hard to follow everything exactly, just needed to get there myself, it wasn't until I thought I'd fixed and refitted the airbox that I then twigged that something had moved. However I now have a fully serviced, cleaned and lubed throttle linkage, cam and cable with the correct adjustment and a fast idle button that now works, so that's a bonus ! I think it happened when I started the bike after the pub, it did behave a little strange but I can't remember exactly what happened but I want to say it was a whoosh/woof type sound when it conked out which might have been a blow back and as the jubilee was loose, dislodged it. So what causes blow backs then ?
Apologies I should have been clearer, but at least you got there. Backfiring when riding along can be a sign of a weak mixture. If it backfires on start up then it could just be down to a misfire which blows back through the intake. I know several bikes that regularly backfire through the inlet and normally it's not a problem. All should be fine now with any luck
