Monday, May 13, 2013

exup valve

exup valve
 I have an exup valve and there is a fair amount of discussion on various forums on the subject of keeping or ditching the exup valve   Most expert opinion concludes that you should keep it.  After all it is there for a purpose and the variation in exhaust tuning that it provides does give real benefits on the road. If the exup valve cable freeplay is out of specification then you will encounter power loss above rough idling and poor throttle respo To adjust this you will first need to turn the ignition On then (do not start the engine) this will reset the servo motor and pulley.



                                                                 exup valve
Then remove the exup valve pulley cover at the bottom of exhaust see diagram exup valve White taxed to mar Mot aug. Only miles. Full service history approved red alarm loads of extras rg crash bungs  straight bars custom clutch cover and ignition cover custom alternator and radiator cover custom frame bungs and torque arm, custom tank pad rear hugger moto gp.
exup valve
I havent run into this issue and will likely mess with the exup valve on some spare evening to ensure that I dont. Thats an exceptional post Simon thanks for taking the time to do this.The cover of the exup valve is under the engine left side the bulging on the exhaust is the cover it can be taken off with a small ratchet no need to take off the side stand (as described in the manual).
exup valve
Many Check Engine warning lamps are caused by the exup valve failing to operate, in the case of my 675 this was due to the exhaust valve bearing seizing up. The exup valve first sign of this is often a loud squeak at start up as the exup valve cycles through its travel. Its quite simple to free it up yourself so here are some instructions.

exup valve
Stock engine exup valve removed rejetted filter one off polished stainless exhaust with cutdown Micron race can.The donor bike was a exup valve which I prised out of Herbie Lisk of Ballygowan for a pittance.Well it had to be really considering my budget for the whole project (including bike) was only exup valve.
exup valve

Stock swingarm deep braced and mirror polished one off  exup valve chainguard Talon gold alloy  tooth sprocket stock caliper Goodridge brake hoset orque arm mirror polished.Revealing a broken cable (yellow circle on pic left) The valve is in closed position no way you can develop serious power this way. Rotation in exup valve position is illustrated by exup valve. Dont wait for the tach to indicate exup valve Problems the rattling of the exup valve (to much slack in the cables) will wear the cables down in no time.
exup valve

the cables run from underneath the main seat. There is a servo that controls those cables. The cables run down the frame to the exhaust controlling the exup valve Once you take the cable out its open all the time and the exup valve the servo cant control it anymore. If you take the entire servo out theres going to be a light error. If you take just the cables out no error and exup valve stays open.
exup valve
I had to tidy it up enough to get it on a test ride to check the basics,and fuck me wot a dog.The exup valve servo and cables were missing (leaving a massive flatspot in the bottom end of the rev range) forks were bent with absolutely no rebound damping at all,steering head bearings wheel bearings and sprocket carrier bearings were all shagged chain and sprockets shagged The exup valve list was endless but bought it as seen and thought fuck it lets just get stuck in  exup valve The clocks having the total guts of the original exup valve ones .
exup valve
Aluminium inserts were made for the top yoke so that it would accept the exup valve new risers and the whole lot polished.exup valve The gearing of the sprockets was changed  for more acceleration and the jetting changed and a filter added to try and overcome the flatspot which with the difference in the length of the pipe got rid of about
Finally a bellypan off Tommys old Gixer fighter was offered up,brackets made and bolted into position.exup valve Then came the painting,my mate Tommy Cathcart stepped in again and laid it on flawlessly on both exup valve the wheels and bodywork.Goodridge hoses were added all round and stainless braiding applied to all the water pipes.
exup valve

The name exup valve was thought up by my old son Clark.exup valve is a term not on the a has, the "exup valve serves a different purpose and if you think about it, its much further up the exhuast, closer to the head, the exup valve on the is more about noise control than it is about low end power management, not saying it has no effect on bottom end, but much les of an effect as the yamaha valving, at least the earlier systems, as thats what i am familiar with.
exup valve
 About a month of owning this bike some nice box pilot decided they wanted the same space of road as Mike and just hit him. Long story short. Mike got himself off work for about  weeks with a broken clavicle (a shoulder bone to you and me) and a slightly roughed up exup valve . Being a slightly superstitious fellow he decided to sell on the bike that saved his precious Gixerexup valve.