hi can any one help i have got a k plate yzf750r that won`t rev over 4000rpm while moving and sounds like it is hitting the limiter it coughs and spulters but if at a stand still it will rev right out has any one had this prob before or knows what it could be it was running fine before and just went all of a sudden

exup valve at a guess, check the cables make sure they arent seized

Yep sounds like that to me

hi can any one help i have got a k plate yzf750r that won`t rev over 4000rpm while moving and sounds like it is hitting the limiter it coughs and spulters but if at a stand still it will rev right out has any one had this prob before or knows what it could be it was running fine before and just went all of a sudden

Hello. I´m new at this forum. I have the same problem as You describes, with my own YZF 750. Had the bike in a workshop in Molde, and the mechanics had never heard about a problem like this. All cables in the ignition system, the coils, spark plugs etc was contolled, and the mechanic concluded that it had to be the CDI-unit. But when I replaced the CDI-unit, it was all the same. Have You found out of this problem. Sees You were told it could be the exup valve. Please tell me if You found out of it.

90% chance it was the exup valve. Take off your lower fairing and the little metal cover that protects the cable mechanism on the exup valve. Then take off the cables, and turn it with a pair of plyers a few times whilst spraying with some silicon spray and this should sort it. If its not just the flap which is sticking, force some cable lube down the cables from the servo under the seat whilst the lower cables are still disconnected. And keep moving them in and out.

One way to stop this is buy a nice

set of stainless down pipes and

race can.get rid of the exup valve

all together o and give yourself a

few more horses!!!

One way to stop this is buy a nice

set of stainless down pipes and

race can.get rid of the exup valve

all together o and give yourself a

few more horses!!!

and no mid range or bottom end

and no mid range or bottom end

Thks for quick reply. I have not had a chance to try out the tip abowe, but I guess I´ll have to take a trip in my garage this afternoon, after kids bedtime. If this is something which will give me lots of headace I might vil change the wole exhaust-system with one without exup-valve.

I bought the bike (cheap) last spring, with some damage, but onely on the plastic (fairing), and I am building it to a streetfighter.

Rgds

Theres a lot of serious tuning involved to get the same lower end torque if you remove the exup valve though. Of course it can be done and some real gains made but the money needed prob best to buy a 1040 kit.

Never had any probs with mine in that department

Just take of cables and most important leave the

sevo wired up and a KN filter and then

little bit of dyno work and its fine.........

Thks for all help. Took me an hour last evening. Demounted the cover who protect the wiring on the exupvalve, and the "wheel" which the wiring is fastened on, was loose. After tightening up the screw who holds it, everything worked fine. Sadly this years season is finished. Guess the winter will be used to finish the streetfighterproject. Thks again for all help.

got a full race system in me shed with shot gun cans (no exup)

set of carbs stage2 jets

and a air box with a K&N in her.

she was close to 115bhp

£150 the lot

thats a full stianless

http://cgi.ebay.co.uk/yzf750-yzf750r-full-...1QQcmdZViewItem

Hi again, and thks again. Just been out for the last trip this year, onely for testing. Was raining cats and dogs, and the front fender is disasembled. Yesterday it was snow on the roads. Guess if I was wet, but it was fun anyway, when the bike is working OK at last.

Attn. Sheeny7

Thks for the weblink. Have allready made me an account on the streefightersite. Lots of nice pictures. Guess it is possible to get some ideas there. And a few tips if I need.

Attn. Barden

The race system You have, how old is it, and is it in nice condition? Schratches/bulbs etc. Do You have pictures of it, both mounted on the bike, and disasembled?

hi can any one help i have got a k plate yzf750r that won`t rev over 4000rpm while moving and sounds like it is hitting the limiter it coughs and spulters but if at a stand still it will rev right out has any one had this prob before or knows what it could be it was running fine before and just went all of a sudden

I had this happen once,

I fitted a micron end can.when it was a cold day it would make the bike run lumpy and when you revved it the bike souned like it had a miss fire.on a warm day the micron works fine

so I changed the end can and the problem went.