yzf missfiring help needed

[steve46]

???Hi all having problems of missfiring on yzf750 i have been advised that its the main jet blocked due to on low revs its fine? I am not confident enough to strip the carbs down myself. im ok with minor repairs but not that..If anyone can help i will be very greatfull im in Brotton
Thanks

[greenman]

ask mainjet mike he,s no1 on yams [ pms him]

[steve46]

Whats (PMS)?
I know what PMT is my wife has it 365 a year

[steve46]

Yesterday Today ;D Thanks to all, Greenman came around tonight found problem straight away he told me he has spoke to a few of you last night and i thank you all very much.
It was the exup it has seized, we managed to free it and open it up and she runs like a dream ;D
Can i leave it open without the cables on? will it run ok without?
I gonna take it out tomorrow, but im very imprested with all from the site and will hopefully meet you all at some stage soon at a rideout or meet.
Thanks Guys

[Mainjetmike]

Feb 24, 2010 21:57:53 GMT steve46 said:

It was the exup it has seized, we managed to free it and open it up and she runs like a dream ;D
Can i leave it open without the cables on? will it run ok without?

Im sure someone clever said it could be the exup.

With it wide open it will have no low down grunt though !

Have a +1 for owning a great bike , read my comments re M+S and the mighty YZF !

[steve46]

Im gonna try and free it tomorrow hopefully get the casing off and free it up but think im gonna have a problem releasing the bolts.
At the end of the day i done use much low down speed as most of us dont. It is a lovely bike as you say, goes like sh1t of a stick and handles so well..
Thanks to all and Greenman (diamond geezer) for his help

[Lee]

+1 for green man for going out of his way, +1 also to MJM for his input, steve, are we going to see a bit more of you on here then?

[steve46]

yeh be on here more often trouble is kids hog the computer been a member since november last year but been busy doing up my new house only just got around to sorting bike. I know i should get my priorities right but been living in building site and for some reason the wife dont like it, i dont understand her i work in it all week

[wildone]

Feb 24, 2010 22:59:02 GMT Lee said:

+1 for green man for going out of his way, +1 also to MJM for his input, steve, are we going to see a bit more of you on here then?

I've just sent this personal opinion to greenman --->>>

If you use it with the butterfly's wide open it will be as flat as a u no at the bottom end --- just like the original Genesis motor was.
The Exup was the biggest single step forward in progressive power delivery.
The best step is to do whatever is required to get the valve working -- in the meanwhile you (HE) will need to accept that his riding technique will need to be like a two-stoke / TZ rider --power is either on or off and riding below 4 grand is not recommended.

The other reality is that the motors are so fit that even when "flat as" they are still mega strong when compared to lesser units.

W1

In recognition that greenman insists that I always provide an illustration with my postings >>>



Close examination will confirm that the Exup valve is not working correctly in the port-side motor BUT the overall thrust is still sufficient for "normal " flying operations

P.S.
Those two white (bone dome) helmets may well be vexed by U - NO - HOO

[greenman]

Feb 25, 2010 0:23:17 GMT wildone said:

Feb 24, 2010 22:59:02 GMT Lee said:

+1 for green man for going out of his way, +1 also to MJM for his input, steve, are we going to see a bit more of you on here then?

I've just sent this personal opinion to greenman --->>>

If you use it with the butterfly's wide open it will be as flat as a u no at the bottom end --- just like the original Genesis motor was.
The Exup was the biggest single step forward in progressive power delivery.
The best step is to do whatever is required to get the valve working -- in the meanwhile you (HE) will need to accept that his riding technique will need to be like a two-stoke / TZ rider --power is either on or off and riding below 4 grand is not recommended.

The other reality is that the motors are so fit that even when "flat as" they are still mega strong when compared to lesser units.

W1

In recognition that greenman insists that I always provide an illustration with my postings >>>



Close examination will confirm that the Exup valve is not working correctly in the port-side motor BUT the overall thrust is still sufficient for "normal " flying operations

P.S.
Those two white (bone dome) helmets may well be vexed by U - NO - HOO

i am not getting close to that it will mess my hair up

[steve46]

Havant had a chance to get out to it today but have wd40 ed it again to help loosen up will be out there tomorrow.
Been stuck doing bathroom today.

[wildone]

[quote author=greenman i am not getting close to that it will mess my hair up :D [/quote]

O.K. greenman -- the faulty Exup is in clear view here --->>>

BUT --

You WILL need to wear your best helmet to keep your hair correctly coiffured

[steve46]

I have freed up the EXUP and is moving great but one of the cables have snapped and the other is thrayed So yeh pretty piffed off, have been trying to buy new but having no luck, if anyone can advise me where i can get them would be very appreciative.
The good weather is coming and she needs to be on the road

[maverick]

Would have thought petite and france would be able to get them no problem, ebay might be an option as i think they are about £35 apiece new.

This is the parts diagram for the RF, not sure how different it is to the R.

www.cmsnl.com/yzf750rf-1994_model10164/partslist/?q=yzf750