2k idle?

[kiwi cowboy]

87 fzr750 that I bought and had a few problems with including (I felt) not pulling or running right.

Maybe a bit wrong of me to say that I thought as the guy I bought it off said it had a heap of money spent on the carbs when he bought it but after some of the other problems I had that the shop should have noticed for a warrant im not surprised what I found.

First I noticed after taking the tank off was one corner of number 4 throttle body where the diaphragm screws too was broken and had a crack where the glue had not held.
Ok cant really blame the shop for that cos I don't know it was them or not.

Took a bit to get the diaphragm tops off to raise the needles one notch with the screw heads rounded and whoever did them up was hamfisted.

What I can blame on the shop if they did work on the carbs was what the fuck was a 15x7ml spring doing floating around inside the cap of number 1 cylinder between the diaphragm and the cap effectivly jamming it from letting the slide rise up..

Anyway i have put it back together and wow what a difference it made some how cos its a lot smother on the power and wants to rev buy will only go back to 2k idle.
Took the carbs off and checked the idle screw and set them 2 turns out by the book ( they were 3 turns) and made sure they were installed with no air leaks but no difference.

Any ideas would be good?.

The only thing I can think of is the carbs need balancing What do you guys think?.
I have checked the idle screw if not the problem and the throttle is lose and letting the butterflies go right back.

Cheers KC

[unstuck]

Can you adjust the mixture at all on your carbs? Is it sucking in air around where the throttle body is cracked?

[kiwi cowboy]

Can you adjust the mixture at all on your carbs? Is it sucking in air around where the throttle body is cracked?

The mixture is the pilot jet 2 turns out but was 3 with no difference.

Don't recon its sucking air where its cracked with it redone with kneedit its better than before and wasn't revving before.

[unstuck]

No backfiring or popping?

[kinger]

Has it got a manual choke?
Idle adjustment knurled knob, left hand side of bank?
(Seperate suggestions)

http://www.fzrarchives.com/ipb/index.php?showtopic=8141

[kiwi cowboy]

Has it got a manual choke?
Idle adjustment knurled knob, left hand side of bank?
(Seperate suggestions)

http://www.fzrarchives.com/ipb/index.php?showtopic=8141

Yes to both and the chock is right off and the idle adjustment is backed right off.

I rang the shop that worked on it and was very interested in what he had to say.
It seems that after they worked on it the owner and some numpty fucked around with it so god knows what is set up so might try to synk carbs first cos when I start it today it sound as if its not firing evenly at idle of 1500 revs and evens out at 4k above with throttle so could be carbs way out of synk.

[kiwi cowboy]

No backfiring or popping?

No backfiring or popping but sounds a bit like its got a lumpy cam at idle if that makes sence lol

[unstuck]

Pilot screws have not been screwed in to hard, and left a wee groove in the tips? Sync sounds like a place to start though? Good luck chap.

[kiwi cowboy]

Pilot screws have not been screwed in to hard, and left a wee groove in the tips? Sync sounds like a place to start though? Good luck chap.

Cheers mate,
Possible its shit in the idle jet too as I have another tank coming as mines a bit shitty but if all else fails we do need some flood protection anchors in our river after the rain and snow

[Hoon]

Do the easy stuff first and check for vacuum leaks. Spray the suspect areas with CRC while it's idling. If the revs change then you've found it.

[Drew]

Do the easy stuff first and check for vacuum leaks. Spray the suspect areas with CRC while it's idling. If the revs change then you've found it.

I use engine start for this task. It's thinner and gets sucked in easier.

The FZRs are real sensitive to float bowl height. If ya do a stoppie on one, you have to fuck around for a couple minutes to get it going properly.

If it runs mint with any throttle on, I would try and balance the butterflies first. Old school with a piece of hose held up to your ear, and the other end sitting at the inlet for the carb and the bike running is pertty accurate.

The last owner may have opened the carb you described that had the extra spring, (come to think of it, the spring you described might have come from between the linkage/butterfly actuator thing between the carbs. So have a look at that too. Should be one on both sides of the tab with the adjuster screw locating one), and now that it's gone it's too far open.

[Hoon]

I use engine start for this task. It's thinner and gets sucked in easier.

No the aim is to temporarily seal the leak with fluid, not aid combustion.

[Drew]

No the aim is to temporarily seal the leak with fluid, not aid combustion.

It's almost 100% going to suck in some ether and rev a bit higher briefly my way, but might not seal the leak your way is my only argument.

[kiwi cowboy]

I use engine start for this task. It's thinner and gets sucked in easier.

The FZRs are real sensitive to float bowl height. If ya do a stoppie on one, you have to fuck around for a couple minutes to get it going properly.

If it runs mint with any throttle on, I would try and balance the butterflies first. Old school with a piece of hose held up to your ear, and the other end sitting at the inlet for the carb and the bike running is pertty accurate.

The last owner may have opened the carb you described that had the extra spring, (come to think of it, the spring you described might have come from between the linkage/butterfly actuator thing between the carbs. So have a look at that too. Should be one on both sides of the tab with the adjuster screw locating one), and now that it's gone it's too far open.

Thanks for the advice drew and hoon.
I took it for a quick ride tonight and it does run good on the throttle so will check with crc as that's what I have in the shed and have ordered some clear hose to make a balancer for the carbs cos my hearings shit lol.
It actualy sound like a Subaru when ideling a 2k when hot but as soon as you throttle on it evens out.
Has improved since last time out though but has a flat range between about 6-7 k

[Drew]

It actualy sound like a Subaru when ideling a 2k when hot but as soon as you throttle on it evens out.
Has improved since last time out though but has a flat range between about 6-7 k

So it's not firing on one cylinder at idle. Those motors are fuckin noisey when they're not running smooth, partly because they run a bloody great gear driven alternator instead of a stator/regulator rectifier.

It's all a bit hard without seeing it, I'd be looking to see if that little spring didn't come from where I think it does, then I'd be looking long and hard at the cracked diaphragm cover. Any air getting above that, completely fucks the way a CV carb works. If it hasn't got more pressure in the surrounding atmosphere than above the diaphragm rubber, it won't lift the slide.