ZXR intake

[sedge]

Hi all,

Would anyone have a spare intake restrictor thingy that goes in the airbox snorkel of a 91 ZXR750 J model ?... Previous owner had removed it and it wouldn't run past 7.5krpm. I'm duct taping the thing up at the moment but it's nowhere near the right aperture, revs out but is down on power and tapers off about 10krpm.

I guess the other option would be to ask if anyone knows what the right size hole would be to have in the intake ?.

Anyone ?

PPpppllleeeze.

Sedge.

[F5 Dave]

I'd be having a good look at the mains & needle position. Maybe the bike was sold with the pipe replaced etc etc. std vs 'fiddled' maybe?


Also check the needles haven't ovalised the jets which they like to do esp with Dynojet needles & a few miles. Need to have a good look at the needle jets removed from the carbs. (Or are they fixed in place in the ZXR?) The slightest ovalisation will be a bad thing.

[sedge]

Sorry, I didn't explain all that well in the last post.

It was running crap until I duct taped the intake, wouldn't pull past 7.5k, with the tape restricting the inlet it runs better but I'll have to try 9 million opening sizes to get it just right. At the moment with it half blocked I'm running OK, flatspotting all over the place, but it revs to 10k OK, after that it's carp...

I want to find out the 'right' size to smooth things out and not blow it up.

It's something to do with the CV carbs requiring a certain vacuumn in the box to work the sliders... It's a known issue if you remove the snorkel restrictor... Known by everyone except the people who remove it and can't figure out why the bike wont run anymore :/

Cheers,

Sedge.

[Two Smoker]

Yep i tried that on the ZXR400, it ran shit as hell without the snorkel, so i chucked it stright back in, maybe try a wreckers and see if you can get a second hand one???

[Milky]

And I did the same on my zxr400 and it is just as smooth as standard, but with a little more power throughout the range. I am sure it is also related to the exhaust harmonics/resonance... Something like that anyway.

[Skunk]

I want to find out the 'right' size to smooth things out and not blow it up.

It's not as easy as just the right size hole. I haven't seen a ZXR one but on the KLX there's a few different lengths and areas across the models (long and thin, short and fat).

Mine will only run with a long thin one. Runs out of puff at 6k with short and fat and won't run below 4k with one at all.

I suspect the same applies here.