Upshotknothole

Depends on the jet kit, dynojet plugs them, factory pro doesn't.

Took it out for a ride, still bogging, but it feels like it's moved lower in the power band now. Made the bottom end even more gutless. What's annoying is I have a spare set of RS38s sitting on a shelf right now that part of me really wants to try putting on, but I know they're way too big for this engine and will make it horrible for riding around town...though I may still try one day while waiting on RS36s.

Yup, a new factory pro jet kit and stock emulsion tubes and I'm already looking at almost half the cost of a set of RS carbs. Some of the rubber bits were also showing their age and the carbs could use a rebuild kit. Easier to just throw new carbs on. Plus my first slingshot had them when I got it and I always loved the way the top end hit on that bike.

Go introduce yourself in the general section, and post up some photos of the bike. The hoses between 1&2 and 3&4 are vent lines.

The needles are already lowered all the way or close to it. This whole jet kit looks pretty old and tired, if I had time I’d throw a factory pro kit in there and replace the emulsion tubes with stock, but leaving for a road trip next week. I think I’m also going to switch to RS36s after I get back and not bother with these carbs anymore.

Went through the carbs, the tips of a couple of the needles were slightly bent, the dynojet needles are really thin at the tips, straightened them a little, emulsion tubes look a little oval, but the float bowls were really clean, just a tiny bit of dirt in the bottoms. Gonna put in fuel filters, ditch the aftermarket single outlet petcock and go back to a dual outlet stock unit. A couple of the single pod filters were starting to come apart, putting dual K&Ns on. Replaced all the plugs, I think 2 or 3 of the caps, and one of the coils as the leads on the 2-3 coil had been trimmed to the point that it was stretched tight over the breather cover going to #2. Whichever previous owner of this bike used anti-seize on the coil screws, I could fucking kiss them. I was expecting to be cussing all evening trying to get those horribly soft screws out. Should have it back together tomorrow and hopefully it runs a little better. I haven’t dealt with CVs in a long time and I don’t miss them. I think this bike is getting RS36s later this year.

3 out of 4 leads pulled right off the spark plug caps, and the plugs are far from uniform. Gonna swap out the leads, caps, and plugs.

When the mid range started to bog I hadn’t changed anything. So it very well could be some crap in the carbs. I’d only had the bike a few months and I’ve probably been riding it a lot more than the last guy. The tank is pretty spotless, but I have yet to crack open a float bowl to see how much varnish is in them. All I’ve actually done with these carbs is pull the cap off one to check the needle and noticed they have a dynojet kit. Gonna pull the carbs tomorrow and go through them. The bike pulled pretty strong through all the revs when I first picked it up earlier this year.

The needles didn't have any grooves in them, but they did like kind of warn. I'm almost positive these have a dynojet kit in them so I'm gonna check my spare set of BST38s and hope that they don't. I should also clean out these carbs and see if it's anything obvious like clogged jets or anything.

When I first got the bike, it pulled great through the midrange, recently it started bogging pretty bad with around half throttle through the midrange. Gotta roll off and baby it to upper RPM or whack it open and hope it doesn’t bog. I already hit up the local shop with a dyno and they can’t be bothered to get back to me about tuning it. It’s a GSXR750N, same as an M everywhere outside of America. I wouldn’t be in a big hurry to fix it, but I am going on an 800 mile ride in a week and a half. I pulled the top off one of the carbs and pulled the needle, I’m guessing someone stuck a dynojet kit in it, the needles taper down super thin for the bottom third, doesn’t look like any of the factory pro or mikuni needles I’ve ever seen. I’ve got a spare set of BST38s that I have had in a box for years that I don’t know the jetting on that I could try swapping over, I’ve got a spare set of RS38s that will pretty much eliminate the entire bottom end for power, or I could order a set of RS36s. I could also just say fuck it and pull the engine and stick an unknown 1127 in it with the RS38s I have, none of which will be perfect jetting. The bike also gets shit mileage, I just changed out the gearing, it was -1 +2 and I was switching to reserve after around 120 miles of freeway riding, which is bullshit with how big these tanks are. It’s improved a little with stock gearing, but haven’t had time to do a long ride to check mileage yet. Try and fix the stock BST38s with dynojets? Swap another set of BST38s that hopefully don’t have dynojets? Buy a set of RS36s? Say fuck it and swap in an 1127 or a bandit engine with RS38s?

I’m guessing it’s an old 1100 cyclone exhaust. It just happens to clear the plastics on my 750. Hasn’t really made it run any better though.

Finally installed them tonight. Even more crap to remove to work on it now. I think I’ll get rid of all of the breathers going from the carbs to the small cleaner box later. Also, has anyone see these rubber inserts in the back of the cross member before? I can’t find them in the parts diagrams.

I thought the duplex always had the canisters connecting 1&2 and 3&4 on the header.

I’ve got RS38s on my 7/11 with a mostly stock 1127 engine and full akro system. Never really minded the heavier throttle, and you get used to riding around the lack of any real power down low, but tons of power up top.. I’ve also ran RS36 on 750s and they make the top end amazing, below 5K, well…why would you want to be there anyway?

Pulses almost like a triple, but pulls strong through the revs though. Gonna do the valves and the plugs and make sure there aren’t any leaks anywhere. I’m also not used to having full fairings on the bike and with the new exhaust, all the noises sound strange to me right now.

So I had the header off on my 750 yesterday while doing an oil change, and decided to check for the hell of it. It fits and doesn't touch the plastics. I still need to pull the belly plastics again and make sure there's no signs of melting, and I'll need to swap out the oil pan as I currently can't get the drain plug out, and it's backfiring on engine braking pretty bad, so jetting will need to be adjusted. Also the 4-2-1 sounds really weird on a 750.

I think I was told it was an 1100 years ago, but can’t remember. I’m guessing by the shape of the header that it was for a dual exhaust bike. Tempted to see if it’ll clear the plastics on a 91/92 750.

Thanks, I need to do an oil change on it later this week and I'll pull it apart while it's drained.

Yosh seemed to think it helped. If anything it’ll look really trick.

Thanks!

Checked and looks like Suzuki used the same part for at least 40 years now, any idea how to check it before I replace it?

So as I'm going to be working on the bike before restoring it to full fairings, I figure now's the time to fix my non working oil pressure light. Already swapped the bulb and the gauges/front sub harness. I'm guessing it's the switch itself, any way to test it while I have the have the oil drained from the bike? Are they the same on all the oil cooled bikes? Thanks

Yup, those were for air to the airbox, airtech still makes the upper fairing with the intakes where the mirrors would go.

I’ve got tubes!

Thanks for all the replies. Got a set in the mail coming from Canada that should be here soon. As soon as I get all the body work back on this bike, it’s back to repairing all the damage the thieves did to my 7/11 and no more talk of stock bikes.