Hello oiler fans.
Picked up an 88 750 last week that apparently hasn't moved for 10 years. Condition is ok, worst part are headers with a lot of surface rust but they should scrub up ok. Headers look to be yosh of some sort so I'll def be putting in the effort to clean em up.
Tank insides are ok, looks like someone started to try clean it up but was hit with a wave of cbf so they stopped. Tank had a few litres of acetone in it and large flakes of rust floating in it but otherwise it looks good.
Paint scheme is interesting but a quality job.
Already began pulling it apart for a good check and clean before reassembly and see how well it runs. Yes, engine does turn, so not seized.
A 90 I owned till early last year. Stupidly sold it and wished i hadn't since...so got the 88 to amuse myself with. I think the guy i sold it to has crashed it as bits and pieces are showing up on ebay...and they are using the pics i had in the ad when i sold it lol.
Been pulling it apart most nights since I got it home. Most worrying thing was every valve had 0 clearance. Have sorted it not and they seem to be staying in tolerance.
Is the attached pic a standard needle for carbs on this bike?
No, that doesn't appear to be a stock needle. I don't know if the carbs on the Australian version of the bike differed from the US version, but the US carbs had needles that were not adjustable. Our needles were marked 5FZ91, which can be decoded to define characteristics of it's shape. The information as to which needle was fitted will be in the service manual for that bike in your market. I have a set of stock needles, should you want to return the carbs to stock. In my experience, that motor ran better on the street with stock needles.
Thanks guys, the more I open, the more I see is not OEM or standard sizing. Hoping to get at least one emulsion tube out tonight and see if it is a suzuki one. Main jet and needle are not standard.
After seeing the post about timing, I noticed my rotor is not a DENSO one. Only marking on it is 3 dots for TDC and I think it is in a slightly different position on rotor as the one on a DENSO rotor. Will take a pic tonight and upload it here.
Back in that era, at least in the US, Dynojet kits were the most common.
I don't know what was popular in Australia. Lots of people added a jet kit, an ignition advancer and sometimes a different air filter, when they added an aftermarket exhaust. Some of those things worked better than others on the street. I could get an '88 750 from 90hp to 105hp on a dyno, using those things (except the advancer, I never was a fan of those) but the lower midrange suffered quite a bit.
My suggestion would be to put the carbs back to stock, along with the air filter if a stock filter is not fitted. Check to make sure the carb slides have not been drilled; if they have, you'll want to plug the holes and re-drill them. You should be able to figure out what you have, from the markings on the jet parts and by measuring the slide holes. Mikuni jet parts are all marked with their own markings. Anything else will be some aftermarket crap. You can go up a size or two on the main jets, if the exhaust makes that necessary but you won't have to increase the main jet size as much as you would with an aftermarket air filter. You can also shim a set of stock needles, a little at a time, if it runs better that way.
Pic of rotor attached.
From what i can see on carb needle it is marked 5FZ89 and looks like it has the mikuni squares on it too...pretty hard to read tho
That actually sounds like a Mikuni needle. I remember that some markets outside the US had needles that offered some adjustment. My Canadian-spec RK was like that.
Here's what you need to do. Find a copy of a factory service manual. Figure out which model of bike you have and then look up the carbs specs for that model. You'll find a carb number stamped on the side of the carb bodies and you can use this number to make sure you have the right carbs on your bike and it will also allow you to look up every jet and needle that is used in that carb.
I would plan on rebuilding the carbs completely. Buy all of the o-rings from Suzuki, to make sure you get the right ones and measure the emulsion tubes carefully, as these wear easily. Any wear on the needles? Replace those too.
Thanks for all your help Java. Will order some bits and pieces today.
Emulsion tubes look ok, don't even really look slightly oval but are seriously dirty. Not sure what to look for with drilled slides. One hole on a couple looked kinda wonky (pic attached and kinda hard to capture in crap lighting)
If you don't have aftermarket needles and jets, you probably don't have drilled slides. Some jetting kits had you enlarge the stock holes in the slides. You'd have to compare a stock slide to yours, to see what the size should be. I haven't owned an '88 750 for years, sold my last set of the 36mm carbs a few years ago and gave my 2nd gen owners service manual to another guy, so I can't help with specifics.
I lived in Melbourne in the late 1960's... One day, I hope to make it back down there for a look around. From what I see on TV it's really changed and the OZ GP at Phillip Island has always been on my bucket list.
Phillip Island is a great track, done a few track days on my RSV and hope to do lots on this bike. We don't get the big attendance numbers at the GP or superbikes like Europe does but still has a good atmosphere. The hour and a half run to and from Melbourne used to be lots of fun years ago but the police have stamped that out. Even camping at the island now is very different to 15 years ago.
Hope you make it down one day
Goes to show if i had properly read the info already on this site i would have seen the understanding carbs sticky says that the 89-3 needle is the standard one for my bike. It also has it listed on a suzuki parts site i ordered a lot of bits from today.
Grab the 89 & 91 Yoshimura catalogues, 4 stroke performance tuning, Suzuki Slingshot 750 Hop Up manual, 88-90 Part Diagrams and 88-91 Service manual.
That should pretty much cover most of what you need.
The supertuning articles are handy too.
If you can't get hold on any of these, let me know and I might be able to get copies to you in Melbourne in a couple of weeks through my brother who's working down there in Altona North.
Got all my carb parts, new fuel lines and a few other bits in the mail today. Woooo. Pretty happy a lot of this stuff is still available from Suzuki.
Have attached a pic of the standard needle for an 88 750 in Aust.
Have a suspension question too...the J has standard rear shock on it and i would like to upgrade it, though to something closer to period correct than an S1000rr or late model gsxr shock. Are my options only ohlins or fox?
Bolted it back together on the weekend to see if it actually runs and it fired up pretty quick, hit high revs straight away so I hit kill switch. Tried again and couldn't get it running again. My guess is a fuel/air issue but I didn't have time to dig deep into the issue. Work dictates it'll be a few weeks before get a good look at it