Privacy guaranteed - Your email is not shared with anyone.

86' gsxr 7/11 engine swap

Discussion in 'Mechanical & Technical' started by chezmoustash, Sep 4, 2009.

  1. I am starting to look at making my 1986 gsxr 750 into a 1100 or other engine swap. I don't know what all of my options are but the 7/11 conversion is very popular and looks like a good option. what is involved in the swap? what other modifications should/need to be made with the engine swap? how long does it all take? and whats the cost? etc. any information is appreciated.

  2. Don't know myself but you may want to PM Fastcat on this forum. She is a GSXR1100 expert - racing and mechanic - and may have answers for you.

  3. I've done a couple of earlier GS 7/11's
    Bolts right in.
  4. james1300

    james1300 Track School Dazed, I think 'Fast Kat' has also done a couple.
  5. You gotta have the header for the 1100 motor (ports are 1" farther away from the oilpan than the 750) and you should also install the 1100 electronics (750 rev-limiter is like 3,000 too high for the 1100 - people do it, but the stock crank won't live long like that).

    The only other thing is misc crap - the carburetors from the 750 may or may not work depending on whether you have aftermarket carbs or the original 31mm CV OEM carbs. There are two different versions of the 1100 - there's a 1052cc lump (stock for 87 and 88 models) and then there's the 1127cc (89-92 also GSXF-1100 and bandit is similar). The 1127 motor works just wonderful with 36mm CV's but the 1052 is happier with 34mm CV's if you still want throttle-response and torque off-idle.

    There are minor differences that you might have to work around - the clutch-actuator changes from the 750 to the 1100/1200 depending on the year, so you may want to get the master-cylinder if you get one with a hydraulic actuator - although, you *can* make any actuator work with any motor.

    Oilpans and alternators swap between years, but the starter-clutch and starter-clutch cover is different between the 1052 and the 1127/1157.

    It's probably the easiest motor-swap/frankenbike project that exists, putting an 1100 (or 1200 bandit) motor in an oil-cooled GSXR-750 frame.
  6. I think if im going to spend the money to do it, I want to do it right. I want the best balance between performance and fuel efficiency. I plan on doing some track days with it so I would probably lean more toward performance(I dont wanna get :pokeowne:left behind :mfclap: . what do ya'll think is the best engine that will fit for what I am wanting?
    Also why did they put a 6 speed in the 750 but only a 5 speed in the 1100? save weight and it with the extra torque it doesnt need it?
  7. Honestly - if your goal is the best "bang for the buck" for a track bike, you'd be better off just buying one that's already setup for that - something like a 5, 6, 7 year-old (or so) R6 or gixxer6 or ZX6 or whatever...

    The frame on your first-gen 750 was pretty flexible - so much so that if you look at the bike that Kevin Schwantz used to win Daytona (what was it, 86 or 87? I forget) anyway, all of the "serious" roadracing GSXR's of that era had basically a half-a-frame welded on to the outside of the original frame to make it not such a flexi-flyer. Good luck finding decent rubber for those 18" wheels for track-thrashing too.

    Now, having said all of that... if you can find a B-12 motor, that's probably your best bet seeing as how the newest GSXR-1100 motor that is available would be 17 years old. The B-12 is basically the same as the 1127 motor except for the pistons and cams - so if you wanted to spend $500 on a set of pistons and another $100 to get the block bored/honed and then drop another $150 or so on cams, then you could easily get 130-135 reliable hp out of that lump. ...of course, then you'd also need to upgrade the clutch (the B12 was weaker than the GSXR).

    It *is* possible to get numbers closer to the 175-180hp area out of that motor without a turbo or nitrous, but it requires a big-block (which doesn't cool very efficiently) and reliability/longevity will begin to suffer - especially on a road-course. I think it's possible to get 200hp out of one of those lumps with 86mm pistons and a +7mm stroke (over 1500cc) but that one won't live long.

    ...and yeah, the 1100 didn't need the close-ratio gearbox - the 6-speed in the 750 has very close to the same overall spread between 1st and 6th as the 5-speed has between 1st and 5th. There isn't really any weight-savings involved, but there is a strength issue - 5 cogs in the space where 6 used to fit means that each cog can be a little bit thicker and more stout to stand up to that extra torque.

    There are some other options for you too... Cosworth used to make an 883cc piston-kit for the 750, and it's also possible to mix-n-match the 748cc top-end with the 749cc bottom-end and come out with 825cc of 6-speed, 750-based insanity.

    At the end of the day though, like I said in the beginning, if your end-goal is to have a reliable track bike that doesn't cost a milion dollars to fix every time you turn around, you'd be better off just buying something newer with a stock(ish) motor.

    ...or just lockwire your 750 and run it like it is - those things made about 85-90hp with a good pipe and a decent-tune-up on them.
  8. just to peel off the subject for a bit, some lucky guy dropped his 86 1100LE off to me to ressurect it from the dead. outside of the fact that some dip shit mover dropped it for him and put a small crack in the upper cowl, it is super clean. comes with the factory dry clutch*yum*

    but yeah. what jackie said. easy enough to do but why bother. you can buy a track ready thrashed r6 for around $1500 that will spank a 86 anything. why sink $1000s into something that old when $1500 buys you a turn key ready to crash r6. and if you crash it you wont cry. just buy another or patch yours up with duct tape and saftey wire until it expirescrackup:
  9. It may be that my memory is failing (I'm told that it is the second thing to go) but I *think* I remember that the dry-clutch only came on the 750 LTD model - if you've got an 1100 with a dry-clutch, it didn't leave Japan in that configuration. ...I *think*.
  10. thanks for the information fastcat. I will probably just sell it when i can afford to get a newer, faster, better handling, more reliable bike but I wanted to feel out my options. I also wasnt very clear, I want a streetable bike too not just an r6 ready to crash.
  11. what about the front forks would the forks off of the 1100 be stronger and better then the ones off the 750 or are they the same?
  12. There aren't very many differences between the 750 and 1100 to be honest with ya (which is why it's so easy to swap the 1100 motor in the 750 frame).

    The 1100 forks used electronic anti-dive units vs. the hydraulic ones on the 750. I don't remember if the inner-tubes were larger in dia. or not, but there aren't any significant differences in technology between the two. I used to use a set of first-gen 750 forks on my dragbike; I internally-shortened them and blanked-off the anti-dive units with a plate that allowed the oil-passage to be wide-open/free-flowing all the time.

    The thing that made the original GSXR-750 so mind-blowing was how light the damn things were(are). The published dry-weight was something like 450 or 460lbs (I forget exactly) and back in the mid-to-late 80's that was incredible for a production 750cc streetbike.


    the whole point of having a separate bike for the track and for the street is so that you still have a streetbike to ride and enjoy after you thrash-and-crash the track bike and are waiting for the big, brown truck to bring new parts.

    Having said all of that, it is very easy to swap out the entire front-end on any of the Suzuki streetbikes from the 80's and 90's. Suzuki used the same steering-stem on all the GSXR's from 1986 until 1994. The 1100 stayed the same (steering-stem) until 1998 (which was the last year of production for the GSXR-1100). The 750 was the same up until the 95 model (first "SRAD") and the 600 front-end from 1992 through 1995 was the same (the 600 didn't go to the "SRAD" design until 1996. The rear wheel is also easy to swap with any of those models/years and then you've got 17" rubber on both ends.

    It is, of course, possible to swap any front end into any bike, but some swaps are easier than others. The above swaps are simply bolt-on deals as long as you get the brakes, wheel, fender, and both triple-clamps along with the fork tubes. I have a front-end out of an R1 in my dragbike (which is based on the old GS frame) and all I hadda do was put the Suzuki stem into the Yamaha triple-tree and have a machine-shop knock-out a new top-tree for me.

    There are a LOT of knowledgeable people and great ideas/mods in the "Area 51" forum over at, there's a ton of great info and people (and photos) at the website, and someone already mentioned the website. There is also a member at the max-zuk website who goes by the nickname "NC_Rick" who owns "Cogent Dynamics". Rick does lots and lots of suspension tuning/mods for racebikes and his business is a racetech distributor/installer.

    With any "project" like this, the best way to go about it is to set a budget FIRST (decide how much money you can throw at it) and THEN decide what the best "bang for the buck" mods/upgrades are. If you have the discipline to develop a plan like this and then stick to it, it will keep the bike from becoming a money-pit and never-ending project that never gets ridden.
  13. Ed Who?

    Ed Who? Banned Camp

    fastcat hit on most of it. Its a FUN project, i have done several (umm..a few years back of course when they were plentiful) but the little details all add up. I had a 1990 GSXR750 with a 1216 built engine back in the day and no one in pdx could touch it....huge fun...BUT it still was valve adjustment constantly, and all the little oil cooled gremlins.

    the dry clutch ONLY came on the ltd 750, but some have found and put on 1100's. I just last winter rebuilt Matt Maldins ex yosh GSXR750SB engine (a customer "found" it online by accident) and WOW...that thing was just sexy and had the magnesium dry clutch. I have 3 Super rare Suter dry clutch's for my ZX-7RR collection...they look cool but NOT for a street bike.

    I would if you wanna throw an 1100 engine in a 750, follow fastcat recommendations and also keep it as simple as can always add stuff, change things a nice set of FCR39mm..mmmmm tasty.

    Good luck and take your time!
  14. Hi, I know this post / thread is old but Im building a post classic superbike for the pre TT classic in the Isle of Man this May. I have a race ready 1985 750 F slabby but I could do with it being an 1100, I have got an 1100 frame and a Bandit 1200 engine complete will the 1200 bandit engine go straight into the 750 frame to save time without chopping it up because the 750 frame is already braced up etc. Im running 750 SRAD front end and Maxton rear shock with SRAD wheels 180/17 rear 39mm FCR's any advice would be greatly appreciated because I'm running out of time to be messing about on things that wont work thanks Jeff
Similar Threads Forum Date
Wondering if this gsxr600 has been stolen Motorcycle Talk Aug 23, 2017
1989 Suzuki GSXR 750, Portland Motorcycles Jul 27, 2017
Looking for a Suzuki gsxr front wheel/axle spacer Tacoma-Puyallup Jul 22, 2017
1986 Suzuki GSXR750R Limited Project Motorcycles May 8, 2017
2008 Suzuki GSXR 600 Motorcycles May 8, 2017