550 overbore

[Anonymous]

hey, i remember a while back that someone posted a link with a "do it yourself" 650 kit for the GS550... anyone still have this link? i plan on picking up a spare engine, and modding it out a little, as well as a thorough rebuild, this would be my first bike engine rebuild (there are two engines i am looking at), so i would take my time doing it, building it on the slow and whatnot. upping the displacement would be a fun way to go, and i imagine a new set of pistons, coupled with a bore job wouldn't be too spendy. i imagine most of the cost would come it with new bearings, crank, trans bits... really looking to do a total job. thats why i said slow! ha ha. anyone?

[SqDancerLynn1]

Just buy a 750 You will spend a minimum 0f $1000 doing the work yourself assuming the crank does not need any work

[duaneage]

As we have poisted before on this subject it is probably not worth hopping up an old 550 unless

1. You are racing in a class limited to 550CC.
2. The bike is perfect already and all that is left to do is make it faster.
3. You cannot find a 750, 850, 100, 1100 anywhere.
4. You really have a thing for that particular bike and only it will do.

Seriously, keep the 550 like it is and grab a bigger bike. There are loads of them for sale here and on ebay. You can ship it to you for a few bills more and be happier. THe 550 has it's attributes but racebike it is not.

Don't try to make a racehorse out of a plowhorse.

[duaneage]

Buy this one

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=10961&item=6517728638&rd=1

[Anonymous]

hmmm.... odd. there are other folks who have larger than stock displacement engines on their bikes. now, did this just come from doing a top end rebuild, as any time you bore out and go to a larger piston, you'll up your displacement a little. i really love my little 550, and right now, it is all i have, and when i DO get another bike, i have a number of mods planned out for it (somewhat), like disc rear brakes, dual disc front with a hotter front end (not sure what to get yet, looking into possible parts), drop bars (drag, clubmans, or clip ons), i have a whole list done up somewhere in my bookbag. new clutch parts, all sorts of stuff. i'd almost rather keep one machine going for a few bucks at a time, than try and finance a new one (although this was a recent consideration)... rather own something outright, and have fun with it. i DON'T plan to sell my 550 as it has been a great machine...anything i can rack up 100+ miles a day on and keep ticking is a keeper to me. i just have an itch for mild custom work.

[Anonymous]

I have a 450 that the top end is messed up on. I recently bought a 500 top end to replace it with. So far so good on the install. A few more parts to buy (carbs, pods, starter), but once it running it is going in my 450 I use daily. Just doesn't do me too much good the spedo doesn't go past 85mph. I have found it cheaper to put a larger top end on than bore and all that jazz, unless you have the know how and access to that type of equipment.

[SqDancerLynn1]

What everyone is saying is that if the motor runs good don't mess with a good thing

[Anonymous]

thats why i am trying to find a spare....i can take my time and rebuild it with some slightly hotter parts, and then get as many miles as i can out of my current motor.

[AOD]

a 650 engine (chain model) is a direct fit into the 550 frame. Other than that, buy a 750 or bigger if you want some more juice. 1983's and up had 16V motors which were more potent.

~Adam

[HiSPL]

I don't know all the particulars about the swap, but I am pretty sure that the pistons, cylinders, and head from a shaft drive 650 will fit the bottom end of your 550. That would give you 100 cc more displacement and a better breathing head PLUS let you keep 6 gears and chain drive. This seems like the easiest way to hot rod your bike. You could also skim the head to raise compression some, but any thing that raises compression makes more heat also. Just be concious of that when building.....

Don't worry about the naysayers here. They mean well, but sometimes don't understand that you have to do what YOU want to do.

[first timer]

HiSPL,

thats the recipe 550 bottom, 650 sleeves, and pistons bored out 550 jugs and i can't rember either a 550 head or a 650 head, 550 head may up the compression..

i talked to a guy that had done this mod and used to race 550's back in the day. he built himself a 90 hp 550 doing these things and running some 29mm smoothies on it. it can be done but it's tons of work and extra money.

i was thinking about doing this myself but relized how much trouble it is, especially if you are a college kid, with no machine shop/garage and no full 8hr a days to work on the bike. Keep in mind these bike back in the 80's weren't very popular to modify so after market parts are very very hard to find. people mod the big bike cause there is still a aftermarket parts market. not so with the 550

in the end it was easier for me to get a gs1000 and work on that (more parts available more power out of the box)

if i was you i would get a bigger bike in bad shape and work on bringing that back to life, while you can still ride your 550 summer is coming quick. learn how to do some serious wrenching on that bike.


-ryan

[Anonymous]

the GS650 engine will bolt into the 550 frame? what years were chain drive? this would be a rather easy way to upjump the little machine. i DO want to make a hotter engine, as when i get another machine, i am gonna build the 550 into a cafe racer, so a little hotter engine would be a no-brainer. still searching for rear end pieces to make it disc brake, although i am still considering a drum rear mag as well... just having a difficult time finding a rear wheel. was it GS425/450/550L that had mags with rear drum? which would be the best to find, as i want to keep it as close to the stock size as possible to keep from upsetting the handling. i also am hoping to find a wheel that will take the stock rear sprocket, as i have this on order. any ideas?

[80gs1000e]

I've seen gsxr600 engines on ebay for around $500. That'll give you a little extra uuuummmppph. 8)

[HiSPL]

A GS750T had a rear drum on a 17" mag. I've got one but the drum lining is kinda rusty. I don't know if it's any good or not..... Can they be relined?

[Pete's GS]

I like this idea. You could either put a chain drive 650 motor in or else just buy NOS 650 slugs and rings for about $240 a set and get the liner bored for maybe $40 per hole. Get a valve job while you're at it. You'd certainly have a strong running bike and it'd be a total sleeper.

For myself, I just made my 1980 550E into a cafe racer with clip-ons and rearsets. It's lots of fun to ride now and plenty fast. The power doesn't come on till about 6K rpm but what 550 isn't like that except for the GpZ?