GS850GZ top end questions. need to know my options

[LW_Icarus]

title said it all really. the little bit of info available for this bike is here : http://www.thegsresources.com/_forum...=329938#329938

I am now faced with repairing this bike in the most cost efficient manner possible. I am fairly certain the bottom is good. at worst it may need a clutch sometime in the next year or so.

bang for the buck, whats my best option? I like a mild overbore/higher compression pistons. or swap in a 1000 top end. what are the benefits and draw backs? or in your honest opinion should I let this one die?

if I repair it lets me spread the financial burden a little easier than buying another bike, but I havent seen any ebay items that looked good, and I havent been to the local yards but I don't just want more junk that needs work.

I would love a "kit" with all the parts I need, so I could just swap em out and go. but Im sure thats outta the question.

[Anonymous]

Did you squirt a little oil in the cylinders and re-reun the compression test to see if the rings are bad or the valves - or both?

[LW_Icarus]

no. I did not. but I am leaning towards rings being fried. or both. the short version is, it got ran with the #3 intake boot fried. my guess is it went first. beyond the point that I have to disassemble the engine I didn't have motivation to continue testing.

I will try to test with oil tomorrow if I have the time.

[Anonymous]

Like swammy says, give it a wet and dry. Also check your valve adjustment to make sure that you dont have a tight valve reducing the compression. Look for the simple things first, its much cheaper.

[LW_Icarus]

will recheck with oil tonite, but just calling around I have found gs1000 and gs1100 engines for between 200 and 600 bucks, depending on what I take, electrics or not, mileage etc.

I think this is my best way out at this point. stuff the biggest, lowest mileage engine in there I can lay my hands on. I dont hold out hope that its a simple or cheap fix, it looks as if it was run very lean when the boots seperated. the only boot not seperated was the number 2, that is of course the one with the vacuum tap for the petcock, if it wouldve gone first it woulda stopped em from riding it

[LW_Icarus]

Did the oil test. it improved the 10 revolution test, but really not much difference in the crank till it stops rising test.

I have to decided to try to find as close to a drop in replacement as I can, preferably complete and ready to run. the local yard has about 25 big bore GS engines to choose from, maybe Ill get lucky and find a garage kept low mileage bike with recent crash damage.

the guy said an 1100 two valve engine was a direct swap in? I was gonna get the 1000 engine, but if the 1100 is nice and a bolt in Id go for that too I think.

of course the 850 side covers gotta stay on the bike

what are the carb differences? are the 1000 and 1100 carbs bigger diameter or just jetted different? and if I retain the stock airbox and pipe would it still be better to inrease the jet sizes one notch? I know they were lean to begin with, and fuel has changed since then.

thanks for all your input.

[SqDancerLynn1]

An 1100G should fit! Just make sure to get a shaft drive motor They are all 2 valve Make sure to get the drive shaft (850 will not fit) & maybe the motor mounts

[LW_Icarus]

I played with it some last night again. after a warm up I had #1 and #3 cylinders at 70-80 psi, well below the service limit.

I am running it in a closed room, and can hear some lower end noise I think as well. maybe just normal noise, or transmitted piston slap, but it scares me.

I am going to scrape the cash up and go get the lowest mileage engine they have to fit my bike. if the 1100 is in good shape then thatll be the one.thanks for the heads up on the driveshaft, Id have not even thought about that. will get as much as I can of the connected parts.

they also handle new aftermarket parts, including dyna and electrex stuff.I think Ive found my favorite bike shop.Used to do business with em years ago when they were a start up, man have they grown.

from the dealer the stuff needed to re ring the 850 is about 377 bucks, including new intake boots and float chamber gaskets. I haveta assume that I would spend similar on any of the bigger engines as well.

I also noticed that the wiseco pistons for the GS750 2valve engine were 2mm oversize compared to the 850 pistons. can I get that kit and use it with a real mild overbore? probably get my cylinders close with a quick hone really.

once I get another powerplant in the bike, I will investigate the overall condition of the 850 engine, and decide whether or not I wanna rebuild it.might actually get a second spare 1000 engine from the yard and build it instead.

I really don't like new bikes. I looked at em for the last three days and none really do anything for me. a 'Wing maybe (nah) or the kawasaki concourse. or if I had a better life insurance policy a 20th ann V-Max. but otherwise they are all to "star wars" looking to suit my taste.

so keeping an old one alive is gonna have to be my solution if I wanna ride.there is no way I would go through this trouble if they still made bikes like the old GS.

[duaneage]

I really don't like new bikes. I looked at em for the last three days and none really do anything for me. a 'Wing maybe (nah) or the kawasaki concourse. or if I had a better life insurance policy a 20th ann V-Max. but otherwise they are all to "star wars" looking to suit my taste.

so keeping an old one alive is gonna have to be my solution if I wanna ride.there is no way I would go through this trouble if they still made bikes like the old GS.

I was at the dealer getting parts and a salesman ( just doing his job) quipped that " it was about time to trade in the old GS" I said sure, if he could just take all that expensive plastic off one of the road rockets so I could see what a bike looks like without it. I don't like the sitting position, high insurance costs, high prices, and look alike styling of the new bikes. No one notices a new one anymore, but I get looks and compliments from my 24 year old GS. Few ever go up to a new bike owner and say" I remember when I had one of these..."

[LW_Icarus]

My favorite one was back when I had a super clean old honda 1972?cb175. used to get all kinds of people coming up and asking if that was one of the new "retro" bikes. no sir, one of them old retro bikes.

I called a dealership near work to get some prices on the gaskets, rings etc, so I could get a feel for how much I needed to get saved for this project. I started my list with "base gasket,rings, head gasket- their parts guy started laughing, said "you've already exceeded the value of the bike". I pretty much told him if that was the attitude I could expect from them Id take my business elsewhere, 377 bucks is what my list costs at a more friendly dealer closer to home.

I sell car parts and would never say that to a customer. about the time youd tell someone their 1987 RX7 wasnt worth the money to fix it youll probably find yourself in a fight. youd definitely lose a customer.

with GSs for sale in the 12-1700 range on ebay, and knowing when mine is finished it will be nicer than the average used GS,Im thinking its easily worth fixing up.

[SqDancerLynn1]

With a new bike Just knock it off the side stand would probably cost $1000 repair with all of the plastics Crashing at 35mph can total the bike 8O