• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

possible engine swap?!?!

  • Thread starter Thread starter brandonbeezy
  • Start date Start date
B

brandonbeezy

Guest
Ok sooo this is my first post on here and its a question ive been pondering. .. i have a 79 gs850g and access to a 1100g 2v engine only. .. could i install said engine in my 850 frame???
Also could someone point out how to post pictures? Lol
 
Installing the 1100 into your '79 will at least require the engine mounts from the 1100, carbs, airbox, ignition system (ignitor) and driveshaft. There will be some re-wiring necessary for the ignitor, but nothing too major.

.
 
Ok so i think i attached a picture lol. Thanks for the welcome and quick replies! If the pic is attached its a before and current of it.. the previous owner painted it like a Christmas trees then set it on fire... LOL so im going through it replacing the harness next week and last week bought a set of coils from my buddy off his gs1000
 
The major issue i was thinking about last night was drive shaft placement (side to side) but now that im more awake I think if that were an issue i could slide the motor over
 
brandonbeezy said:
Yay!!!!!!!!! !!!! I got it!!!!! Hahaha
Click to expand...
You are almost there, they are still thumbnails.

Here:

attachment.php



.
 
Steve said:
Installing the 1100 into your '79 will at least require the engine mounts from the 1100, carbs, airbox, ignition system (ignitor) and driveshaft. There will be some re-wiring necessary for the ignitor, but nothing too major.

.
Click to expand...

Might it be easier to swap the 850 chassis into the 1100 :)
 
brandonbeezy said:
The major issue i was thinking about last night was drive shaft placement (side to side) but now that im more awake I think if that were an issue i could slide the motor over
Click to expand...

Pretty sure that lines right up from what other people have said. So you don't have access to the final drive of the 1100G? too bad, lots of people will use those on their 850's or 1000's as they have a better gearing for the highways. Not by much, only drops top rev's down by 300rpm or so but it all helps. Good luck with the project, looks like you'll have to start making a 'parts needed' list.
 
Brendan W said:
Might it be easier to swap the 850 chassis into the 1100 :)
Click to expand...
Not quite sure I am following your logic, but there are too many detail differences in the frames if you try to change the bodywork. Just changing out the engine mounts and other bits mentioned is not all that hard.

By the way, the swingarm can remain the same, only the driveshaft inside it needs to be changed. The flange on the output of the secondary drive is larger on the 1000 and 1100, you need the larger flange on the proper shaft to match up to it.

.
 
Im not worried about the gearing, not gonna be on the highway very much at all. Will the bike be able to handle the extra power?? Whats the power and weight of the 1100 compared to the 850. Im basically just looking for more "easy" power and there seems to be more aftermarket available for the 1100 but also the 850 frame seems a little smaller? So could be lighter and that 850 badge would throw people way off lol
 
I know when I did My 7/11 swap on my 750, frame flex was a definite issue. Wheelied like crazy... However we are talking about 2 totally different beasts here. The 1100 16V "CHAIN DRIVE" engine was actually designed to produce more high-end street/strip performance power where as the shaft drive 8V G motors were more meant for highway, long term, low end power delivery. I think the 850 frame is more like an 1100 frame then a 750 frame so you should be set rigidity wise. The 850 has 37mm Fork tubes which is common to the big block GS's where as my 750 only had 35mm tubes. I'd say you look pretty set. I have yet to drive a shafty GS though... Maybe some other folks can put their 2 cents in... What would be a real hoot is if you put an 1100G engine in a 650G frame.... I know, I know... It won't work.
My 2 pennies.
 
Last edited:
Steve said:
Not quite sure I am following your logic, but there are too many detail differences in the frames if you try to change the bodywork. Just changing out the engine mounts and other bits mentioned is not all that hard.

By the way, the swingarm can remain the same, only the driveshaft inside it needs to be changed. The flange on the output of the secondary drive is larger on the 1000 and 1100, you need the larger flange on the proper shaft to match up to it.


.
Click to expand...

I was just wondering at what point does an 1100 engine and transmission transplant to an 850 effectively become an 850 frame and chassis transplant to the 1100.
Some folks might find the second option easier :)
 
Brendan W said:
I was just wondering at what point does an 1100 engine and transmission transplant to an 850 effectively become an 850 frame and chassis transplant to the 1100.
Some folks might find the second option easier :)
Click to expand...
The problem there is that the tank, seat, tail piece and side covers all mount to or hang from the frame. In this case, they simply don't match up.

Changing just the engine really makes more sense.

The only things complicating the matter:
- engine mounts are different, the 1100's mounts should bolt to the 850 frame.
- the carbs on the 1100 are different (larger), which requires the use of the 1100's airbox. It will hang from the same mounts in the frame.
- the 'choke' is different on the 1100. Easy enough to graft the left handlebar control housing to the 850. (I have done it.)
- his 850 has points, the 1100 has electronic ignition, hence the ignitor and its wiring.
- the output flange on the 1100 is larger, so it needs the driveshaft that matches it. The other end (at the final drive) is the same.

.
 
All the front and rear mounts are the same on the 1979 GS850G and the 1982 GS1100G. Same goes for the 3 long bolts that pass through the engine so there should be no issues with bolting the 1100G engine into the 850G frame using the existing mounts.

As for the propeller shaft, the 850G did share the same shaft as the 1100G starting in 1982. The "T" model used the older version while the "X" model used the larger version common to the 1000G and 1100G. Pryor to that, all the 850's used the smaller flange drive shaft so you will need to pick up a new/used driveshaft.

You should be able to move the signal generator over from the 850 to the 1100 engine and use as is, but I would upgrade to the electronic ignition from a 1980 or so 1000G or 850G as it would eliminate the contact points you currently have.

Hope this helps.
 
Last edited:
I did this to my GS850g years ago but with the 1000g motor, the motor went strat in using the 850 mounting plates used the 850 electrics I did end up putting some GSXR1100 carbs on it started with the GSXR1100J 34mm CV then put the GSXR1100K 36mm CV on with Harris zorst and end up with Dyna coils and Dyna S just to get the best out of it. You do (as seid) need the 1100 out put shaft as it is bigger where it bolts onto the back of the engine. You will see more power out of the 1100g from the 850g and it is like riding a differnt bike (but that is what it will be ;)) if you want the power it's worth doing, if you dont have carbs or want it to go even better the GSXR 36mm cv carbs will give you that but you will need pod fillters and have them tuned for the bike, but a starting point put 136 main jets in and that will get you going.
 
Sorry for the late reply haha Christmas has put everything on the back burner but the girls had a great one so thats all that matters.
So for the next few months I'll be sticking with the 850cc power plant and just doing cosmetic adjustments like new bars and a brat style seat. Also had a question about oil pressure, specifically how much do our engines make. Had another idea for going fast... has to do with a whistle ;)
 
Also not saying im quitting the 1100 swap just can't make it to tn for a long while
 
You must log in or register to reply here.

Similar threads

T
1980 GS450 Idles but will not rev when warm
Replies
0
Views
56
TaosBrick
T
crazyramen
Ground Loops, Mystery Fuse, and Bad Crimpers
Replies
3
Views
133
crazyramen
crazyramen
Strmstrss
1980 gs550 e
Replies
6
Views
145
Strmstrss
Strmstrss
crazyramen
Question on Points Ignition - maxxed out?
Replies
7
Views
224
crazyramen
crazyramen
R
mechanical advance limited range GS550
Replies
2
Views
90
Nessism
Nessism
Back
Top