Converting gs850 to gs1100

[Guest]

Just wondering what all is involved. Is it just just as easy as getting an 1100 block pistons and rings or does the bottom end need machined, are the piston pins the same size?

TyFerris

[850GT_Rider]

Just wondering what all is involved. Is it just just as easy as getting an 1100 block pistons and rings or does the bottom end need machined, are the piston pins the same size?

TyFerris

What year GS850? G or GL?

I believe certain GS1000 engines (and many other parts) are direct or almost direct drop-in replacements for a GS850 of similar vintage.

I think the GS1100's are a different animal.

Others in the collective will drop in soon with more detailed info, I'm sure

[Nessism]

The 850 and 1000/1100 engines are different. You can install an 1000/1100 engine in an 850 chassis though. I'm not familiar with all the particulars but believe the driveshaft must also be changed, and the carbs/airbox are also different.

[gmansyz]

The transfer case ratios are different along with the trans output shaft. I made my '82 850 into a 1000 using the 1000's crank, cylinder, pistons, head, and cams. Kept the cam chain and did not have the idler. Used the 850 clutch basket so had a smaller clutch. Used the 850 trans and transfer case gears so it was geared short. Revved really well and was a lot of fun in the city. Buzzed like 5k on the freeway at 65.
Did not even have to change the studs.
Laters
G

[TyFerris]

its an 81 gs850L

[Steve]

If you already have the 1100G engine, it is pretty much a straight swap, but you DO need to change the driveshaft, as well.

I think you need to use the front motor mounts from the 1100, but they will bolt directly to the frame, if the years are in the same range.

What year is the 850? The frames for the '80 and '81 850G and 1000G are identical. Not "nearly identical", they actually have the same part number.

The '82 and '83 850G and 1100G also share a frame, but it is slightly different than the '80/'81 frame.

Because the frames are the same, you will have an easier time of bolting a complete engine in, as long as the year is in the same range.

If one of them happens to be a "GL", don't worry about it, the "G" and "GL" engines are identical.

Gmansyz gave you some details on what fits between the 850 and 1000, I don't know if the 1100 shares the same parts.

If you are trying to simply bolt an 1100 upper end on the 850 lower end, there will be some adaptation. Besides the obviously larger cylinders, the stroke will be different (meaning a bit less than 1100cc displacement) and the wrist pin diameter will also be different, requring some modification in the rods. You would then have a lower end that was designed to handle the modest power of the 850 and will be asking it to handle a bit more power. It might handle it, I don't know.

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[bomber737]

I don't know about the 1100 but the 1000 bolts right in the frame. I just did it GL frame and G engine, the only thing I had to do was put a couple of washers on the upper rear mount on the left side. That was it. I used the 1000 shaft and rear end. The rear rims are different between the G and GL in addition to the tire size being different. GL is a 16 and G is a 17. If you put a GL rim on a G swing arm you will have to modify the axle spacer. I used 2 washers to take up the space. I have not gotten to mounting the carbs and airbox yet so well see what needs to be massaged there.

[bbjumper]

If you look up the part #'s, both the 850 and the 1100G frames are the same.

http://www.boulevardsuzuki.com/OEMpartfinder.htm#/Suzuki_Motor_of_America%2c_Inc/GS850G_%281982%29/FRAME/02880001/5602880030

[Good Times]

This is good to know. Didn't know I could swap my 850 out for an 1100.

[Steve]

If you look up the part #'s, both the 850 and the 1100G frames are the same.

Yes they are, for '82 and '83.

The 850 and 1000G frames are the same for '80 and '81.

Also keep in mind that the L frames are different than the G frames for each year group.

Not sure how much it matters, but the original poster has an '81 850L.
Not sure if the 1100 would be as easy as the 1000 for that year.

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