I've got an 85 K100 I know the seats were a one year deal question is can I change the fiberglass tail section to a say 89 year and run an 89 year seat I really like the Corbin Gunfighter seat but they don't make them to fit 85's other than the tail section does the seat mount the same thanks

I don't think it is as simple as that, all the body work is different, the tank,seat,tail section and side covers are all different between '85 and '86. The frame is also different in the area of seat hinges.

They swap. All the K-100/1 (original eight valve bikes) used the same frame. The frame changed with the 16 valve bikes, the rear subframe is a little different to space the saddlebags out to clear the Paralever and the rear mud flap attaches differently. Even still, I am building a franken bike off a K-1100LT and am back-dating the bodywork to early K-100RT pieces. It all bolts on just fine. If you have an early K with the thermistor fuel level sensor the problem mounting a later tank isn't physically attaching it to the bike. It goes on just fine. The problem is the wiring harness not being configured for the float sensor.

Themason wrote:They swap. All the K-100/1 (original eight valve bikes) used the same frame. The frame changed with the 16 valve bikes, the rear subframe is a little different to space the saddlebags out to clear the Paralever and the rear mud flap attaches differently. Even still, I am building a franken bike off a K-1100LT and am back-dating the bodywork to early K-100RT pieces. It all bolts on just fine. If you have an early K with the thermistor fuel level sensor the problem mounting a later tank isn't physically attaching it to the bike. It goes on just fine. The problem is the wiring harness not being configured for the float sensor.

I disagree. The first year K-bike had the 'passenger grab handles' as a part of the seat. Later years had those as a part of the rear-cowl bodywork. Yes, the rear frame is the same... but the back bodywork is different. That's why the 1985 K-bikes require a unique and specific seat.

Themason wrote:They swap. All the K-100/1 (original eight valve bikes) used the same frame. If you have an early K with the thermistor fuel level sensor the problem mounting a later tank isn't physically attaching it to the bike. It goes on just fine. The problem is the wiring harness not being configured for the float sensor.

No, the early tanks fitted with a single bolt at the rear, around '86 they changed to the pin and circlip mount with different frame fittings.

Paul.

[quote="BadjerJim"][quote="Themason"]They swap. All the K-100/1 (original eight valve bikes) used the same frame. The frame changed with the 16 valve bikes, the rear subframe is a little different to space the saddlebags out to clear the Paralever and the rear mud flap attaches differently. Even still, I am building a franken bike off a K-1100LT and am back-dating the bodywork to early K-100RT pieces. It all bolts on just fine. If you have an early K with the thermistor fuel level sensor the problem mounting a later tank isn't physically attaching it to the bike. It goes on just fine. The problem is the wiring harness not being configured for the float sensor.[/quote]

I disagree. The first year K-bike had the 'passenger grab handles' as a part of the seat. Later years had those as a part of the rear-cowl bodywork. Yes, the rear frame is the same... but the back bodywork is different. That's why the 1985 K-bikes require a unique and specific seat.[/quote]

I thought we were talking about the bodywork? No the seats and seat bases are different from the '85 and '86 model years, but you can swap the body work and fit the later seat to the older bike.

I know the 85 seat has the built in hand grabs and the hand grabs on the 89 is in the rear cowling but I want to change to an 89 tail piece and 89 seat will they bolt up to the frame and tank of an 85 bike

Plug and play (you only need upper half of the duck tail).

As Inge says yes you can, your side covers will slip straight into the new cowl or duck tail and then the corbin gunfighter seat you want will go straight on. so if you can find one the same colour as your bike, its a straight swap job from go to stop

Thanks guys thats what I needed color won't be a problem as I'm going to repaint this winter