Project 3 x 2 – Old two stroke motor in a modern chassis.

Anything you like about motorbikes
User avatar
Taipan
Posts: 13965
Joined: Sat Mar 14, 2020 1:48 pm
Location: Essex Riviera!
Has thanked: 15978 times
Been thanked: 10257 times

Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by Taipan »

Not keen on the headlight unit, but love the rest of it! :thumbup:


Image

Project 3 x 2 – Old two stroke motor in a modern chassis.

About a year ago I purchased a project that my friend Roy started. Essentially he was in the process of installing a 75 Suzuki GT750 motor into a 1989 Yamaha FZR1000F chassis.

This project had some specific challenges like mounting the motor cradle to the aluminum twin spar frame. Fabricating exhausts to accommodate the new frame and also figure out a new cooling system since the old GT radiator is too bulky to fit.

To make a long story short the above issues were actually not that hard to figure out once you applied some good solid knowledge and experience to the problems. As it turns out these issues were the least of the work. The bodywork I made is all steel and my first real attempt at fabricating complex shapes out of 18 gauge flat plate steel. I ended up learning a lot and Johan from Johan’s in Clayton did a great job of hiding all the nicks and dents Ieft over from the fabrication.

The motor is ported and also came with a skimmed head to add compression, but it was prone to blowing head gaskets so I opted to go back to a stock head. So far it has behaved impeccably. I know like most people you do not care to read much and want pictures so without further ado here they are.

Image

Image

Image

Image

Image
Mr. Dazzle
Posts: 13964
Joined: Mon Mar 16, 2020 7:57 pm
Location: Milton Keynes
Has thanked: 2552 times
Been thanked: 6260 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by Mr. Dazzle »

1975->1989
1989->2023

Not sure I agree with the use of the word "modern" here.
User avatar
KungFooBob
Posts: 14223
Joined: Sat Mar 14, 2020 1:04 pm
Location: The content of this post is not AI generated.
Has thanked: 539 times
Been thanked: 7539 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by KungFooBob »

Those SV tail lights are probably only 15 years old.
User avatar
DefTrap
Posts: 4504
Joined: Tue Apr 14, 2020 8:23 am
Has thanked: 2267 times
Been thanked: 2193 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by DefTrap »

It's pretty ugly, I'd forgotten what a barge the far was. There must be a better way of showing off that engine in a modern chassis.
Bigjawa
Posts: 1931
Joined: Mon Jun 01, 2020 10:54 pm
Location: Ballymena Co. Antrim
Has thanked: 221 times
Been thanked: 878 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by Bigjawa »

Headlight looks like a nipple and at that angle will be good for blinding passing aircraft.

Don't see the point, the Exup is a bit of a barge now, losing a good 50 bhp won't help it.
David
Posts: 2134
Joined: Tue Mar 17, 2020 8:50 am
Location: Top 'o the Worle
Has thanked: 218 times
Been thanked: 689 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by David »

Mr. Dazzle wrote: Thu May 11, 2023 10:16 pm 1975->1989
1989->2023

Not sure I agree with the use of the word "modern" here.
I would have more problem with the old bit....1989 was only a couple of months ago.
Le_Fromage_Grande
Posts: 11234
Joined: Mon Mar 16, 2020 6:40 pm
Location: The road of many manky motorcycles
Has thanked: 607 times
Been thanked: 4124 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by Le_Fromage_Grande »

That isn't a 1989 FZR1000 frame, it's a 1994ish frame, the seat rails are different on later EXUPs
Also, the GT750 is not a great example of a two stroke engine, they're heavy and very mildly tuned, the 4 stroke GS750 that replaced it was faster.
Honda Owner
User avatar
Yorick
Posts: 16754
Joined: Sat Mar 14, 2020 8:20 pm
Location: Paradise
Has thanked: 10276 times
Been thanked: 6891 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by Yorick »

Le_Fromage_Grande wrote: Fri May 12, 2023 9:25 am That isn't a 1989 FZR1000 frame, it's a 1994ish frame, the seat rails are different on later EXUPs
Also, the GT750 is not a great example of a two stroke engine, they're heavy and very mildly tuned, the 4 stroke GS750 that replaced it was faster.
I had a GT750 in 1978. The GS750 was a bit faster, but not as cool and didn't sound as good ;)
Bigjawa
Posts: 1931
Joined: Mon Jun 01, 2020 10:54 pm
Location: Ballymena Co. Antrim
Has thanked: 221 times
Been thanked: 878 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by Bigjawa »

Le_Fromage_Grande wrote: Fri May 12, 2023 9:25 am That isn't a 1989 FZR1000 frame, it's a 1994ish frame, the seat rails are different on later EXUPs
Also, the GT750 is not a great example of a two stroke engine, they're heavy and very mildly tuned, the 4 stroke GS750 that replaced it was faster.
Gold forks, so its the fox eyed one that came after the RU, so 93-94 would be bang on the money.
User avatar
Skub
Posts: 12176
Joined: Mon Mar 16, 2020 5:32 pm
Location: Norn Iron
Has thanked: 9836 times
Been thanked: 10149 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by Skub »

I've a soft spot for the old water buffalo (two stroke triples,in general) and this is mostly pleasant enough to my eyes. I'm not sold on the headlamp,but it's an interesting idea at least.

I'd take a hurl on it. :thumbup:
"Be kind to past versions of yourself that didn't know what you know now."
Walt Whitman
https://soundcloud.com/skub1955
User avatar
Taipan
Posts: 13965
Joined: Sat Mar 14, 2020 1:48 pm
Location: Essex Riviera!
Has thanked: 15978 times
Been thanked: 10257 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by Taipan »

I think the headlight is just a LSL aftermarket job. It's the tray surround that spoils it.
BBB
Posts: 203
Joined: Mon Apr 19, 2021 10:56 am
Has thanked: 292 times
Been thanked: 79 times

Re: Project 3 x 2 – Old two stroke motor in a modern chassis.

Post by BBB »

Taipan wrote: Fri May 12, 2023 3:33 pm I think the headlight is just a LSL aftermarket job. It's the tray surround that spoils it.
That and the seat and tail unit.