1987 Suzuki Impulse GSX 400 X GK71E Restoration

**Askor** · 15th August 2017, 21:34

I used to have a gsxr250 with a gsx400x engine in it a while ago - it was hilariously fun to 18 year old me!

**jasonu** · 22nd August 2017, 14:04

They were a lot of bike for $4000 brand new, bit of a bargain really. Lots of them were snatched up by couriers.

**malcy25** · 22nd August 2017, 17:31

Originally Posted by jasonu

They were a lot of bike for $4000 brand new, bit of a bargain really. Lots of them were snatched up by couriers.

Yeah....and guys thinking they were going to win the F3 championship out of the box, first time up....

I recall getting my new TZR250 in 87 to go proddie racing. In 1988 the AMCC introduced a clubmans class which was chock full of Impulses - many ridden by guys new to racing who still had stock tyres etc....that and a few Rg400's whih had been dumped here too in the same shipment.

We were also allowed to cross enter from 250 proddie into the clubmans class, so along with my old 125, I used to have quite a lot of racing in one day....lucky I was young!

Anyway, I digress. First clubmans practice session at the Puke club circuit (2 and a 1/2 corners!), I swear there were 3 more impulses on the deck, parked up on each corner each successive lap I did. Started as a pretty full grid too....bloody orange things everywhere upside down! I was crap even though I'd been racing 3 years at that point, but hell, there could show Japanese Kamikaze pilots a few things!

**Grumph** · 22nd August 2017, 19:26

Originally Posted by malcy25

Yeah....and guys thinking they were going to win the F3 championship out of the box, first time up....

I recall getting my new TZR250 in 87 to go proddie racing. In 1988 the AMCC introduced a clubmans class which was chock full of Impulses - many ridden by guys new to racing who still had stock tyres etc....that and a few Rg400's whih had been dumped here too in the same shipment.

We were also allowed to cross enter from 250 proddie into the clubmans class, so along with my old 125, I used to have quite a lot of racing in one day....lucky I was young!

Anyway, I digress. First clubmans practice session at the Puke club circuit (2 and a 1/2 corners!), I swear there were 3 more impulses on the deck, parked up on each corner each successive lap I did. Started as a pretty full grid too....bloody orange things everywhere upside down! I was crap even though I'd been racing 3 years at that point, but hell, there could show Japanese Kamikaze pilots a few things!

Down here, Mo Haley actually built one up for a local lad. Crashed road bike I believe. Stock tank, 'glass seat with clipons and rearsets. Basically stock but a bit noisier. The lad rode it and learned quickly, moved on and upward after a couple of seasons on it. It's disappeared now but would still be a fun bike to pull out for pre89 F3 on the short tracks.

**Mikael** · 26th August 2017, 10:02

Originally Posted by sidecar bob

Hi, I have a gk71b & a genuine Suzuki service manual for one. The engines are near enough the same. If you want to know any specifics let me know.
Warning, they are a total party on wheels, I can't ride mine without bouncing it off the limiter a few times every time.

Much thanks Sidecar Bob. I have found the carb specs so far and thats about it. Thank you.

**Mikael** · 26th August 2017, 10:05

Originally Posted by sidecar bob

Well there's some encouragement for your restoration, hope that helps.

Yes my thoughts too, gave me a chuckle tho...

**F5 Dave** · 26th August 2017, 10:08

Hey if anyone has the manwel to hand can they post up the valve clearances? Guessing they are shim under bucket just to lessen my desire to open this thing up?

**Mikael** · 26th August 2017, 10:10

Originally Posted by OddDuck

You've done restoration work on other bikes before? Just checking before offering any advice.

No sir this is my first restoration but I have some help. My brother is a panel beater and I have just started some part time work at a garage so have a couple of people that can help. Any advice would be appreciated as this is all new to me. I owned a repulse back in the day so this is purely a memory lane deal. Not so concerned about getting it perfect. I really would just like to ride one of these again.

**Mikael** · 26th August 2017, 10:18

Thanks for all the comments. The engine starts and runs on 3 cylinders, front shocks are leaking fork oil, rear shock is stuffed, regulator/rectifier needs replacing as voltage is all over the place. Breaks are shot front and rear. The only good parts are the cosmetics/fairing. I have started sanding and prepping them. I need to make sure the engine is worth saving. It is not the original engine. The previous owner threaded one of the spark plug threads so I am hoping that this is not part of the problem with the cylinder that is not working. The carbs are leaking gas so prob looking at replacing the needle valves...

**Mikael** · 26th August 2017, 10:20

Originally Posted by sidecar bob

Maybe this would be worth buying , either for parts, or the main resto bike.
http://www.trademe.co.nz/Browse/List...?id=1381591821
It probably won't go for a lot.

I saw this but missed out on it. As you guessed it went for chump change.

**Grumph** · 26th August 2017, 12:00

Originally Posted by F5 Dave

Hey if anyone has the manwel to hand can they post up the valve clearances? Guessing they are shim under bucket just to lessen my desire to open this thing up?

From my notes done back in the day, I used .004in inlet and .005in exhaust clearances. Screw and locknut adjusters on all the ones I've seen.
Just like a big GSXR of the period.

**F5 Dave** · 26th August 2017, 12:12

Thanks Greg. Cool, easy then. Not 2stroke easy, but better than the last couple of foulstrokes I've worked on.

**Blackbird** · 26th August 2017, 12:43

I don't know how relevant it is to an Impulse but I have an electronic copy of a full workshop manual for a GSX-400 which covers the 1982 FZ and 1983 FD models. It's about 40 Mb so can't post here but anybody with a genuine interest can PM me and I'll look at uploading it to a Dropbox address or similar. Got hold of it for a mate who was restoring a 400 a good few years ago. He made a lovely job of it.

**James Deuce** · 26th August 2017, 19:17

Originally Posted by Blackbird

I don't know how relevant it is to an Impulse but I have an electronic copy of a full workshop manual for a GSX-400 which covers the 1982 FZ and 1983 FD models. It's about 40 Mb so can't post here but anybody with a genuine interest can PM me and I'll look at uploading it to a Dropbox address or similar. Got hold of it for a mate who was restoring a 400 a good few years ago. He made a lovely job of it.

Good try Geoff, but not even slightly related. The Repulse is basically a naked 1984-86 GSXR400. 4 cylinder, single shock rear end, etc., etc. With bits of the Sydney Harbour Bridge painted orange and tacked on randomly.

**Blackbird** · 26th August 2017, 19:21

Originally Posted by James Deuce

Good try Geoff, but not even slightly related. The Repulse is basically a naked 1984-86 GSXR400. 4 cylinder, single shock rear end, etc., etc. With bits of the Sydney Harbour Bridge painted orange and tacked on randomly.

Yeah, I know what the Impulse looks like Jim but wondered if the motor was the same. Don't have any knowledge at all about those small Suzuki motors. Never mind