19th Jun 2009, 23:59

I have one and it seems to be fine for an old bike. Great step up from a Honda 125. Goes great seeing as it's over 20 years old. I raced it at a HAGD at Ruapuna and it went great. I can't seem to find the correct tire pressure for both front and rear tires, if anyone knows them then that would be very helpful.

Thank you.

28th Jul 2009, 22:57

I bought one new in 1987 and had it for about 10 years and 40000km. Only stopped at the shop because my mate wanted to have a look at it. I rode out on a new bike.

Raced it once at Ruapuna drags and clocked at 13.6s at something like 91mph. There was a drag bike there running the same 400cc motor; the guys said the only mods to the engine were to beef up the electrics and remove the air cleaner. He was pulling 12.3s.

It got a bit temperamental sometimes dropping to what seemed like 2 cylinders. The only way I found to clear it was to apply full choke and let it cough for a bit. Then once it got over that it went like a rocket.

7th Apr 2010, 16:01

I bought my GSX400X about 5 years ago and kept it just a couple of years. Seat height was excellent.

Frame was a bit lightweight, and would jump around in the corners a bit when ridden hard.

I had loads of trouble with mis-firing and hard to start. I thought this was a carburation problem, but after some advice from a classic bike enthusiast, it was suggested that I look at the ignition coils as they are sited very close to the valve covers and subject to a lot of heat. Upon inspection, I found the insulation breaking down and shorting out on the frame. Two new coils and all problems sorted! Made a massive difference.

Fitted Battlax tyres and they also made a world of difference.

Wish I never sold it about 2 years ago though!

18th May 2010, 09:28

I own a 1994 GSX400 Impulse, which I bought from a dealer very cheap, as he could not get it started or going properly, but after only a couple of hours working on the electrics, it goes well.

The main key is to get the best plugs, and make sure they are set to the right gap, as the coils don`t supply enough spark to light up the houses of parliament.

I find her very reliable and quick when let loose, and very nimble in the corners when fitted with Battlax tyres.

A little thirsty when pushed hard, but not too bad when just enjoying the scenery.

My other bike is a 1981 GS650G, and the riding styles for the two bikes are worlds apart.

I love my little red Impulse, and hope I have it for many years to come.

12th Aug 2010, 23:53

Hi, a mate has a 400x Impulse, and is having trouble with it, it has dropped 2 cylinders, 1 & 4 coils are OK. Any suggestions? Cheers.

15th Aug 2010, 03:36

Hi there, this fault is mostly by the coils! Could be solved by changing the coils to some from a Honda CBR 600, but measure the resistance of the coils; it must be the same!!

Second, check the timing switch of the ignition, situated under the left hand engine cover. You can measure without demounting: should have between 85 and 120 ohm resist peak (disconnect the cable and measure). Could also be, that the screws of the sensor are loose, and the fit is not correct.

Don't hesitate to ask for more...

Greetings from Germany!!

19th Sep 2010, 02:58

I have always wanted to own one of these, since first seeing them flying around the streets of Auckland, being ridden by motorcycle couriers. There seemed to be hundreds of them in the 80's, impulses and mc couriers.

So I bought one off trademe for $400 a while back, de-reg, was missing a few vital parts CDI, & some other parts. Eventually I bought a GSXR250 CDI (wires all the same apart from one, but will rev past the redline!) & COILS from the wreckers. Just got it revinned, cost $420, which includes new number plate WOF & reg for six months.

Really like the sound of the engine, a blast to ride, light and quick. The 87 GSX400X Impulse, looks way better than the later model Impulse (1994-onwards), and goes better.

24th Sep 2010, 05:59

I bought an Impulse in 88. It was my pride and joy for a few years until I finally transformed it into a F3 racing bike. Improved power via a Terry Fitzgerald port and polish.

Sold it about a year later, have since had a classic 82 GPZ 750, and recently a TL 1000, but what do you know, spotted an Impulse in a farmer's car shed while doing my rounds, Sept 2010. Asked him if he'd consider selling. Ended up getting that bike and another identical in bits. Now have multi parts, 2 engines, wheels, tyres etc.. For 1500 bucks... Well worth the money to have another Impulse or 2... Loving it and keeping it.. Rare as hen's teeth now.

24th Sep 2010, 15:47

Just got an 86 GSX400X, the white one with red fairing. Seems to go quite well, apart from the cooling system working WAY too well, and when cold/sometimes when warm, will not idle and then be hard to start. Haven't figured this one out yet. Any ideas?

1st Nov 2010, 14:54

Just put mine up for sale after 6 years. My endearing memory is that of a very safe bike with a very punchy motor. Just be sure to fit an aftermarket pipe so you can fully appreciate the baby Katana's sound at 14k rpm..

8th Dec 2010, 00:20

I have had my 1987 GSX400X Impulse since 1991. Had 17000 ks at purchase.

I have had a great run out of it, apart from changing to Kawasaki ignition coils, and an after market CDI unit made in Auckland. Also fitted a Zorst after market can made in Christchurch (brilliant).

I have a problem at present with the bike not starting when it is hot. Changed the coils again, but still the problem. Might be the pick sensors on the end of the crankshaft. Still tracking the fault down.