GSX400X Impulse

[impulse]

Hey fellas just got myself a gsx400x impulse I know nothing about the bikes but I am interested in learning. Would love to go test it out but its not in the best riding condition..... It needs a new back tire, some ajustment with the clutch cable because its possibly stretched, the airbox is falling to bits and has no filter in it, the carbs are needing maintainence as well. Basically the bike will start and run, sounds terrible tho, doesn't really want to idle playing with the screw makes it die or at best idle at 4k rpm. I think the most of the problem is the carbs but I want to know if anyone else has any knowledge with crappy gsx400x's and how much it cost them to fix them.... and if its worth fixing them? any help would be appreciated cheerz

[impulse]

Just got one for real cheap, bad condition but running and goot motor,maybe a nice do it up type bike.... wondering if anyone else on here has a GSX400X or had one and could help me with it in anyway....
Just another question for anyone whose had one, how fast do they go?
cheerz

[kiwifruit]

i have had a couple of these in the past, good bikes apart from the electrical fault (engine would cut out at near redline in top).
they will do about 200kmh flatout


any pics??

[impulse]

No pics yet unfortunately, its a camera shy bike.... but once its cleaned up a bit i'll get some pictures for it, probibly one of the more interesting looking bikes comming out of the 80's im hoping to restore it to look like the silver version with front farings

[kiwifruit]

cool

welcome to the site :)

[RC1]

the good old repulse i had a minter one of these,they go really well ,pretty reliable i never had any problems with mine, be good to see the pictures when finished ,

[Bonez]

A mate had one. Fantastic bike. My uncle has one corroding away in his garage.

[robertydog]

I brought one brand new many years ago. Great little bike. Even raced it at Wanganui in 1987. A real screamer.

[hellnback]

Got one of those engines in the wife's GSXR-250. Goes bloody well!
Can you tell me what it red-lines at, as our one still has the 250 tacho.

[nudemetalz]

They redline at 13,000rpm with a limiter at 13,500-14,000rpm.

[Bonez]

Hey fellas just got myself a gsx400x impulse I know nothing about the bikes but I am interested in learning. Would love to go test it out but its not in the best riding condition..... It needs a new back tire, some ajustment with the clutch cable because its possibly stretched, the airbox is falling to bits and has no filter in it, the carbs are needing maintainence as well. Basically the bike will start and run, sounds terrible tho, doesn't really want to idle playing with the screw makes it die or at best idle at 4k rpm. I think the most of the problem is the carbs but I want to know if anyone else has any knowledge with crappy gsx400x's and how much it cost them to fix them.... and if its worth fixing them? any help would be appreciated cheerzFirst thing I'd do is completely drain the carbs and fuel tank and use fresh fuel. Let fresh fuel flow through the carbs for a while out the drain screw holes in the carb float bowls.

[imdying]

some ajustment with the clutch cable because its possibly stretchedCables never stretch. There should be two adjustments, one easy one up the top which is primarily used for taking up slack and nothing else, and an adjuster down below which possibly requires removing the front sprocket cover to access.

[impulse]

yea thanks to everyone who's helping already drained the tank and carbs and flushed it out, checked the spark plugs and gave them a polish up etc, got it to idle today but its running RICH, I also did an oil change and after i did that the bike acted differently for a while.... dont know what would have caused that, asked a mate and he said the clutch was ok anyway and it wasnt something i had to worry about..... but still the bike is very tempermental and not starting every time and having fits (sometimes it will start but wnt idle and not rev over 5k rpm) still i have big plans for the lil beast
cheerz

[geoffm]

The mighty Impulse. Damn fun bikes.
I have the manual (actually for the GSXR400) if you wantum.
CDIs are known issue - you can use GSXR350 CDIs by swapping 2 wires, or ERD make them.
Mine has no airbox at all (racebike). If you airbox is beyond hope, you can fit K&N filters to the oval carb mouth. The carbs are crab and wierd and you can't get jets for them now. Daytona used to make a jet kit. Try 115-118 mains for no airbox and needles up one notch.
Parts are getting hard to find for them now - used to be as common as dirt. If anyone has a working engine, please let me know.
Geoff

[impulse]

Thanks for that man, ok so I havnt thought about the CDI yet, maybe a possibility but I hope not.... might look into it after I take the carbs in for a check up... my mate happens to think the carbs only need a tune and a bit of a clean I'll believe him only because I dont know any better. Someone mentioned something about stock suzuki coils saying that they are crap anyway do you know anything about that?

[F5 Dave]

Cables never stretch. . .
You sir have obviously never owned a 1980s Yamaha:bye: . I bought some new brake pads for my TT500 only to find once inside they were like new. think the clutch cable had stretched too. Ahh, they don't make 'em like they used to. Thankfully.

I should have read this thread first but my last post was a bit predictable.
CDIs are fine until the Rectifier dies allowing over voltage that kills the CDI & the alternator & the battery. Put a meter over the battery & check that it isn't sticking over 15V when running & not less than say, 13 either. Meter is V.cheap at Dick Smith. Chances are if the bike runs the CDI is ok, but always check the charging cct on an old Suzi. Don't run low on oil, don't use a cheapo or shagged battery & don't use bigger headlight bulb, you have been warned.

I'd strip the carbs & blow through the jets. Never poke wire. Blowing on the fronts top holes at the airbox side will raise the slides telling you the diaphragms are ok hopefully. These are odd carbs as dual, think they are Hitachi, can't remember, but have to dive into a friends one in the next couple of months.

Without the airfilter it will run like crap. If they are foam you can make one from a unifoam kit, but suspect they are paper. Thus std Suzi part best option. K&N won't be. Coils are a bit suspect, but try other things first. Make sure no one has replaced the coil HT lead for pretty car stuff with isn't copper wire.

[imdying]

I have seen the odd cable now and then... even cables off of old cars from the 20s that have no hydraulics, only cables. I stand by my earlier comment. I have never seen a cable stretch... I have however relengthened at a guess a little over one hundred cables for people who didn't heed my advice and had me shorten them because they 'stretched'. I have however seen outers shrink (the spring like outer compresses), whatever the cable activates wear, the linkages wear, the ends slog out, etc etc. It's just mho though, take it for what it is.

[F5 Dave]

Fair call.

Well it does make more sense that the outer compresses, (perhaps the OD slowly becomes a bit bigger as it is forced together) rather than the cable strands stretch, however steel is quite springy up to a point. But the effect is the same in that the free length extends.

However I haven't seen this on any other bikes than mentioned & agree that most adjusting is compensating for some external reason.

[imdying]

I just really hate having to take money off of people twice (it's not going straight into my pocket obviously lol), and because sure as God made little green apples, they'll blame me for shortening it too far. At one stage I just got totally pissed off with people, and redesigned all the cable manufacture job sheets with a section for travel. Then I'd mark down the existing and expected travel of every single job so noone could try and pin it on me.

I did see a neat display somewhere. It was a large croncrete block hanging off of about a 0.7mm cable (pretty damn small). Ruler beside it, length never changed... the guy whos shop it was said he gave the block a swing whenever he walked past just to give it a hand 'stretching'. Apparently he's not a believer either :lol:

[Jabez]

Hi, have just brought an '87 impulse & it has two problems:

1, engine is taking ages to warm up & was actually getting colder travelling to work on the motorway! (there is no thermostat & also looks like the flow restricter (have ordered a new one) has been removed by previous owner!).

2, engine is stalling, usually at idle (maybe a symptom of bad CDI?).

[F5 Dave]

Will run badly when over cool. Obviously you have tried adjusting the idle speed up a touch? Would get the cooling sorted out first though. Can tape the rad a touch in cold weather. Are you saying there is no place for a thermostat std? unlikely, would have expected an external one on a suz, but long time since saw an impulse.

[(P)]

hi fellow impulse owners and fans.

I too own a "mighty" impulse.

Mine hasn't given me any problems at all. Great bike with plenty of go.

They're really just a gsxr without fairings.

They are not popular with some on this site, as a few guys have given me shit about my bike.

Go hard guys

[wildpudding]

I agree, awesome engines, make a gsxr250 go particularly well. Though I'm still trying to figure out why one coil won't make any spark, when the coil itself it ok. Anyone an auto electrician here? :D

Stefan

[bimotabob]

Hi

When I worked at a bike wrecker we always got calls for repulse CDI and Coils.
The motors are "bulletproof" I seen a guy at the cold kiwi try to blow one up.
He held it at redline a lot all through the day but it just wouldn't die!
Not a pretty bike for sure - there are two models one being rare.
Suzuki sold many new here though they were JDM models.
a lot of 80's bikes suffer from Regulator trouble and Suzuki GSXR's give coil trouble so always check.
Boiling batterys are just the start...

Regards
BB

[bimotabob]

Hey stefan,

There may not be any actual tell tale sign of what is faulty unless you know it was overchaging etc - a manuel will and test gear will be the go.
Then you can get the ohms checked against original specs for the coil and the CDI for a start - better still try to borrow the parts from others then you can be 100% sure.
Bikes with 12v igniters will not tolerate high voltage from bad rectifiers.
NC30 hondas were a nightmare if you didn't catch them in time.
Even bike shops struggle with ignition problems - be wary of them.
Most wreckers will not take electrical parts back nor will Suzuki either.

Cheers
BB

[Jabez]

Will run badly when over cool. Obviously you have tried adjusting the idle speed up a touch? Would get the cooling sorted out first though. Can tape the rad a touch in cold weather. Are you saying there is no place for a thermostat std? unlikely, would have expected an external one on a suz, but long time since saw an impulse.

Yip, no thermostat. Went into Coleman's to order one & they showed me the microfiche diagram. One of the workshop guys also confirmed that it doesn't (I can't believe it either! ), it just has a washer type disc that must reduce the water flow! Hopefully, I will get this part tomorrow.
Have the idle set at 1500rpm, so will idle well. It just to plays up for the first few K's in middle of day, then will run fine when warm. But not in the morning, when temp doesn't get above 1/3.
Yes, I have considered taping up 1/3 or so(?) of the radiator, but only have bright yellow gaffa tape!

[barno]

I have a gorgeous Impulse. I find it hard to believe that anyone could not love such a fantastic machine that goes like a cut cat.