Deep breath, Dive! (GSX400X Impulse)

[Reubix]

Hi I'm Reuben

I have no idea what I am getting myself into, but I'm doing it anyway. I have no automotive skill but I want to learn...

...So today I went and bought a 1987 Suzuki GSX400X Impulse..
... From what I have read online I'm in for the long haul, buy hey all to learn what I can.

The current state the bike is in is that it will not start (no spark) so I've done some research and found out the first thing I should do is buy a multimeter and get testing. Next is getting to the spark plugs, then it's tracing things back from there. I'll post pictures and update things as I go but from the tidbits of information I've found on this forum I've deducted that the GSX suffers from electrical issues stemming from the Coils... I have no f**king clue what a coil is but I intend to find out!

If anyone has any experience with this kind of thing and would like free booze and time way from home feel free to get in touch! Evening sessions in the garage fixing bikes and sinking brews is on me (I'm in linton BTW)

Also if the greater forum crusader has anything nice to add please feel free to share.

Current Needs 02/2014:

1987 GSX400X Impulse Manual and/or PDF file (another member has pointed me in the right direction)
New/Test battery
Sprockets, Chain
Brake rebuild kit
Engine oil/filter

Work done:
1) Bought the bike
2) Pickup the bike
3) Take pictures
4) Change ownership
5) Remove petrol tank
6) Replace/Recharge/Test Battery
7) Get a multimeter and start testing connections
8) Install new coils and test
9) Test spark plugs
10) Test all connections to the Coils
11) Test components in reverse of the coils
12) Bleed brakes, clean cylinders, check condition of pads

Work to do:

1) Attempt repair of seals on brakes, clean pistons etc.
2) Fit second coil, test spark
3) Check coolant level, top up if needed - drain if I can find the damn plug
4) Oil leak still needs looking at, find oil type (10w40 as standard) - and where the hell is the filter on this bitch? -Found it, it's a bastard to get to (behind the exhaust)

Photos:

20/02/2014:
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Wiring Diagram can be found here (not the exact same engine by the way)
http://www.graniterock.co.uk/400manuals/GSX-R400_GK76A_Wiring_Diagram.pdf

[BuzzardNZ]

You're not wrong about the electrics with the Impulse!

I had one and had the regulator/rectifier and coils go.

Apart from that it was my favourite out of all the bikes I've ever owned.

Good luck getting yours up and running :niceone:

[SMOKEU]

Apart from that it was my favourite out of all the bikes I've ever owned.


Is your SV that much of a POS that even a 1980's GSX is "better"?!

[BuzzardNZ]

Is your SV that much of a POS that even a 1980's GSX is "better"?!

No, I enjoy the SV a lot. It's just that the Impulse was my first fast bike and have such good memories of it.

[curly]

The following link maybe of some help.
http://www.dansmc.com/mc_repaircourse.htm

[bungbung]

I had an Impulse for my first bike, it was great.
Give it a good clean and look over the frame closely.
My swingarm cracked about halfway between the pivot and the axle.

[Reubix]

The following link maybe of some help.
http://www.dansmc.com/mc_repaircourse.htm

That's excellent, cheers mate!

[Akzle]

buying an 80s suzy and a multimeter... Youre a fucking masochist son.
Godspeed, brave ass crazy nigger.

[neels]

I remember riding a repulse many, many years ago. Seemed awesome at the time, but to be fair it was compared to the CB360 I owned at the time, so it's awesomeness is probably relative.

God speed, and good luck, and double what you think your budget is.

[Reubix]

Updated with photos! ...Really need a multimeter and a manual :soon:

[rustyrobot]

The following link maybe of some help.
http://www.dansmc.com/mc_repaircourse.htm

Hey, that's a great website - thanks for putting the link here. Spent the last 2 hours reading and can feel my brain expanding (and a looming drain on my bank balance... must buy project bike) :niceone:

[Reubix]

Update - 21/02/14

So I managed to do some further diagnosis today after watching this youtube video:
<iframe width="560" height="315" src="//www.youtube.com/embed/rRQ45lT2d3c" frameborder="0" allowfullscreen></iframe>

Basically I mucked around and diagnosed that there was a connection across the positive/negative of the primary coil but there was NO resistance to the secondary coil... Basically from the coil to the spark plug there was nil/nada/nothing... On both coils!

I've tested and tested and tested using the technique from the vid but still nothing... Looks like I could use two new ignition coils that will work with my bike! Anyone got any suggestions/parts to sell?

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[Akzle]

Anyone got any suggestions/parts to sell?


shitloads of each.

Nothing that will help you in this situation though.

[Reubix]

No?

That's a damn shame! I need to find out what differences there are between ignition coils from one manufacturer to the other... Having trouble tracking down that kind of info online.

[Akzle]

always wipe front to back.

[Eddieb]

Any Suzuki 400cc coil from that era should work, google whether the 750 or rgv250 ones might do also.

I found with my GSXR400F that the coils suffered from heat issues, when the bike got hot they would start to fail and once the bike sat for 10 minutes they would work fine again. If you can work out some way of keeping them cooler that should extend their life somewhat.

[Drew]

No?

That's a damn shame! I need to find out what differences there are between ignition coils from one manufacturer to the other... Having trouble tracking down that kind of info online.


Any Suzuki 400cc coil from that era should work, google whether the 750 or rgv250 ones might do also.

I found with my GSXR400F that the coils suffered from heat issues, when the bike got hot they would start to fail and once the bike sat for 10 minutes they would work fine again. If you can work out some way of keeping them cooler that should extend their life somewhat.They need to come from a four stroke twin or four cylinder. RGV is single outlet, where the multi (multi cylinder four stroke) runs a wasted spark system. One coil for no. 1 and 4 cylinder, the other for 2 and 3.

Nearly any coils from the same era will work, CBR or FZR even, it's all the same.

Have you tested for signal at the coil? The wire that goes back to the CDI (ignition box) should be earthed most of the time, and then not earthed when the rotor passes the pulse coil at the crank sensor. Usually need an oscilloscope to test that.

I've had problems with the old Suzuki multi in the past, where the magnet in the pulse generator (Hall effect sensor I think they're called) was broken and it didn't work proper.

Once you have diagnosed and sorted your spark issue, you are going to have to enjoy the fun that is the carbs (carburetors) on the Impulse. There are endless hours of fun to be had, trying to eliminate the air leaks on the airbox side of the carbs. It WILL NOT run right until you have fixed that, and I promise you WILL HAVE TO sort it as I've never seen one without buggered rubbers.

The standard battery on a lot of the earlier Suzukis, must have been an odd size they specified or something. People can only seem to get slightly taller ones, and they often mean the airbox bolts get undone to allow it to move up a bit. Dunno about the Impulse on that score, but if it's the case just shell out proper dollars for a LiPO4 battery as they are way smaller.

[Akzle]

...should be earthed most of the time, and then not earthed when the rotor passes the pulse coil at the crank sensor. Usually need an oscilloscope to test that.

can be seen on an LED test light as they have ridiculously small rise requirement.
Regular test lamp, no.

[bogan]

Update - 21/02/14

So I managed to do some further diagnosis today after watching this youtube video:
<iframe width="560" height="315" src="//www.youtube.com/embed/rRQ45lT2d3c" frameborder="0" allowfullscreen></iframe>

Basically I mucked around and diagnosed that there was a connection across the positive/negative of the primary coil but there was NO resistance to the secondary coil... Basically from the coil to the spark plug there was nil/nada/nothing... On both coils!

I've tested and tested and tested using the technique from the vid but still nothing... Looks like I could use two new ignition coils that will work with my bike! Anyone got any suggestions/parts to sell?


If you want a double check on your testing method before getting too into looking for coils (with both show bad reads it could be test method or something else) I can probably pop out this weekend.

[Akzle]

there was NO resistance to the secondary coil...


there shouldnt be? You know how coils work?

no resistance? Or infinite resistance= no continuity?

If theres no resistance, theyre fucked.

[gammaguy]

I have manuals parts and all sorts for a GK71E
You know what to do

[Reubix]

there shouldnt be? You know how coils work?

no resistance? Or infinite resistance= no continuity?

If theres no resistance, theyre fucked.

Yep, they're knackered.

Just bought 2x CB900 coils off TM :wings:

[buggerit]

Interesting to have both coils fail, makes you think doesnt it<_<

[Reubix]

Interesting to have both coils fail, makes you think doesnt it<_<

Aye, it does. A common fault with this model though... I'm thinking of putting together an extra bracket and using some heat-shrouding material to increase their longevity.

[Drew]

Aye, it does. A common fault with this model though... I'm thinking of putting together an extra bracket and using some heat-shrouding material to increase their longevity.
Coils tend to get warm of their own efforts, wrapping them could cause more problem than it's worth.

[Reubix]

Coils tend to get warm of their own efforts, wrapping them could cause more problem than it's worth.

Noted! Cheers for the tip!

Will just do the bracket/head shield idea rather than shroud the whole thing. Thanks for your input :third:

[Akzle]

cowling and ducting. Air nigger. Git' mo' air.

[F5 Dave]

Haven't bothered reading full thread 'cuz I'm lazy. Dual coils test out a bit diff from single ones. The CB ones will school you up to what's normal. As an aside people do some silly things like replace spark lead with car type silicon stuff. Also take off the plug caps & test each one separately. Should be ~5-8k each.


Typical of this model the Reg rec goes. voltage spikes to 18 or so volts which boils the battery, kills the headlight bulb, burns out the alternator (as low oil level will) and worse kills the CDI which for want of an internal regulator is a common failing on these. Aftermarket ones are available.

As Drew sez pay attn to carbs. I have one of these to dig into for an old friend. Same engine setup as a GK76 GSXR400 or something. I've put it off a few years but I promised her I'll fix it up one day. No hurry.

[RDjase]

http://www.400greybike.com/

http://www.400greybike.com/forum/viewforum.php?f=49&sid=30999136a52061a0b80d93adb37e3349

Maybe a manual in here somewhere

http://www.400greybike.com/forum/viewtopic.php?f=53&t=164

If you find one that works give me the link, I have got a Impulse for my son, its on the back burner though

[RDjase]

http://www.carlsalter.com/motorcycle-manuals.asp

[Reubix]

http://www.carlsalter.com/motorcycle-manuals.asp

Cheers for those manuals, RDjase! I'll get on to sifting through them.

Update:
So I got 2x '81 CB900 coils and tested them out using the same method... No secondary resistance still. So my testing method is shite! I highly doubt that 4/4 coils are naffed. In any case I thought I'd chuck it in the bike anyway and see how it got on... Still no spark :ar15:

What do I test next to trace back from the coils?

[F5 Dave]

Cheers for those manuals, RDjase! I'll get on to sifting through them.

Update:
So I got 2x '81 CB900 coils and tested them out using the same method... No secondary resistance still. So my testing method is shite! I highly doubt that 4/4 coils are naffed. In any case I thought I'd chuck it in the bike anyway and see how it got on... Still no spark :ar15:

What do I test next to trace back from the coils? You test HT lead to HT lead & you'll get say 18k give or take several k. or considerably less with caps removed.

The feeds will go direct to the ign box. The pulsar coils will feed to the ign box to tell it when to fire. I'd suspect it unlikely that both sides had gone at once.

[Akzle]

What do I test next to trace back from the coils?
First you need to make sure your magneto is collapsing the coils properlike...

[Akzle]

also. If you cant jewgle how to test ign coils, this job could be beyond you. Invest beer in a knowing friend.

[bogan]

Reckon I have it figured out, found this image

294394

So for dual spark coils, instead of having two secondary windings in parallel and testible as per single spark coils, there is a single winding that generates a spark across both plugs. So the resistance test is from one HT lead to the other, not back to the primary winding or to ground. Which makes perfect sense for the reading we were getting on them coils.

[F5 Dave]

Hmm, that does sound familiar, but I can't put my finger on it. . .

[bogan]

Hmm, that does sound familiar, but I can't put my finger on it. . .

Well, now you mention it; it kinda sounds like something a smart guy would say, and people would skim read instead of learning the thing, and such people now feel suitably embarrassed :whistle:

[F5 Dave]

meh I was trying to remember myself cause the memory is a bit soggy & I openly admitted I skimmed the thread a few posts back:lol:

[Reubix]

So to update!

With great thanks to Bogan he managed to track down a dodgy connection to the CDI box. On top of that we also learned how to test... Coils for a multi-cylinder engine... :brick:

Next step!
Get an inline fuel filter
Buy some HT leads for the CB900 coils
Replace stripped screws
Attempt to start the bike!

For later reference; specs of the carbs:

type - AISAN AS27VW
I.D. No. - 04A10
Bore - 27 mm
Idle r/min - 1300+/-100 r/min.
Fuel level - 9.0+/-0.5 mm
Float height - 20.5+/-1.0 mm
Main jet - #94
Main air jet - 1.2 mm
Jet needle - 5B10-3rd
Needle jet - 2.60 mm
Throtlle valve - 11.0
Pilot jet - #34
By-pass - 0.8,0.8,0.8 mm
Pilot outlet - 10.8 mm
Valve seat - 2.5 mm
Starter jet - GS1 #60, GS2 #54
Pilot screw - PRE-SET (2 turn out)
Pilot air jet - 1.35 mm
Throttle cable play - 0.5 - 1.0 mm
Choke cable play - 0.5 - 1.0 mm

[RDjase]

So to update!

With great thanks to Bogan he managed to track down a dodgy connection to the CDI box. On top of that we also learned how to test... Coils for a multi-cylinder engine... :brick:

Next step!
Get an inline fuel filter
Buy some HT leads for the CB900 coils
Replace stripped screws
Attempt to start the bike!

For later reference; specs of the carbs:

type - AISAN AS27VW
I.D. No. - 04A10
Bore - 27 mm
Idle r/min - 1300+/-100 r/min.
Fuel level - 9.0+/-0.5 mm
Float height - 20.5+/-1.0 mm
Main jet - #94
Main air jet - 1.2 mm
Jet needle - 5B10-3rd
Needle jet - 2.60 mm
Throtlle valve - 11.0
Pilot jet - #34
By-pass - 0.8,0.8,0.8 mm
Pilot outlet - 10.8 mm
Valve seat - 2.5 mm
Starter jet - GS1 #60, GS2 #54
Pilot screw - PRE-SET (2 turn out)
Pilot air jet - 1.35 mm
Throttle cable play - 0.5 - 1.0 mm
Choke cable play - 0.5 - 1.0 mm

Great find !

Should be making all the right noises soon

The carb specs are handy too, Where did you find that info? I have found two style slides in the odds and sods of carb stuff for my Impulses, have enough for a complete matching set now, shame there still a horrible carb

[F5 Dave]

Wow that was lucky, good work B. Inline fuel filter, you can get right angle ones which can be ideal to avoid kinks which block off flow and hard to trace. But filter won't stop the dreaded Suzuki silt problems from rusting tanks. Seems to pass through filters and collect in float bowls somehow. Read up threads on tank sealing if that's the issue. I've had to do every bleeding one of my Suzis bar the RF now I think of it.

[Reubix]

Wow that was lucky, good work B. Inline fuel filter, you can get right angle ones which can be ideal to avoid kinks which block off flow and hard to trace. But filter won't stop the dreaded Suzuki silt problems from rusting tanks. Seems to pass through filters and collect in float bowls somehow. Read up threads on tank sealing if that's the issue. I've had to do every bleeding one of my Suzis bar the RF now I think of it.

I'm thinking the tank has already had some kind of coating put down inside of it, ask Bogan he'd know as I showed it to him. Looked like red paint sprayed on the inside of the tank.... Definitely NOT rust and there's no rust in there!

Bought a new relay switch for the bike. Now the blinkers are..... Less on the blink

Brake bleed this weekend, got the kit and got the fluids!

Bought 2x new spark plugs to replace corroded ones

Ordered a fuel filter, just need to get more piping to fit to the fuel tank.

Went into the Suzuki shop and asked them to track down 2x HT leads for the bike. The model of coil they suggested was the exact same shape and design as the CB900 ones I picked up off an old '81 Honda (For $40 each) compared to the $150 they wanted to charge for new coils (with NO HT leads)

So we're on track!

May need to re-enlist Bogan at some point to, very clued up fulla with genuine advice and good nature. +100 Brownie points to him

[Reubix]

So the brakes aren't looking so good... After being unused for 15+ years it looks like a lot of the seals are shot and the cylinders have pitting on them. Where should I go from here? Is it possible to get the calipers off another bike and apply them without too many hassles? Do manufacturers standardize rotor size and clearance to the forks, etc. ?

I'm seeking the wise council of the greater forum on this one...

I tried to clean the cylinders but some of them refuse to come out, then others refuse to go back in. What a nightmare!

2x 4 pot calipers by the way, pretty complicated for a 150kg bike!

[bogan]

So the brakes aren't looking so good... After being unused for 15+ years it looks like a lot of the seals are shot and the cylinders have pitting on them. Where should I go from here? Is it possible to get the calipers off another bike and apply them without too many hassles? Do manufacturers standardize rotor size and clearance to the forks, etc. ?

I'm seeking the wise council of the greater forum on this one...

I tried to clean the cylinders but some of them refuse to come out, then others refuse to go back in. What a nightmare!

2x 4 pot calipers by the way, pretty complicated for a 150kg bike!

You mean the cylindrical piston has pitting, or the caliper itself?

Not standardised much at all, there might be some with the same calipers, but will likely be hard to figure out which, if any.

I've dealt with a few old calipers before (getting pistons out often requires a bit of air pressure and a well placed bit of metal), sometimes you can get away with buffing the pistons and replacing seals, other times you need to replace the pistons as well, never seen one needing a caliper replacement.

Chuck up some pics of the damage and we can probably give you a better estimate of what is required.

[F5 Dave]

Changing to non std calipers gets the WOF man hot & bothered. Air will often shift them, but be super careful to wrap a rag around & something to limit play as they come out with super force. You have to strip out the seals & clean the white powdery stuff from behind them. Usually the seals are ok (seek advice) but the dust seals get buggered.

[Drew]

I think I've got a set of those calipers here, if yours can't be serviced.

[Reubix]

I've PM'd you thanks Drew.

Will attempt to get photos up this evening if I can remember. Essentially a lot of the seals have 'jumped out' and most of the pistons refuse to budge.

...Thinking I may need an air compressor

[F5 Dave]

What you are seeing is the dust seals, not the working pressure seals.

Make drew an offer if his have moving parts, but old calipers are best kept in a system so air doesn't get in, but I'd expect Drew to have done so, unless they were cast aside. I'd still strip good ones that have been lying around as the white grunge grows by itself.

[Reubix]

I'd still strip good ones that have been lying around as the white grunge grows by itself.

What would Kurt Cobain be doing in brake calipers? :Punk:

[Drew]

What would Kurt Cobain be doing in brake calipers? :Punk:Dying...and still sucking.

[Reubix]

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Pictures of the calipers and new coils/ht leads added

[F5 Dave]

I said gunge not gru. . ., oh wait
No as you were.

[RDjase]

I think I've got a set of those calipers here, if yours can't be serviced.

Are they the ones of the parts Impulse I got off jimmy? Thought it looks fairly complete except for calipers lol

Must get back onto the Impulses

maybe a Impulse club is needed...................................

[Reubix]

Seems a dying breed, I'm just thankful I have two brothers in Japan who I can send PDF pages to for translations. Managed to track down the oil filter that way. Ha! :pinch:

[Drew]

Are they the ones of the parts Impulse I got off jimmy? Thought it looks fairly complete except for calipers lol

Must get back onto the Impulses

maybe a Impulse club is needed...................................Na, these are from one that Mikey and I were messing around with.


Seems a dying breed, I'm just thankful I have two brothers in Japan who I can send PDF pages to for translations. Managed to track down the oil filter that way. Ha! :pinch:Small internal. There are only four options for Suzuki filters I'm told.

[Reubix]

In conclusion I spent a further $1000 on the bike.... Only to find the firing order was wrong :brick:

[F5 Dave]

Ohh dear. Well those bits will be good now.

[carburator]

I have a dumb feeling that the gsx400 and gsx250( invader ) shared the same parts bin for calipers..
in that case nothing out there will fit straight in. and trying to find a caliper in good nick is hard.

[ducatilover]

In conclusion I spent a further $1000 on the bike.... Only to find the firing order was wrong :brick:

:crazy::sweatdrop Crikey