2000 Hayabusa Only Running On 3 & 4 Cylinders.

[David Offor]

I reinstalled the chain and assembled enough for a run up, no change with the running of the bike, ive re read what the book says and i followed it exactly.
the photos below show the exhaust marker and where the scribed line, ends up in relation to the groove, where it should be, if i move it a pin/tooth on the crank or rotating both cams one way (keeping the 15 pin count) it throws the crank/cam timing much further out.
It looks like half a tooth tbh or maybe im reading too much into this slight difference.
I asked in a previous message about a faulty crankshaft sensor?
Im kinda clutching at straws and the bike shops ive rung have been er 'unhelpful'.
But at least im getting plenty of experience i guess, just wanna get it running right.

Update-: Added photos (in mirror and diagram).
As good as i can get my timing, could this be stretch, with rotation of engine, could it explain why the mark has moved past the fixed timing point and could this amout of movement cause my engine to run so badly?
Removing the exhaust system is a bit of a major job, id rather eliminate timing and chain, before i get involved with that.

Update:-by using a set of vernia gauges and measuring centres of nine cam chain pins and now knowing the pitch and pin count (136 pins) of the chain, my dad has worked out that the chain has not stretched and seems to be in good condition, I've also inserted the cct and pushed through the sprung plunger hole manually extending the ratchet, to eliminate the cct, engine always rests in the same position.

 

[David Offor]

Looks like we've got to the bottom of this problem at last.
Made up an adapter and connected our compressor up, put a strong arm on the 14mm bolt to stop engine turning over, here's the results-:
Pressurised No. 4, goes upto about 60 and drops down to 0 in about 3 seconds.
Pressurised No. 3, goes upto about 60 and drops down to 0 in about 3 seconds.
So at this point I'm thinking that behaviour is normal, No. 2, connect up and pressurise, it nearly takes my arm off at the pressure is held in the combustion chamber, no pressure loss.
Connect up No. 1, same result as 3&4.

So, it looks like my problems are at least bent exhaust valves, this is also consistent with the reshiming of those 3 cylinders that I had to do when I checked the clearances and explains that noise I got when I cranked it over, after fitting the head, having the timing wrong Doh!!! Just hope I haven't damaged the head.

Head off tomorrow, will post photos.
Dave.

 

[David Offor]

Head is off.
Nothing obvious im afraid .
Found shiny signs of contact on all inlets on piston crowns but no signs of contact on the valves.
Poured fuel into cylinders to check for possible ring issue, no leakage to speak of, some bubbles on all cylinders but to be expected on a cold engine and using petrol.
Visually checked piston crowns for damage.
Visually checked head gasket, looks fine.
Visually checked head and cylinder block for cracks.
Taken valves out of No 4 and No 2 (good cylinder) and checked in lathe for run out, found very slight runout on one exhaust valve from No 4, we will check the rest of the valves.
When i originally had all the valves out, i lapped them in with valve lapping paste, i know that the cylinder bores are coated (well, thats what the shop told me) could this lapping in process damage the valves or valve seats? could my valve springs have lost their tension?

 

[David Offor]

All valves checked in the lathe, coming up with inconclusive results, considering the difference in the leak down test between No 2 (holding pressure) and 1, 3 and 4 (not holding pressure).

This is so puzzeling, ill be calling a local engineering bike garge tomorrow, see if i can get some advice or ideas.

 

[David Offor]

We have found excessive wear in the valve guides, confirmed by the motorcycle engineer, he says that the valves are not seating squarely on the valve seats because of the guide wear and that it has probably been caused by poor maintence from the original owner, it would also explain why it has been getting progressively worse.
I have sourced a complete head on eBay from a 16K miles, bike for £250, new head gasket for around £60.

Hopefully this is the answer to such an obscure problem.

 

[David Offor]

I'll start a new thread I think because this has got far too long.

Ok, update-:
I sourced another complete head of a 16000 mile bike, I stripped it, lapped in the valves, rebuilt it and fitted with .30 cometic head gasket.
Without the cams in, we carried out the same leak down test, SUCCSESS, all holding pressure.
Built up the rest for a proper test, timed up, checked and triple checked with printed off workshop manual diagram.
Moment of truth.
Still the same , running terrible and backfiring through the throttle bodies, like the video I posted, at least there was no loud metallic noises this time.
I got a spare loom/harness with the ecu, so I laid it over the bike and managed to plug is in to all the relevant connectors, tried the bike again, still the same .
So, recap-:
Wiring loom eliminated
Leaking valves and loose valve stem guides eliminated
Possible blow between cylinders eliminated

I'd like to say engine timing eliminated but my problem has all the characteristics of incorrect timing.

Really running out of ideas, hope someone can have a new idea, that could explain my problem.
Dave.

 

[EchoBase]

Wow Dave, what a journey.
I wish I had a quick suggestion but I think you've tried anything that would come to mind off hand.
I do however believe all problems can be fixed.
Do you at this point feel the problem is mechanical?

 

[Danfaster]

Have you checked the cams with a degree wheel to verify they are on time according to Suzuki specifications?

 

[K-Man]

Really running out of ideas, hope someone can have a new idea, that could explain my problem.
Dave.

My 99 does the exact same thing. Any luck solving your problem since march?

 

[K-Man]

Found your solution write up here
https://www.hayabusa.org/forum/thre...bodies-and-fouling-plugs.189238/#post-3178455

That one should be stickied

 

[David Offor]

Hi ecobase and danfaster.
I just posted this reply for Karl on another thread, I've been away again but unfortunately, similar symptoms have come back to haunt my bike lol, so I'm going to start a new thread.


I actually did get to what I thought was to the bottom of the problem.
I found that during a leak Down test, 3 of my cylinders were not holding pressure, so I took the head off, removed the valves and found that there was excessive sideways movement, between valve stem and valve guide, I concluded, that the valve was seating off centre, causing partial combustion into the throttle bodies.
I sourced a 16k head from eBay (complete with cams) rebuilt and voila, ran really well.
So I think that I got to the bottom of that problem but now, after going travelling and coming back, it's got similar symptoms again but I think my injectors are partially blocked, I'm going to open up another thread, to pick people's brains again.
Hope this helps you.
Dave.

 

[Hitman wffw]

Hi ecobase and danfaster.
I just posted this reply for Karl on another thread, I've been away again but unfortunately, similar symptoms have come back to haunt my bike lol, so I'm going to start a new thread.


I actually did get to what I thought was to the bottom of the problem.
I found that during a leak Down test, 3 of my cylinders were not holding pressure, so I took the head off, removed the valves and found that there was excessive sideways movement, between valve stem and valve guide, I concluded, that the valve was seating off centre, causing partial combustion into the throttle bodies.
I sourced a 16k head from eBay (complete with cams) rebuilt and voila, ran really well.
So I think that I got to the bottom of that problem but now, after going travelling and coming back, it's got similar symptoms again but I think my injectors are partially blocked, I'm going to open up another thread, to pick people's brains again.
Hope this helps you.
Dave.

Any update my bike is a 2000 gen1 with the ecu flash and the. Ikw is hard to start but once it gets warm it's ok the guy at the dealer told me cylinders 3&4 aren't making good power which could me checking valves .. I hope u find ur problem and I pray I find mines too

 

[David Offor]

Hi Hitman.
I did get to the bottom of my problem, it was a bad fuel pump and partially blocked injector filters.
Check out my recent thread about possible blocked injectors.
I'd tell anyone whose having starting/running problems to eliminate they're fuel pump, injectors, with a couple of easy tests, before throwing loads of money at the bike, usually it's just a simple thing, causing the worst problems, fuel pumps can act inconsistently, so can injectors and if you have a fuel problem, it will affect plugs and just throw up loads of red herrings.
Good luck.

 

[fallenarch]

FWIW, You could still beat a ZX14 with just 2 cylinders.......

 

[Hitman wffw]

Hi Hitman.
I did get to the bottom of my problem, it was a bad fuel pump and partially blocked injector filters.
Check out my recent thread about possible blocked injectors.
I'd tell anyone whose having starting/running problems to eliminate they're fuel pump, injectors, with a couple of easy tests, before throwing loads of money at the bike, usually it's just a simple thing, causing the worst problems, fuel pumps can act inconsistently, so can injectors and if you have a fuel problem, it will affect plugs and just throw up loads of red herrings.
Good luck.

I remember seeing u said u cleaned the injectors how did u come to the notion that they where partically blocked .. I cleaned mines and the clock to b spraying better then when blocked .. I also went and changed my fuel pump to a inline pump and regulator

 

[David Offor]

Hi Hitman, sorry about my Late reply.
The injectors that I had cleaned, we're for the out of tank fuel pump, set up because I converted to an in tank set up, I sold those injectors (to get some money back) because I was told that the in tank pump injectors ran at a higher pressure, so I thought I better have the corresponding injectors for that pump.

 

[David Offor]

After re reading this thread, I thought I'd update it.
I'm now going down the cam chain route (I should've taken six packs advice and eliminated it ages ago), my timing marks have never lined up properly and given my bikes 40,000miles and the state of the oil that came out of it, it might have bad wear on the links themselves that I didn't consider when measuring for stretch.
New chain is ordered, hopefully get it next Tuesday.
The pics are where my exhaust cam timing mark lines up, 1 tooth either way and the diagram shows where it should line up.
Fingers crossed that this will be the answer, at least it will rule out the timing chain.

View attachment 1570039

 

[David Offor]

An easy timing chain stretch test (which I never thought of before), there's easily 1/2 tooth of movement in between the links down the drive side (non tensioner side) of the chain, this could be my ongoing problem.