GPz 1100 A1 Unitrack timing

[Stugill]

Good evening.

I submitted a previous post re starting issues and after I put a new starter motor in, it started but was boggy so I wonder whether I have moved the timing whilst changing the starter motor as it was a bugger to get in.

I've removed the cam cover and cam adjuster and if I turn the crank so the TDC is on the mark, then the EX and IN line type arrows don't line up 100%, they are very slightly out. There are 4 photos that relate to this.

If I do it the opposite way for comparison and line up the EX and IN line type arrows then the TDC mark is out, as per the photo that has the socket still attached to it.

The rivets of the timing chain are good, as per the manual and 44 rivets.

Any advice or insights would be gratefully received.

Cheers

Stu

[Skid Mark]

Hi Stu,
I had a similar discrepancy after reassembly of my 1000r. I was advised that minor variation is to be expected and when the top guide thightens down it may improve the alignment.
I know it’s done know but I managed to change the starter in an A2 a few weeks ago without removing the chain adjuster, also managed to keep the carbs and adjuster on the 1000r I borrowed the starter off. In the unlikely event you need to do it again, it might be worth trying to work around them. It is a bit tight getting the starter in with the oil cooler hoses but when you get it just right it will slip into place.
P

[Al]

That is perfectly ok and you wont get it any better than that. Even if it was a little further out it would not effect it in a negative way ~ it would just be 'different'.
That is not the reason it is running less than perfectly, something else is the cause of it.
Youre other post about ignition timing: I have one of those ignition rotors here spare. I put it in the vice to try to remove the nut as i was curious what i might find. Nothing would budge it and it isnt supposed to be adjustable as far as anything i have ever seen or read. Some years ago i did some work on a H1 (Z1000 MKII) injection and the timing was out. It has the same arrangement as yours; fixed for life. Myself and the owner, at his request dremelled the pickups mounting holes to move the pickups a little as there is no other satisfactory way to do it and even that seemed naughty at the time but it did work.

( ) Name witheld

[Stugill]

Cheers guys.

That is good news that the marks are ok, I'll try a few other things on the list that is in the manual to try and see what is causing it.

It's strange that on these bikes there is nothing to adjust to alter the timing.


Stu

[Al]

From the workshop manual is says that; the gap between the rotor tip and the pickup magnet should be in the range 0.4 to 0.6mm. Difficult to tell from the photo but your one (s) looks a little big perhaps. Its in the other thread. From my own limited experience, those reluctor / hall sensor 'contacts' (or whatever definition they fall into) are intolerant of any dirt or corrosion on their 'passing' surfaces and must be clinically clean..

DYNA 'S' is similar in that it needs a certain size gap to operate correctly and if its incorrect then the timing can change or fluctuate as it does if the voltage to the pickups is low and it reads either off the front or off the back of the passing magnet at will.
In both cases the manual and instructions say to move the pickups to correct the gap!
AL

[Stugill]

Cheers Al, good insight, I'll have a look at that tomorrow.

Stu

[Stugill]

Good afternoon all.

An update.

I thought it made sense to add to this thread.

It's back together and I think the timing is good, I moved the pickups and they are within the tolerances mentioned above.

It starts but won't rev past 5k and at idle it fluctuates a bit.
In addition if I operate the fast idle - choke it makes very little difference, the revs barely alter from tick over, whether it's warmed up or not.

Has anyone got any ideas?

Stu

[zed1015]

The cam chain hasn't jumped a tooth or so on the crank when you rotated it with the tensioner removed has it ?
The symptoms you have are typical of that..

[Stugill]

Zed 1015.

I thought that could be a possibility so I took the cam cover off and turned the crank till it was TDC at 1&4. The chain link rivets were as per the manual. From memory excluding the rivet right by the arrow/line which you treat as 0, it was 44 rivets to the IN line.

I can always check it again, but I counted a good few times.

Stu

[Al]

Apart from the probably 200 tests and measurements you could make, all that you have done are showing up correct so far but its still rough and wont rev beyond 5,000 RPM??

Thinking back to my only look at this stuff (EFI as it happens) quite a few conversations took place about the fuel pump etc. Mainly because it was seized but also because the owner had had the pressure regulator plated whilst it was still in one piece. Pressure regulator was scrap and i un-seized the pump and got it working. Like yours, it would not rev out and i had heard it was a common problem 'in period' as the pressure needed to operate in a narrow space of between 32 and 36 PSI or so. It was below this and that was the issue. He bought a simple glycerin filled fuel pressure gauge and i had a suitable 'T' piece. I think it was around; high twenties PSI or so.

Just a thought; there is a mistake in the old style KHI Factory EFI fuel injection manual that had people putting the fuel filter in up-side-down because thats how its shown.
The mistake is not repeated in the later DFI manual but who knows what can happen!!!

AL

[Big Fluff]

Are you "testing" this without the fuel tank connected?

With the GPz750 Turbos, the tank MUST be connected as the return line is restricted to ensure enough fuel pressure. In other words if you try to run the bike without the return line connected to the actual tank (where the valve is) then there's not enough fuel pressure for the engine to operate ove a certain RPM.

Just thought I'd throw that in the mix for you.

[Stugill]

Any advice is welcome tbh.

I've been putting the tank back on to check timing (by strobe) and general running etc. The same applies to the fuel filter which is correct etc.

Stu

[Stugill]

Good morning all.

The learned advice leads me to believe that the timing is out, I'm fairly familiar with timing but I don't want to balls it up.

Is there an idiot's guide to doing the timing?

Stu

[Al]

I'm not certain you mean this but i assume you mean ignition / spark timing.
If that is correct then i also guess you are talking about the fully or partially advanced timing.
The 'ignition advance' function is whoely contained within the IC Ignitor along with a number of other things, where 'fully retarded timing' can only be a few, at most degrees out.

If the pickups, wiring, rotor, coils and all other parts of the spark delivery paraphenalia are as they should be then the issue may be; method or IC Ignitor.
As far as method is concerned; it comes down to using a remote battery not on the bike, strobe set to zero if its programmable and orientation of the direction arrow on the inductive pickup facing the correct orientation if it is makred with a direction arrow. If thats all good and it wont achieve full advance over 4,000RPM then the IC Ignitor is suspect.

I had a thought about fuel pressure. It doesnt suggest this in the manual for safety reasons perhaps but in order to show if the fuel pressure regulator is 'letting by' at the wrong (too low) pressure; you could try to pinch the fuel return hose that runs back into the bottom of the tank whilst trying to rev it above its self imposed maximum of 5,000 RPM.

Not running above 5,000 RPM could just as easily be caused by the ignition timing not advancing correctly so maybe you are narrowing it down a bit at last.

AL

[Stugill]

Cheers Al.

I plan on having a bit of a play tomorrow.

Stu