I Need Help!!!

[Howard]

Thanks for all of the pointers and suggestions and offers of help of how to fix the old girl, it's really appreciated and what this forum is all about @tu*

Had a long chat with Grant today who is going to send me a set of coils to try, Grant has also suggested a few things to try, so will see how I get on and let you know.

Phil, you need to be a sponsor to send a PM, but I have posted my mobile number on your visitor page, let me know when you have got it and I will delete, happy for any help mate! @tu*

 

[bluebirdphil]

Got your num and will call you tomorrow

 

[masterofevil]

I did wonder also the lead whether they are on the wrong plugs so out of order (but you've had enough birds to know which ones which) or a faulty lead

WE used to test them with the plug in the lead then moved it close to the engine block

just as an out there, you haven't connected the vacuum line up to the bottom of the fuel shut off valve?

That's just what I did recently on my carb bike after dynojetting it - I mean connecting the vacuum tube to the 'wrong' pipe on the fuel tap thingy.

It seemed to gravity feed enough fuel to get an initial cough and a half start then die as if from fuel starvation because there was no vacuum. I did this 10-12 times in a row with 20 second pauses to rest the battery because I thought it was just the float bowls slowly filling up. As soon as I twigged and put the vacuum on the right way it blew into life almost staright away.

If it has never started or idled very well since you got it there is the possibility that the valve clearances have closed up - which might explain excess fuel. With the airbox off it should be fairly easy to get the cam covers off and measure the inlet valve clearances. Getting at the exhaust valve clearances looks like it might mean taking the radiator off. Might be easier to get a compression check done ?

 

[Jaws]

It ran fine to start with.. it was only an idle speed related issue at the beginning

Howard is no slouch with the spanners so what ever has happened could proly have happened to any one on here. I am only saying it does seem to be a Howard induced problem LOL !

 

[Howard]

Cheeky twat! :-0) but a combination of things that do involve my spannering a little bit h1d1ng2
So she did not idle very well, I changed:

Wax stat
Plugs (later found I was supplied the wrong plugs, this did not help)
FPR
Coils
ECU checked on 2 other Birds works fine
More plugs (the correct ones)
Throttle bodies

I have now got her running ok, she starts and revs fine. After fitting the set of used throttle bodies she started up ok, idle was very low for about 30 seconds then rose to around 1600/1700 and then settled down ok.
Next day went out started her up and again she will not idle until warm :bang::bang:
So still not right, Now when I collected her from Tom, he reckoned it was the wax unit, he also told me that the valves had recently been checked and a few shims were replaced.....so it has got me thinking what the post above has suggested? Also thinking it may still be a sensor or loose connection/ground as I have had her idling ok from cold.
One thing I have noticed is that if I start her, then turn her off before she is warm, she is difficult to re start and seems to flood.
I have just sent Tom an email asking if he can remember when the problem started? Was it after the valve check?

 

[Tommy G]

I got Howard's email last night and replied but I thought I better pop on and put some more info on, you never know it may help.

The bike would always idle low when cold and very occasionally it would cut out (ever since I owned it) and I would have to hold the throttle on (2k RPM) until it was warm but it was never an issue to me as after a minute or two it was warm enough to idle on it's own. When it was warm it ran fine and pulled like a train, I used the bike most days on my 80 mile a day commute (during the summer) with no issues at all. I always put this down to the choke as it was a wax unit not a mechanical choke, again wasn't really an issue as it always started and ran fine when warm. I serviced the bike (inc valve clearances) because I had no idea when they were last done. It may be worth checking the linkages to make sure there's no wear on them stopping the choke moving? Also may be worth seeing if you can manually pull the choke on with the tank off and start it up when it's cold to see if the revs increase/decrease with the choke linkage being pulled in and out?

Looking through a few of Howards posts I saw he's changed the exhaust so may be worth putting the standard ones back on in case they've mucked around with the fuelling?

I do want to say though (just to quell any forum blood thirst (not that I've seen any)) I didn't sell the bike because of any issues, I don't believe were any others then what I had mentioned in the for sale post. I had got married a few months before and we were trying for a baby so the sale was to make us a bit more financially stable. (We're due July ) If it wasn't for us starting a family I would be riding the BB still.

Howard, if you can get the bike down to Shrewsbury on a Sunday then I'm totally happy to spend a day in the garage with you having a check over.

Let me know how it goes manually opening and closing the choke, it would be interesting to know if this makes a difference. (I imagine you can disconnect the wax unit and pull and push the linkages?)

Tom

 

[Howard]

Tom, No issues with you or the sale of the bike whatsoever, so no worries @tu* You told me about the cold start issue when I collected the bike and we both thought it would be a simple fix of a new wax stat, which unfortunately it isn't.
I have replaced the throttle bodies and leads with a known good set, so the problem is not anything to do with that, the wax stat,injectors, throttle position sensor, map sensor, fuel pressure regulator, spark plugs, coils have all been replaced. Original exhausts back on.
So it's really down to another sensor? Dodgy connection or valves needing adjustment?

PS. Congratulations .......Your life will never be the same again!!!8rfl@

 

[Tommy G]

Firstly, thank you. I'm starting to realise it, the bikes gone, and the car as we as my social life. I have a ?250 1.5 diesel Peugeot getting me from A-B now, not fun but very cheap to run!

I know there's no hard feeling, I've just seen a few forum witch hunts in my time so it was more for anyone else. I thought I would come on here to see a great project thread on the bike, not that you've been having problems.

I really believe it's got something to do with the choke. It's controlled by coolant temperature not electronics. Might be worth checking the thermostat isn't gummed up? and the pipes from the thermostat to the wax unit aren't blocked? I was looking in the manual and it says the choke plungers need syncing so might be worth trying that. Have you actually manually pulled the choke plungers in and out to see if that affects the revs rather then relying on the wax unit?

Might be worth checking the TPS in case the ECU thinks the throttle is more open/closed then it is, I think you can check the resistance as you move it but I would have thought it would have thrown a code up. I doubt it'll affect the starting but may be worth balancing the throttle bodies as well.

I'll carry on with my thinking cap.

I'

 

[Howard]

Thanks Tom,
It's nothing to do with the cold start wax unit, linkage or throttle bodies as they have all been replaced, the thermostat is new along with the radiator. The TPS is part of the throttle bodies that have been replaced.
The ECU has been checked on two other Blackbirds and worked fine.
I'll check the hoses going to the wax stat.
Cheers

 

[Tommy G]

When I did the shims two were slightly tight on No1 iirc, but the others were fine. I can't imagine this would cause that issue but no harm in checking them. Normally with tight valves bikes are hard to start with or without choke. When I had it, it always started fine, infact I don't think it ever failed to start once.

Have you stripped the old wax unit to see if there's anything that stands out? Looking in the manual it's serviceable, long shot to get two iffy ones. I assume you adjusted the new TBs as per manual?

May be a case of getting the old multi meter out and checking each sensor with the manual but again if it was a sensor you would think it would throw a code up.

 

[Howard]

If you think about it logically the cold start system only actually starts to work as the engine and coolant get warmer, it does nothing and does not move at initial cold start, it only starts to work as the coolant heats up and then lowers the rpm by closing air holes in the throttle bodies, as I said forget anything to do with the parts that have been changed.

It starts, it just does not idle when cold, did you change any shims?

 

[Tommy G]

I see what you're saying but this is how I understand how it works. The bike cools once the engine stops the choke plungers pull out as the wax solidifies(sp) so effectively its like pulling the choke lever on once you've turned the bike off (on an older bike) ready for when you start the bike the next time to save you pulling it on then, so the choke is actually working before you even start the bike. If the choke mechanism isn't returning then the choke isn't automatically on ready for the next ride or only partially on. I just can't understand what could cause bad idle when cold but fine when warm.

But like you say you've changed the whole unit with no avail.

I changed two shims on no1 as they were slightly tight but it didn't make it idle and higher or lower then it did before on cold.

 

[robsbird]

do a compression test on it when cold............?

me being a bit thick would say you put a thicker shim in as the engine wears the lifters.......

this would make me ask why 1 was tight as i would have thought it would have gone slacker the more miles on it

if this is the case a thinner shim was needed id have to ask why coz this would say its been wrong from day one and has it burnt the valve seat

worth a try you have tried every thing else


@tu*

 

[Tommy G]

No harm in checking, but from what I understand valves can stretch or valve seats wear/ carbon buildup on the seat which tightens clearances.

Tight valves would mean you would have to turn it over for a good amount of time to get it to fire, when I had it, it fired straight away.

Worth trying if all else has failed.

 

[Jaws]

Dunno present mileage but if less than 100,000 I am shocked it needed shims when you checked them.
The bird parts do not wear.. End of.
The reason valves tighten is that the beat theselves in to the head thereby closing the gap.
Although Honda has set the service gap at 16k that is MORE than a little conservative
To suggest the gaps will have changed from one day to the next is a bit errrrrrrr, well wrong :-0)
No mate, no idea what is going on as distance diagnosis in this case is a bit of a non-starter,, but fairly convinced it aint gonna be valves clearances !!!

 

[Howard]

As Tom said it's not a huge huge problem and the bike runs great once warm, I am now convinced it is something petty, such as a sensor or iffy connection as it has idled OK a few times.

 

[57grant]

Crikey Howard

One of the toughest problems posted!

At least its finally (mostly) sorted!
If its a poor connection, wait until spring, invest in a couple of cans of contact cleaner and painstakingly clean all the connections one by one. Dry with hairdryer and then apply a waterproof sealant after.

If its still working when the weather improves I will buy you a pint or two!

Good luck

Grant

 

[masterofevil]

Thanks for the replies so far.

She would not idle at cold from when I bought her, she also seemed to lack a bit of go and was a bit lumpy.

That's the only reason I mentioned valve clearances as a possibility - given that nearly all other possibilities had been eliminated ?

I agree entirely - valve wear and hence closure of the clearances is a slow process over thousands of miles and usually results in starting problems before anything else. If the experts on here reckon Blackbird valves are 'Rockhard' then it's unlikely to be an issue on a relatively low mileage bike.

Incidentally, I asked a local Yamaha trained mechanic about the alarming fast rate of wear on my FZR, YZF inlet valves. Perhaps unsuprisingly, he had already asked Yamaha UK the same question, the reply was 'when the minimum shim size is exceeded, grind some material off the top of the valve stem' !

 

[masterofevil]

Somebody mentioned crank/rpm sensor ? Now these can just start to go wobbly all of a sudden.
The ECU is helpless unless it knows what the rpm is at ? I did a similar exercise of changing out everything (even ECU) on an old Alfa I had and it turned out to be the crank sensor on the way out.

 

[Howard]

Air intake sensor!!!........I think? @tu*

No fault codes and I did test it with a multimeter and it seemed in spec, but yesterday whilst checking all of the harness and connections I disconnected the sensor and started her up, she idled straight away a lot better than before, I did have her running for a few minutes before this so needed to try her again from dead cold, which I have just done and she seems to idle well and seems a lot smoother to rev....so fingers crossed!
So I now need to buy a air intake sensor, had a look on David Silver and they are ?64!!!! Jesus!!
May see if I can pick a used one up on eBay.

Thanks to everyone for advice, suggestions, testing and sending me bits to try @tu* let's hope it's sorted.