WTD - Fireblade coil packs @ Blyton this Wednesday
gingerprince - 9/9/13 at 11:29 AM
Don't suppose anyone here is going to Blyton Park this Wednesday (11th) and has a spare pair of Fireblade coil packs ( or even not spare that I
can borrow for 10 minutes ). My car's running low on power, and has been for a while. Confirmed with a road dyno last week, compared with one
last year when it was going well: -
Poo Dyno
Basically I'm losing around 25% power, which explains why it was not pulling to the red line well last time at Blyton - and why it will be the
same again on Wednesday unless I can find the cause.
* My original coil packs are breaking down badly - I replaced them with stick coils, which Honda forums suggested were a good idea, but info from
here and elsewhere seems to be contrary to that. Essentially it's quite possible that spark timing is retarded due to longer dwell time by
running the coils in parallel. I'd like to rule this out by putting some known good "proper" coil packs on there, but I've been
concentrating on ruling out other things before buying coils again.
* This weekends investigations found my inlet cam to be off by 1 tooth (presumably since I did my clearances)! This is now fixed, and the engine is
running noticeable smoother, but alas still down on power.
* Just for fun, I put some bigger main jets in (currently running DJ120 following rolling road session, I drill some old spares to 130). Made no
difference either way, so concluding it's not a fuel issue.
* I had ruled out reg/rec issues by disconnecting it altogether and running on battery. Besides, all reading are good.
* Carbs are spotless, cleaned them out twice. Diaphragm etc all good.
So apart from "mystical wiring issues", I've pretty much ruled most things out. I am going to perform a compression test tonight but
apart from that the only thing I can think of is spark timing, and since it's not adjustable it might just be the coils.
Any help appreciated. As I did last time, I can "live" with less power at Blyton, because it's still possible to have fun, but the
following month I've got Oulton and it'll be acutely noticeable there!
Cheers
Simon
gingerprince - 9/9/13 at 06:33 PM
Ok got between 130 and 140 psi reading across the cylinders. Lower than the 170 it should be, but not ridiculously. My old engine read lower than
that and wasn't this down on power, so I think that's the top end ruled out.
Andy B - 9/9/13 at 07:34 PM
Had a good look at your dyno graph and I reckon you have more than one issue conspiring against you.
Individual stick coils simply aren't the way forward on a carbed blade - I don't think the early ecu will drive them properly, I do have a
pair of stock ones but can't get them to you pre Blyton. That said it is unusual for the stock coils to give problems but they do get blamed for
a lot. It's normally the screw in leads or caps that cause issues - dont use anything other than copper leads and genuine coil caps. Carbon gored
stuff simply don't work
I see that you have upped the main jets but what did you do with the needle adjustment as half a circling groove is a big adjustment and if they
weren't moved to sit deeper in the needle you will be running a rich midrange
Also what fuel pump is being used - this has a huge bearing on things and set up
If we can help at all just give us a call on 01449 736633
Regards
Andy
gingerprince - 10/9/13 at 06:26 AM
quote:
Originally posted by Andy B
Had a good look at your dyno graph and I reckon you have more than one issue conspiring against you.
Individual stick coils simply aren't the way forward on a carbed blade - I don't think the early ecu will drive them properly, I do have a
pair of stock ones but can't get them to you pre Blyton. That said it is unusual for the stock coils to give problems but they do get blamed for
a lot. It's normally the screw in leads or caps that cause issues - dont use anything other than copper leads and genuine coil caps. Carbon gored
stuff simply don't work
I see that you have upped the main jets but what did you do with the needle adjustment as half a circling groove is a big adjustment and if they
weren't moved to sit deeper in the needle you will be running a rich midrange
Also what fuel pump is being used - this has a huge bearing on things and set up
If we can help at all just give us a call on 01449 736633
Regards
Andy
Thanks Andy. Pretty sure the old coils are shot - first thing I did was buy new ht cable (copper) and ngk plug caps. If I put them on now with the
coils there is a very noticeable misfire from about 9k. I do tend to worry about the proximity of the ht leads to the exhaust manifold though and
therefore temperature. Another option may be to reroute this carb side to keep away from the heat - been fine in the past though.
For the carbs I did nothing with the clip as I was just experimenting at WOT to rule things out. From previous rolling road sessions I don't
think that would help anyway, it's always been leaner than ideal mid range because the clip is already at the top and would need to be further
up ideally. Suggestion that stage 1 kit isn't designed for such a free flowing system. Not dangerously lean, just not ideal for power.
Fuel pump is original blade. I tried to rule this out a while ago (having hot idle issues too) and had same idle issues when pump disconnected and
running on whats left in the bowls. Difficult to try that at full pelt though, not sure how quickly bowls empty at WOT but guessing fairly quick!
Could a fuel pump issue cause this problem? Guess its worth checking fuel filter too.
Simon
gingerprince - 14/9/13 at 05:02 PM
OK first up big thanks to David (Jossey) for popping into Blyton with a spare set of coils and leads. Unfortunately it had started to rain so I
couldn't give enough full pelt to test whether they'd fixed the option. David let me take the coils home though and post them back so I
could test them properly - thanks again!
So having tested today, it seems my stick coils aren't causing the issue - power delivery is exactly the same with David's coils and OEM
leads/caps. I've also managed to deduce that my coils are fine (with his leads), so the issue with my old setup still seemed to be with my HT
cable and NGK caps - not causing the power issue, but causing the obvious misfires.
I also changed the fuel filter before the track day. Pretty much most things ruled out now, except fuel pump and odd quirky stuff. I think it's
time to take it to a rolling road and hope that helps diagnose what's causing it! I'll try and get hold of some OEM wires so it's at
least running with the correct ignition setup before getting on the rollers.
