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Discussion Starter #1
The idle is a little rough, definitely missing a little though. Revving under no load again there is a bit of a miss once you hit 4k+. Under load, it works fine under 2k, but anything over 2k under heavy load and cylinders 2 and 3 quit firing. Confirmed by pulling plugs, 2 and 3 were fouled. Swapped 3 and 4 and ran for a little, when I pulled them 3 was now fouled and 4 was cleaned, so it must be a fuel problem I'm assuming.

I know there's the problem with the FPR going bad that makes 1 and 4 misfire, is there any known problems like that with 2 and 3?

I did sit outside under a tarp for about 6 months. Fuel was drained and fresh though. My thought is plugged injectors. I'm going to pull the airbox off tommorow and take a look down the throttle bodies to see if it's spraying ok. Also going to get new plugs, they seem ok but they should be replaced.

Other notes: airbox flapper has been removed, htev is wired to the middle position.

Any ideas or common problems I should look for before digging into this? Also reccomendations for plugs?
 

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The idle is a little rough, definitely missing a little though. Revving under no load again there is a bit of a miss once you hit 4k+. Under load, it works fine under 2k, but anything over 2k under heavy load and cylinders 2 and 3 quit firing. Confirmed by pulling plugs, 2 and 3 were fouled. Swapped 3 and 4 and ran for a little, when I pulled them 3 was now fouled and 4 was cleaned, so it must be a fuel problem I'm assuming.

I know there's the problem with the FPR going bad that makes 1 and 4 misfire, is there any known problems like that with 2 and 3?

I did sit outside under a tarp for about 6 months. Fuel was drained and fresh though. My thought is plugged injectors. I'm going to pull the airbox off tommorow and take a look down the throttle bodies to see if it's spraying ok. Also going to get new plugs, they seem ok but they should be replaced.

Other notes: airbox flapper has been removed, htev is wired to the middle position.

Any ideas or common problems I should look for before digging into this? Also reccomendations for plugs?

How much mileage is on the plugs?
Try spraying starter fluid into the intakes, if the miss settles down then you know the problem is fuel supply.
 

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Discussion Starter #3
How much mileage is on the plugs?
No idea, that's why I'm going to replace them. It hasn't been driven since I got it 6 months ago or so. I had it running, and it seemed to run better before I put it away. It needed some work I didn't have time to do, so it only ran for 15 min or so before it got shoved aside.

Try spraying starter fluid into the intakes, if the miss settles down then you know the problem is fuel supply.
Good idea, I'll give that a go too and see what happens. Thanks!
 

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Discussion Starter #4
So, last night I pulled the injectors out just because. Took a look at them, decided I didn't want to screw with them just yet. While I was there, swapped 1 for 2 and 3 for 4. Also put new plugs in (NGK CR9EHIX-9). Same deal. Also swapped some coils around, same still.

So that seems to me to rule out injectors, plugs and coils. What else could it be?!

So, 2 things if anyone knows

1) Is there any way to put a gauge on these things to check the fuel pressure? I've seen cars do some funny things with low fuel pressure, nothing like this really though.

2) The charging system isn't hooked up. The battery is fully charged though. I can't see why it would make a difference though, seems like it would run or not run with not enough juice.

Thoughts?
 

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1. Since ur plugs r getting fouled up, it seems more of an electrical issue than a fuel issue. There's no combustion hence y ur plugs keep getting fouled up so that indicates fuel is getting to th chambers at least.

2. Since ur charging system isn't hooked up, ur regulator isn't getting power either which may cause it to miss fire. I kno cuz it happened to one of mine. I ran th bike without a rectifier and noticed a significance in backfire. Once i replaced it it went away.

3. From what I understand, if th fpr went bad then th bike would constantly b flooding.
 

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2. Since ur charging system isn't hooked up, ur regulator isn't getting power either which may cause it to miss fire. I kno cuz it happened to one of mine. I ran th bike without a rectifier and noticed a significance in backfire. Once i replaced it it went away.

I race my 929 with no charging system at all. It pulls hard until the battery voltage drops below around 11V, then the electrics cut out and it stops. As long as the battery is charged it doesn't need the regulator.
 

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I race my 929 with no charging system at all. It pulls hard until the battery voltage drops below around 11V, then the electrics cut out and it stops. As long as the battery is charged it doesn't need the regulator.
Experience only suggests. Definitely electrical tho.
 

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Discussion Starter #9
1. Since ur plugs r getting fouled up, it seems more of an electrical issue than a fuel issue. There's no combustion hence y ur plugs keep getting fouled up so that indicates fuel is getting to th chambers at least.

2. Since ur charging system isn't hooked up, ur regulator isn't getting power either which may cause it to miss fire. I kno cuz it happened to one of mine. I ran th bike without a rectifier and noticed a significance in backfire. Once i replaced it it went away.

3. From what I understand, if th fpr went bad then th bike would constantly b flooding.
1. That's pretty much the conclusion I've come to. My orgininal though was that the injectors could be partially clogged, allowing too low a flow for on power, or stuck slightly open causing rich (although that doesn't make sense on hard acceleration). But swapping the injectors and getting the same result pretty much nullified that.

2. Thanks bladeracer, that's what I needed to know! Obviously I'm going to have to hook up the charging system eventually, but it's nice to know that's not the problem right now. It didn't come with a reg/rect (assuming it was broken), so I need to test the stator and get one of those.

3. I wish it was that, it would make my life easy lol. But it's only connected to 1 and 4...

I have all day tommorow to piss around with it, here's what I'm thinking right now:

Since 2 and 3 are on the same degree on the crank, it must be something that's connecting them together, electrical or mechanical. 2 things that connect them mechanically, there's the exhaust (htev specifically) that if it was in the wrong position would block flow. Checked and it's not. There's a vacuum line between the 2 and 3 throttle bodies, and of course, spark.

Starting with the obvious (but more to the point, easy :smilebig: ), airleak. I haven't checked beyond visually, but because it's simple, and I'm lazy, I'm going to start there first. It appears that the low temp high idle unit opens up an air passage to the throttle bodies. Will make sure that isn't stuck as well. Although thinking about it these would cause lean condition, and the plug looks more on the rich side of things.

Aaaand we're back to electrical. That sucks. SO, what I was thinking today, was possibly the ignition pulse generator. I don't know how it works, because I haven't looked at it yet, but my thinking is it may have a pickup that determines TDC for 1&4 and one for 2&3 and the cam sensor determines whether it's 1 or 4, or 2 or 3. Anyone know if I'm somewhere on the right track?

Also, is the timing adjustable?
 

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If I was you:

Check the free things like the air leak, mouse nest in the velocity stack, spark on all the plugs, plug gaps, try rotating the plugs to different cylinders for the heck of it.

Check the stator yet? or try running the bike on a full battery to rule out the charging system? Getting a R/R should be high on the priority list.


But to answer your question, the timing is not adjustable unless you have a powercommander with the additional ignition module too OR people buy a fixed ignition advancer (little star rotor on the right).


Good link on ignition advancing:
http://www.fireblades.org/forums/honda-fireblade/12416-factory-pro-ignition-advancer.html
 
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