Blown Engine Come Back

[fz6bk]

I just replaced the throttle bodies and injectors, and the ignition coils, with ebay parts. The bike seems to be running strong, but it's hard to find a place to hit the rev limiter even in 2nd gear in NYC during the day. Will take it out for a real ride when possible.

The ECUnleashed work was done relatively locally presumably in coordination with the company. I should ask exactly what was done. My memory is that some ignition advance is typical.

What is an ignition trigger wheel?

 

[TownsendsFJR1300]

The trigger wheel is under the right side cover just forward of the clutch.

Part #14: https://www.partzilla.com/catalog/yamaha/motorcycle/2007/fz6-fzs6w/electrical-1

It triggers the spark (electronic points if you would) for the coils.

FI has filed the alignment notch (that mounts to the crank) in order to rotate and advance the spark from the stock, factory setting..


.

 

[fz6bk]

Gotcha. I suspect it has not been modified on either the old or new engine.

I've now had a chance to ride the bike hard after changing the throttle bodies/injectors, coils and spark plugs (again) on the "new" engine. It still hesitates at 13k in 2nd gear and above.

My plan, In order, at present:

- Double check fuel line(s) for kinking
- Pull the PC V again
- Check fuel pump filter
- Check valves
- Replace fuel pump
- Investigate while on the dyno (I'd prefer to have this sorted before bringing it in)

What am I missing?

 

[fz6bk]

I cleaned the fuel pump filter, adjusted the TPS slightly (max reading was a little low), checked the spark plugs again (they looked fine), checked the valves, leak down tested (less than 1% leakage in all four cylinders), and pulled the PC V again.

The bike rips to the redline in the higher gears now. As I think was suggested previously, the PC V was the likely culprit (for the high rpm hesitation with the new engine).

I'll get it on the dyno, maybe try to resolve the PC V and possible ECUnleashed issues, and in any case, make sure that it's not running lean.

I might open up the old engine at some point and see what actually went wrong.

I think case closed, for now. Thanks!

 

[fz6bk]

I had the bike dynoed last spring. PC V map supplied by the exhaust manu. was very rich causing the high rpm hesitation. Fixed on the dyno. Sheet attached.

I've put some miles on the bike including a track day without issue since, knock on wood.

 

[Motogiro]

Nice riding and that motor sounds so good!

 

[Gary in NJ]

Dude, GREAT video. Was that NJMSP? I wanted to see the second pass!

 

[fz6bk]

Thanks! The video is at High Plains Raceway in Colorado. I do ride/race at NJMP but on an R6. The FZ6 is a pleasure to ride on the track though. More comfortable, less power to worry about.

 

[CanadaFZ6]

Good riding, you look pretty fast out there! Just getting into track more myself.

 

[fz6bk]

Good riding, you look pretty fast out there! Just getting into track more myself.

Thanks! There's really no better place to ride if you want to go fast or get better at riding. I still have fun on the street, and it's practical when the weather is nice, but you're really rolling the dice if you push hard. I've lost the front on the street twice and was lucky not to get hurt. I've crashed 18 times in 4 seasons at the track. I did break my foot this year, but I've otherwise been okay.

The track day community is great. The race scene is even more fun once you get a couple seasons under your belt. E.g. here's a race from this year from another rider's perspective. I'm in the black/white/red coming around the outside into turn 1 and you'll see me crash in the 1st minute. I rode back to the pits. You'd never get the chance to find the limit like this on the street (without dying).

 

[Gary in NJ]

Another fun video. Was that "just" a low-side crash, or did something fail?

 

[fz6bk]

Another fun video. Was that "just" a low-side crash, or did something fail?

I added a little bit of gas while probably still adding a little lean. No good I'd usually get a small slide at that track--the grip is excellent, but for probably two reasons I got no warning: 1. first lap, maybe the tire wasn't fully up to temp 2. not weighting the pegs/rear enough because of the foot injury. It's hard to be sure, but that's my theory.

 

[Andz]

Moral of the story:

Yamaha spend millions on research and development, it works fine stock, leave it alone.

 

[fz6bk]

Moral of the story:

Yamaha spend millions on research and development, it works fine stock, leave it alone.

You're drawing this conclusion for what reason?

Before the swap, the first engine "blew", i.e. lost power in one cylinder, for unknown reasons. It could have been a failure with oem or aftermarket parts. I haven't torn it down and we may still never know.

After the swap, the cylinder 4 spark plug didn't burn up again after replacing the oem throttle bodies and ignition coils, actual cause also unknown, but either part may have also played a role in the first engine problem. The PC V map problem was secondary.

The oem fueling on the fz6 is terrible. The exhaust is heavy and restrictive. The suspension is borderline unsafe if you're going fast--undersprung and underdamped. The rearsets and the center stand scrape easily.

Is mediocre "good enough"? It depends entirely on how you're using the bike. Almost no one going actually fast on any bike has an oem exhaust/fueling or is on stock suspension, among other typical changes.

The only reasonable conclusion to draw is to install parts correctly and tune the bike when relevant. If there had been a problem with fueling with either engine, we would have seen it on the dyno before there was a bigger problem.

 

[Andz]

You're drawing this conclusion for what reason?

Based on my 16 years experience with it, the stock Fazer was fine for me and the way I ride, all I changed was the pipe.

If you want to go faster, buy a faster bike.

I sold my Fazer and bought a Tracer, again all I have changed is the pipe, it is fine for my requirements.

My comments are just my opinion.

 

[fz6bk]

Based on my 16 years experience with it, the stock Fazer was fine for me and the way I ride, all I changed was the pipe.

If you want to go faster, buy a faster bike.

I sold my Fazer and bought a Tracer, again all I have changed is the pipe, it is fine for my requirements.

My comments are just my opinion.

I was asking what specifically in this thread leads you to this conclusion? i.e. Why is "stock is good enough" the moral of this story? Not why is it the moral of your story.

And sure, the 9 and its derivatives are marginally faster in a straight line than the 6, but that's only one part of going faster. I'd say the following 3 things are more important:

1. Consistent brakes, so that you can brake progressively harder with a predictable outcome
2. Good suspension, so that you can brake, turn in, and exit a corner optimally
3. Good fueling, so that you can enter corners without interfering engine braking, and exit on the gas without disrupting the bike

The stock 9s might be worse the stock 6 in the latter 2 categories, and are certainly worse than a modified 6 in all three. I found the stock 9 I rode to have a snatchy throttle, and scary suspension/geometry. Can this be fixed? Of course. I would for sure go faster (around corners) on my current FZ6 than a stock 9. You could recreate my FZ6 for 4-5k. You could maybe get a comparable 9 for 7-8k, and that's if you want a torquey triple. I like the inline 4.

It's economical and practical to find a bike that fits your form factor, power band preference, and budget, and to fill in the gaps where the manufacture prioritized margins over performance.

 

[Gary in NJ]

My FZ6 is about as sorted as one can get. It’s predictable, well mannered and comfortable. I’m sure I’d have to spend well north of $10-12k to replace it.

 

[fz6bk]

My FZ6 is about as sorted as one can get. It’s predictable, well mannered and comfortable. I’m sure I’d have to spend well north of $10-12k to replace it.

Sounds nice! Likewise, every time I think about replacing mine, I just can't justify it. If I blow another engine or have cash to burn, maybe. But it fills the "r6 that can carry my girlfriend comfortably" niche so well (after mods).