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Discussion Starter #1
My XC does not like timing advance. Adding advance had minimal effect on the power curve, all it noticeably did was cause the engine to run extremely hot and rough. Since installing cams I've been running the ATS at +3 with no further increases on the PC-V. I'm going to shortly take that advance out....for pretty much the reasons I just stated.

The questions I have is: What effect does retarding the timing into the (-) negative generally have? and What is (-) retarded timing generally used for?

thanks
 

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My XC does not like timing advance. Adding advance had minimal effect on the power curve, all it noticeably did was cause the engine to run extremely hot and rough. Since installing cams I've been running the ATS at +3 with no further increases on the PC-V. I'm going to shortly take that advance out....for pretty much the reasons I just stated.

The questions I have is: What effect does retarding the timing into the (-) negative generally have? and What is (-) retarded timing generally used for?

thanks
Will let one with better knowledge answer the retard timing answer .. Just speaking for myself Advancing +4 with VM1 Cams on my 2012 XC woke it up quite nicely, ran better under all conditions ..
 

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Discussion Starter #3
Just speaking for myself Advancing +4 with VM1 Cams on my 2012 XC woke it up quite nicely, ran better under all conditions ..
Mine has never liked advance, going to +4 puts in the engine in nuclear meltdown.... even at +3 with the close-outs in for this cooler weather I can feel excess heat on my legs(which is why I'm going to retard it a few more degrees later today)+ the bike just seems to run more smoothly without the advance.
 

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Every engine has it's optimum for the conditions it's being used for. Retarding it too far will reduce the power (think Jake Brake) and over time will damage your exhaust.

I'd suggest that if you're after specific advice on what's prime then you need to stick to asking the people who have the same model and year of bike with the same cams you have.
 

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Too much advance uses up all the fuel before it's optimal and the temperature rises in the closed cylinder head. Fuel left in the mixture so the burn is more efficient in the timing cycle will help keep it cooler.

Retarding too much can allow burning fuel to exit the cylinders too soon and as it keeps burning during the exit the situation can lead to damaged valves and burned out headers.

Check a book or the internet for some basic info and you can take it as far as you want.
 

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Discussion Starter #7
I think I'll just go back to +1
 

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Fred Procycle dyno took eleven degrees out of my Vegas when he tuned it.
First took a shitload of fuel out of it with good results, then tried adding timing and found it wasnt responding to that.
Then he tried taking timing out and with eleven degrees out of it he gained ten horsepower.
ATS is still set at plus 4
He took timing out with the PCV.
 

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@Motorbikerx 11° back and 4° forward at the best means at times you're running at minus 7° from where a lot of testing/experience has shown to be close to optimum for these bikes on average. That's huge. Not saying it's wrong but with that much of a difference I'd be suspecting the cams/chain not being properly aligned. I'm no mechanic but hey, if it runs it runs and you certainly like it.
 

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@Motorbikerx 11° back and 4° forward at the best means at times you're running at minus 7° from where a lot of testing/experience has shown to be close to optimum for these bikes on average. That's huge. Not saying it's wrong but with that much of a difference I'd be suspecting the cams/chain not being properly aligned. I'm no mechanic but hey, if it runs it runs and you certainly like it.
This was my first thought too. Something was put back a little bit wrong; a tooth or two off or something.

I can't imagine any engine needing that much retardation. On the other hand doing this is a heck of a lot easier than taking the engine apart again to find the slightly misaligned (something).
 

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If that were the case, there could be a lot of HP lost to compensate. On the other hand, are you sure the timing wheel is correct?
 

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Yeah mate Ive had a look at the ATS to verify its at plus 4
Cam timing on these things is so simple how could it be out?
 

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Maybe it's not out. The chain timing is just a logical suggestion based on how far you are away from the norm. Consider that 4° advance makes a big difference in the way our bikes perform. I would think that 4° in the other direction would make an equally noticeable difference. 7° even more so.

Just seems very strange that you could go that far if everything was as it should be.
 

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Maybe it's not out. The chain timing is just a logical suggestion based on how far you are away from the norm. Consider that 4° advance makes a big difference in the way our bikes perform. I would thing that 4° in the other direction would make an equally noticeable difference. 7° even more so.

Just seems very strange that you could go that far if everything was as it should be.
Dunno mate .
Maybe @half_crazy got some ideas?
 

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Discussion Starter #17
I ended up taking 2 degrees off the advance, now running the ATS at +1. I did a 400 mile loop yesterday and for whatever reason the engine runs better, its smoother and cooler running.
 

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I ended up taking 2 degrees off the advance, now running the ATS at +1. I did a 400 mile loop yesterday and for whatever reason the engine runs better, its smoother and cooler running.
It's getting cooler every day; are you sure it wasn't just the ambient temperature causing the engine to run cooler?
 

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Discussion Starter #19
It's getting cooler every day; are you sure it wasn't just the ambient temperature causing the engine to run cooler?
OMG!!!....I know my bike's "heat" output like I know the back of my hand. I know exactly what I'm feeling coming off the engine in any temp conditions and its definitely less with less timing advance.
 

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OMG!!!....I know my bike's "heat" output like I know the back of my hand. I know exactly what I'm feeling coming off the engine in any temp conditions and its definitely less with less timing advance.
Really! I asked a relevant and simple question anyone should be able to answer with a normal and calm response and your response is to answer like a little girl on FB? Maybe something like "yes; I accounted for the difference and it's still significant" would have sounded more adult and a lot less little (OMG!!) girl.

Alrighty then Mr. Know it all. Forget I asked such a stupid question.
 
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