Exact list of modifications needed to backfire and show flames. Solution unclear!HELP
MECP Certified Installer
Joined: Feb 2009
Posts: 3,176
Likes: 3
From: Mesquite, TX-DFW
Dang just thinking of the funny idle I should do a video of when it's fully warmed up. Fully warmed my engine idles at about 450-500 rpm but that is where it's happy, and the sound is freaking cool. There is actually a video on youtube of my engine idling below starter speed, lol. When you big exhaust your idle goes down but if you try and raise it to stock 750ish, you'll never get it.
What the **** happened to this place!? I came in here for a laugh and all I find is helpful, technical information 
There was a time, that someone asking to spit flames with a 15 post count would leave this place in tears and sell their car!
Boy, this place sure has mellowed....
There was a time, that someone asking to spit flames with a 15 post count would leave this place in tears and sell their car!
Boy, this place sure has mellowed....
but i still won't encourage it.
if the car makes enough power to spit flames naturally, then great, usually that is unavoidable after a point and it comes without guidance. if someone has a crappy n/a that they richened up to waste gas for the sake of popping some farts out the cans, then no, moronic and no one should help them, go buy a honda.
Last edited by RotaryEvolution; Jul 5, 2016 at 09:29 AM.
MECP Certified Installer
Joined: Feb 2009
Posts: 3,176
Likes: 3
From: Mesquite, TX-DFW
i lost my will to fight it.
but i still won't encourage it.
if the car makes enough power to spit flames naturally, then great, usually that is unavoidable after a point and it comes without guidance. if someone has a crappy n/a that they richened up to waste gas for the sake of popping some farts out the cans, then no, moronic and no one should help them, go buy a honda.
but i still won't encourage it.
if the car makes enough power to spit flames naturally, then great, usually that is unavoidable after a point and it comes without guidance. if someone has a crappy n/a that they richened up to waste gas for the sake of popping some farts out the cans, then no, moronic and no one should help them, go buy a honda.
As RE said, you either got a level the car does it naturally or your car is broken.
Joined: Jun 2006
Posts: 4,815
Likes: 24
From: Columbia, Tennessee
#1 in that sentence would make his car not want to idle and #2 in that sentence would be sure to make him NOT shoot flames.
Advancing the timing will cause the engine to burn more fuel during useful combustion, therefore leaving less unburned fuel in the exhaust....or blow his engine up.
*DISCLAIMER!*
*The below paragraph is at your own risk if you don't know what the **** you're doing!*
You can actually snag a few more HP out of the NA if you bump your timing 1-2 degrees above the stock baseline value. It moves your power curve down a smidge in the rpm range, which is great on a street car, you just lose a tad bit of the very top end. I run 2 degrees advance over stock on my car. I do have full exhaust modification with ported and non baffled exhaust, and super mild street port on the secondary ports, primaries are stock. It makes for an interesting idle.
It really depends on your engine. +2 on mine makes more power, +2 on yours might blow yours up. Hell, some of you with turbo motors might make more power by retarding your timing.
Like I said, not responsible for you blowing you engine up!
Advancing the timing will cause the engine to burn more fuel during useful combustion, therefore leaving less unburned fuel in the exhaust....or blow his engine up.
*DISCLAIMER!*
*The below paragraph is at your own risk if you don't know what the **** you're doing!*
You can actually snag a few more HP out of the NA if you bump your timing 1-2 degrees above the stock baseline value. It moves your power curve down a smidge in the rpm range, which is great on a street car, you just lose a tad bit of the very top end. I run 2 degrees advance over stock on my car. I do have full exhaust modification with ported and non baffled exhaust, and super mild street port on the secondary ports, primaries are stock. It makes for an interesting idle.
It really depends on your engine. +2 on mine makes more power, +2 on yours might blow yours up. Hell, some of you with turbo motors might make more power by retarding your timing.
Like I said, not responsible for you blowing you engine up!
its tough to blow up an n/a, i have seen some cars come in that were running 35* advance beyond factory spec.
you could hear audible pings at low loads but that still won't pop an n/a. while diagnosing one car i ran it hard at extreme advanced timing levels and the engine survived just fine, it however is not a good idea and it will cause damage if continued, but the result is usually just a very slow degradation of compression from seal chatter.
generally the most abusive pinging from advance is while free revving the engine with no load. strangely i can't even hear audible pinging no matter how far i advance the timing at full load with these engines.
disclaimer: all the above applies ONLY to naturally aspirated engines, try it with a turbo engine and i hope you bring a bus pass with you.
you could hear audible pings at low loads but that still won't pop an n/a. while diagnosing one car i ran it hard at extreme advanced timing levels and the engine survived just fine, it however is not a good idea and it will cause damage if continued, but the result is usually just a very slow degradation of compression from seal chatter.
generally the most abusive pinging from advance is while free revving the engine with no load. strangely i can't even hear audible pinging no matter how far i advance the timing at full load with these engines.
disclaimer: all the above applies ONLY to naturally aspirated engines, try it with a turbo engine and i hope you bring a bus pass with you.
Last edited by RotaryEvolution; Jul 5, 2016 at 09:57 AM.
MECP Certified Installer
Joined: Feb 2009
Posts: 3,176
Likes: 3
From: Mesquite, TX-DFW
its tough to blow up an n/a, i have seen some cars come in that were running 35* advance beyond factory spec.
you could hear audible pings at low loads but that still won't pop an n/a. while diagnosing one car i ran it hard at extreme advanced timing levels and the engine survived just fine, it however is not a good idea and it will cause damage if continued, but the result is usually just a very slow degradation of compression from seal chatter.
generally the most abusive pinging from advance is while free revving the engine with no load. strangely i can't even hear audible pinging no matter how far i advance the timing at full load with these engines.
disclaimer: all the above applies ONLY to naturally aspirated engines, try it with a turbo engine and i hope you bring a bus pass with you.
you could hear audible pings at low loads but that still won't pop an n/a. while diagnosing one car i ran it hard at extreme advanced timing levels and the engine survived just fine, it however is not a good idea and it will cause damage if continued, but the result is usually just a very slow degradation of compression from seal chatter.
generally the most abusive pinging from advance is while free revving the engine with no load. strangely i can't even hear audible pinging no matter how far i advance the timing at full load with these engines.
disclaimer: all the above applies ONLY to naturally aspirated engines, try it with a turbo engine and i hope you bring a bus pass with you.
these engines will run at almost any ignition angle, sometimes to the point that you don't even realize there is a major problem with the timing.
i've actually had engines run over 90* off time before. starting them can be a little tricky though when they are that far off.
timing these engines isn't even as productive as it is in piston engines, the difference in power of being 10 degrees retarded can be less than 5% total power loss, which is why it is better to be conservative than aggressive. the other adverse effects are larger though, such as grossly exaggerated emissions by being slightly too far advanced. this is why we have stepped ignition timing with a rather retarded idle timing curb. once off idle you could play with the CAS til you're blue in the face and see rather minor gains or losses.
i've actually had engines run over 90* off time before. starting them can be a little tricky though when they are that far off.
timing these engines isn't even as productive as it is in piston engines, the difference in power of being 10 degrees retarded can be less than 5% total power loss, which is why it is better to be conservative than aggressive. the other adverse effects are larger though, such as grossly exaggerated emissions by being slightly too far advanced. this is why we have stepped ignition timing with a rather retarded idle timing curb. once off idle you could play with the CAS til you're blue in the face and see rather minor gains or losses.
Last edited by RotaryEvolution; Jul 5, 2016 at 12:32 PM.
MECP Certified Installer
Joined: Feb 2009
Posts: 3,176
Likes: 3
From: Mesquite, TX-DFW
these engines will run at almost any ignition angle, sometimes to the point that you don't even realize there is a major problem with the timing.
i've actually had engines run over 90* off time before. starting them can be a little tricky though when they are that far off.
timing these engines isn't even as productive as it is in piston engines, the difference in power of being 10 degrees retarded can be less than 5% total power loss, which is why it is better to be conservative than aggressive. the other adverse effects are larger though, such as grossly exaggerated emissions by being slightly too far advanced. this is why we have stepped ignition timing with a rather retarded idle timing curb. once off idle you could play with the CAS til you're blue in the face and see rather minor gains or losses.
i've actually had engines run over 90* off time before. starting them can be a little tricky though when they are that far off.
timing these engines isn't even as productive as it is in piston engines, the difference in power of being 10 degrees retarded can be less than 5% total power loss, which is why it is better to be conservative than aggressive. the other adverse effects are larger though, such as grossly exaggerated emissions by being slightly too far advanced. this is why we have stepped ignition timing with a rather retarded idle timing curb. once off idle you could play with the CAS til you're blue in the face and see rather minor gains or losses.
When I was a youngin' I rebuilt a 4.3l V6 GMC s-15 with higher compression pistons and a street cam running with TBI. It could NEVER pass the ASM test due to NOx being 1,600ppm+. I could adjust the fuel pressure regulator to flood the engine and retard timing until the truck could barely run and it still wouldn't pass.
I just can't imagine a rotary making nearly that much NOx with its insanely long combustion chamber. I remember when I had to smog mine, it passed with flying colors in every category, especially NOx.
If my math is correct (which may not be) the rotors MAX rpm in relation to the eccentric shaft is only 2,666rpm at 8,000rpm redline. Isn't that going to give you a butt ton of time to burn some fuel considering under normal driving conditions, say 3,500rpm, the rotors only revolves 1,166 times. I know the rotor goes through a combustion power cycle for every rotation of the eccentric, but it is still moving slow in relation.
Dang, actually, at idle the rotor is moving at 250rpm. That's like 800 yrs time to ignite some fuel compared to a piston motor.
Now my head hurts.
Anyway, back to shooting flames...
As far as emissions, my educated guess would be NOx suddenly shoots through the roof?
When I was a youngin' I rebuilt a 4.3l V6 GMC s-15 with higher compression pistons and a street cam running with TBI. It could NEVER pass the ASM test due to NOx being 1,600ppm+. I could adjust the fuel pressure regulator to flood the engine and retard timing until the truck could barely run and it still wouldn't pass.
I just can't imagine a rotary making nearly that much NOx with its insanely long combustion chamber. I remember when I had to smog mine, it passed with flying colors in every category, especially NOx.
If my math is correct (which may not be) the rotors MAX rpm in relation to the eccentric shaft is only 2,666rpm at 8,000rpm redline. Isn't that going to give you a butt ton of time to burn some fuel considering under normal driving conditions, say 3,500rpm, the rotors only revolves 1,166 times. I know the rotor goes through a combustion power cycle for every rotation of the eccentric, but it is still moving slow in relation.
Dang, actually, at idle the rotor is moving at 250rpm. That's like 800 yrs time to ignite some fuel compared to a piston motor.
Now my head hurts.
Anyway, back to shooting flames...
When I was a youngin' I rebuilt a 4.3l V6 GMC s-15 with higher compression pistons and a street cam running with TBI. It could NEVER pass the ASM test due to NOx being 1,600ppm+. I could adjust the fuel pressure regulator to flood the engine and retard timing until the truck could barely run and it still wouldn't pass.
I just can't imagine a rotary making nearly that much NOx with its insanely long combustion chamber. I remember when I had to smog mine, it passed with flying colors in every category, especially NOx.
If my math is correct (which may not be) the rotors MAX rpm in relation to the eccentric shaft is only 2,666rpm at 8,000rpm redline. Isn't that going to give you a butt ton of time to burn some fuel considering under normal driving conditions, say 3,500rpm, the rotors only revolves 1,166 times. I know the rotor goes through a combustion power cycle for every rotation of the eccentric, but it is still moving slow in relation.
Dang, actually, at idle the rotor is moving at 250rpm. That's like 800 yrs time to ignite some fuel compared to a piston motor.
Now my head hurts.
Anyway, back to shooting flames...
Die Hard Fc
Joined: Oct 2009
Posts: 34
Likes: 0
From: kansas city
idle trick
Dang just thinking of the funny idle I should do a video of when it's fully warmed up. Fully warmed my engine idles at about 450-500 rpm but that is where it's happy, and the sound is freaking cool. There is actually a video on youtube of my engine idling below starter speed, lol. When you big exhaust your idle goes down but if you try and raise it to stock 750ish, you'll never get it.
a 160 thermostat believe it or not . auto parts stores don't have them in stock but most can order one for you .
i think.. . it gets eR running just a bit richer .
but not rich enough to wet the plugs .
a strange fix that one can only find by accident
Die Hard Fc
Joined: Oct 2009
Posts: 34
Likes: 0
From: kansas city
ad a quart of oil on each 1/8 of tank of fuel burned
set of plugs every 1/4 tank if they don't blow up and drop
you can get your idle higher 800 - 900 . with a simple trick
a 160 thermostat believe it or not . auto parts stores don't have them in stock but most can order one for you .
i think.. . it gets eR running just a bit richer .
but not rich enough to wet the plugs .
a strange fix that one can only find by accident
a 160 thermostat believe it or not . auto parts stores don't have them in stock but most can order one for you .
i think.. . it gets eR running just a bit richer .
but not rich enough to wet the plugs .
a strange fix that one can only find by accident
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Didn't. Ended up not bothering because I had just started working on the Cosmo and found out that it would be nearly $800 /month to insure. Not worth it. I still check the classifieds for a used XB12 but am also open to a Honda CX500 turbo or a Zero.
Good god man, $800/ month? I guess I'm lucky where I live. In my state, insurance is not required by law, since not many people per capita ride as much as in the warmer parts of the country.
I have my SV650 fully insured for $108 a year.
I have my SV650 fully insured for $108 a year.
I wish I was driving!
Joined: Dec 2001
Posts: 5,241
Likes: 84
From: BC, Canada
My R6 and 636 are each around $1000 for 6 months to insure, and BC is notorious for having high insurance rates.
you can get your idle higher 800 - 900 . with a simple trick
a 160 thermostat believe it or not . auto parts stores don't have them in stock but most can order one for you .
i think.. . it gets eR running just a bit richer .
but not rich enough to wet the plugs .
a strange fix that one can only find by accident
a 160 thermostat believe it or not . auto parts stores don't have them in stock but most can order one for you .
i think.. . it gets eR running just a bit richer .
but not rich enough to wet the plugs .
a strange fix that one can only find by accident
Die Hard Fc
Joined: Oct 2009
Posts: 34
Likes: 0
From: kansas city
i bet a R-12 freon can that
if jjwalker switched to a 160 stat
his idle would be 800rpm and the car would be happy
i've been switching stats for summer and winter six years now
works great for me
never had any issues
plugs are clean but not white
car never Ever smokes at all
im tellin ya it works
even works going backwards
if jjwalker switched to a 160 stat
his idle would be 800rpm and the car would be happy
i've been switching stats for summer and winter six years now
works great for me
never had any issues
plugs are clean but not white
car never Ever smokes at all
im tellin ya it works
even works going backwards
Information Regurgitator
Joined: Feb 2001
Posts: 1,994
Likes: 208
From: Sparta TN. United States
Idled fine around 750 to 800 rpm. After the streetport which included a med sized exhaust port(pineapple EP2) the idle was rough and a tad lower. I've got it idling between 800 and 900 now but it wasn't via the idle screw as it did nothing as you suggest. Had to play with the stop on the secondary butterflies but I had it all screwed up and idling at 1500 in the process. I think in the end I had break out the feeler gauges and reset the gap between them and the bore to the spec in the FSM to fix the idle, and then increase it slightly with a little larger gauge to get my idle up.
ETA: Always had a 180 degree thermostat, though the current one is a Stant. Previous was OEM.
Last edited by Dak; Jul 10, 2016 at 04:07 AM.
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
The rates are very high for new riders for the first couple of years, and the logic behind it makes no sense. A co-worker just bought an older 80s Honda cruiser. His insurance agent told him that to insure that bike is roughly twice the cost to insure a new crotch rocket (she quoted "Ninja"). After a few years that rate goes down, but there's no way I'm paying $6000 / year the first few years. Age brackets have a lot to do with it as well. As I'm under 41, I get a much higher rate.
To an insurance company, the fact that you want a bike means you're already halfway crazy, so they charge accordingly.
Although, to be fair, I can see their point.
I briefly worked at a dealership, just as the Yamaha FZR600 came out.
Their insurance claims adjuster told me that the average 600 sportbike lasted 27 days from sale to the first claim.
My advice (universally ignored) was to tell the new owner to strip all the plastic bodywork, turn signals and mirrors, store it away and drive the bike bare until it had been crashed the first time (which seemed inevitable).
After gaining some respect for the machine (and an appreciation of how terrible their skill set was), reinstall the frippery and carry on.
And yes, I have seen with my own two eyes people crash in the parking lot, not 100 yards from point of delivery.
Although, to be fair, I can see their point.
I briefly worked at a dealership, just as the Yamaha FZR600 came out.
Their insurance claims adjuster told me that the average 600 sportbike lasted 27 days from sale to the first claim.
My advice (universally ignored) was to tell the new owner to strip all the plastic bodywork, turn signals and mirrors, store it away and drive the bike bare until it had been crashed the first time (which seemed inevitable).
After gaining some respect for the machine (and an appreciation of how terrible their skill set was), reinstall the frippery and carry on.
And yes, I have seen with my own two eyes people crash in the parking lot, not 100 yards from point of delivery.