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I need some timing help

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36K views 107 replies 8 participants last post by  hartwill  
#1 ·
ok, so I have a 330 pro x cylinder ported by Neil, I am currently running a 2002 cr250 ignition with an adjustable timing plate. I set it up to fire at 5* BTDC it seemed to run good but would detonate at about 3/4 throttle under heavy load and even back my plug out occasionally. I thought this would be a good starting point as I did not know the timing curve on the 02 ignition because there is not a whole lot of info on it. since it was detonating i decided to retard the timing a little at a time to try and get it dialed in which changed where it seemed to detonate in the throttle position more toward half throttle, it also started to clack harder and harder. finally i decided to advance it again which returned me to less deto at a higher rpm, doing this also seemed to make the motor run quite a bit cooler. I guess I could be detonating from being too far retarded but I want to know what you guys think. with the more advanced timing it doesnt seem to back the plug out anymore but I am just not comfortable with my timing adjustment skills. anybody know where I can find a smaller degree wheel to make sure I am right on with my timing and or have a suggestion on where to set it? also any timing curve info compared to a 2001 ign or stock trx ign would really help. Or just someone located near Cleveland Ohio that wants to earn some cash doing it for me, lol.. thanks for your time and help in advance.
BTW 02 ign seems to work real well if I could just get it dialed in I think its just as well as 2001 and much cheaper to find, maybe this is why. lol
 
R
#2 ·
1986 500
 1993 500
 2000 250
 2000 125
 2001 250
 02 250 33%
 02 250 66%
 02 250 100%
 vortex 1
 vortex 2
 vortex 3
 vortex 4
 vortex 5
 vortex 6
 Vortex 7
 Vortex 8
 Vortex 9
 Vortex 0
 Dyna 00 1
 dyna 00 2
 dyna 00 3
 dyna 00 s
 dyna 01 1
 dyna 01 2
 dyna 01 3
 dyna 01 s
 MSD Enhancer cr125/250 on cr500 fly
 MSD Enhancer cr125/250 on cr500 fly
1986 TRX 250R
1988 TRX 250R
MSD TRX250R Enhancer
 MSD TRX250R Enhancer
 Vortex map 1
 Vortex map 2
 Vortex map 3
 Vortex map 4
 Vortex map 5
 Vortex map 6
 Vortex map 7
 Vortex map 8
Arctic Cat 900 2004
 remapped AC 900
250
 cr500
 cr500
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 cr500
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 cr500
 7
 7
 7
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 7
 7
 7
 full advance
 full retard
 full advance
 full retard
 TRX 250R
 TRX250R
 TRX250R
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 TRX250R
 TRX250R
 TRX250R
 TRX250R
500
 9
 9
 9
 7
 7
 7
 7
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 7
 7
 7
 24
 24
 24
 24
 24
 24
 24
 24
 12.5
 13
750
 9
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 7
 7
 7
 7
 7
 7
 25
 25
 8
 18
 23
 23
 24
 24
 24
 24
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 24
 24
 12.5
 13
1000
 10
 9
 9
 9
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 10
 7
 7
 7
 7
 7
 7
 7
 7
 25
 25
 20
 23
 23
 23
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 24
 24
 24
 24
 24
 12.5
 13
1250
 14
 9
 30
 9
 3
 1
 3
 3
 3
 3
 7
 7
 7
 7
 7
 7
 7
 7
 25
 25
 23
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 23.5
 15
 17.5
1500
 19
 24
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 30
 20
 4
 13
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 21
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 16
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 20
 20
 16
 18
 25
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 23
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1750
 23
 24
 20
 30
 20
 12
 14
 15
 14
 14
 14
 21
 21
 21
 21
 25
 25
 23
 23
 22
 20.5
 24
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 24
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 24
 21.5
 22
 24
2000
 27
 24
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 20
 15
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 15
 21
 21
 21
 21
 25
 25
 23
 23
 22
 20
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 24
 24
 24
 24
 20
 26
 26.5
2250
 27
 24
 20
 30
 20
 18
 15
 15
 15
 15
 15
 21
 21
 21
 21
 25
 22.5
 23
 23
 21.5
 19.5
 24
 24
 24
 24
 24
 24
 24
 20
 26
 26.5
2500
 27
 24
 20
 30
 20
 10
 10.8
 16
 18
 15
 15
 15
 15
 15
 21
 21
 21
 21
 25
 21
 23
 23
 21
 19
 24
 24
 24
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 20
 26
 26.5
3000
 26.5
 24
 20
 30
 20
 18
 15
 15
 15
 15
 15
 21
 21
 21
 21
 24
 20
 22.5
 22.5
 20.5
 18.5
 24
 24
 24
 24
 24
 24
 24
 20
 26
 26.5
3250
 26.5
 24
 20
 29.5
 20
 18
 15
 15
 15
 15
 15
 21
 21
 21
 21
 22
 19
 22
 22
 20
 18
 24
 24
 24
 24
 24
 24
 23
 20
 26
 26.5
3500
 26
 24
 20
 29
 20
 18
 12
 15
 15
 15
 15
 21
 21
 21
 21
 21.5
 18.5
 22
 22
 19.5
 17.5
 24
 24
 24
 24
 24
 23.5
 22.5
 20
 26
 26.5
3750
 25
 24
 20
 28.5
 20
 18
 9
 15
 15
 15
 15
 21
 21
 21
 21
 21
 18
 22
 22
 19
 17
 24
 24
 24
 24
 24
 23
 22
 20
 25
 26.5
4000
 25
 24
 20
 28
 20
 19
 13.6
 13.6
 18
 6
 15
 15
 15
 15
 21
 21
 21
 21
 21
 21
 17
 19
 20
 21
 17
 19
 20.5
 17.5
 22
 22
 18.5
 16.5
 24
 24
 24
 24
 23.5
 22.5
 21.5
 20
 24.5
 26.5
4250
 25
 24
 19.5
 27.5
 20
 18
 4.5
 14
 14
 15
 15
 20.5
 20.5
 20.5
 20.5
 20
 17
 22
 22
 18
 16
 24
 24
 24
 24
 23
 22
 21
 20
 24
 26
4500
 25
 24
 19
 27
 20
 18
 3
 13
 13
 14
 14
 20
 20
 20
 20
 20
 16.5
 22
 21
 18
 15.5
 24
 23.5
 23.5
 23.5
 22
 21.5
 21
 20
 23
 25.5
4750
 25
 23
 18.5
 26.5
 20
 18
 2
 11
 12
 13
 13
 19.5
 19.5
 19.5
 19.5
 20
 16
 22
 21
 18
 15
 24
 23
 23
 23
 21
 21
 21
 20
 22.5
 25
5000
 25
 22
 18
 26
 19.5
 18
 13.5
 12
 18
 1
 9
 11
 12
 13
 19
 19
 19
 19
 20
 21
 17
 19
 19.5
 15.5
 21.5
 21
 17.5
 14.5
 23.5
 19.5
 21
 22
 20.5
 20.5
 20.5
 20
 22
 24.5
5250
 24
 21.5
 17.5
 25
 18.5
 18
 1
 7.5
 9.5
 11.5
 12.5
 18
 18
 18.5
 18.5
 19
 15
 21
 21
 17
 14
 23
 19
 19
 21
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 20
 20
 20
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5500
 23
 21
 17
 24
 18
 18
 1
 6
 8
 11
 12
 17
 17
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 18
 18.5
 14.5
 21
 20.5
 16.5
 13.5
 22.5
 17
 17
 19
 19
 19.5
 19.5
 19.5
 20
 22.5
5750
 22
 20
 16.5
 22.5
 17.5
 18
 1
 5
 7
 9.5
 10.5
 15
 15.5
 17.5
 17.5
 18
 14
 21
 20
 16
 13
 22
 15
 15
 17
 18
 19
 19
 19
 18.5
 21
6000
 21
 19
 16
 21
 17
 18
 12.6
 9.8
 18
 1.5
 4
 6
 8
 9
 13
 14
 17
 17
 17.5
 13.5
 20
 19
 15.5
 12
 21
 11.5
 12.5
 14
 17.5
 18.5
 18.5
 19
 17
 19.5
6250
 20.5
 18
 15.5
 20
 16.5
 17.5
 1.5
 3.5
 5
 7
 8
 11
 12.5
 16.5
 17
 17
 13
 19
 17
 15
 11.5
 20
 8
 10
 11
 17
 18
 18
 19
 15.5
 18
6500
 20
 17
 15
 19
 16
 17
 2
 3.5
 5
 6
 7
 9
 11
 16
 17
 16.5
 12.5
 18.5
 16.5
 14.5
 11
 19
 6.5
 8
 9.5
 16
 17.5
 17.5
 17.5
 13.5
 17
6750
 19
 16
 14.5
 18
 15
 16
 2
 3.5
 5
 5.5
 6.5
 8
 9.5
 14
 17
 16
 12
 18
 16
 14
 10
 18
 5
 6
 8
 15
 17
 17
 17
 11.5
 16
7000
 18
 15
 14
 16.5
 14.5
 14.3
 10
 8
 15
 2.5
 3.5
 5
 5
 6
 7
 8
 12
 17
 15
 15
 11
 13
 16
 11.5
 17.5
 15.5
 14
 9.5
 17.5
 5
 6
 7.5
 14.5
 16.5
 16.5
 16.5
 10
 14.5
7250
 17
 14.5
 12
 15.5
 14
 14.5
 2.5
 3.5
 4.5
 4.5
 6
 6.5
 7.5
 11
 16
 16
 11
 17
 15
 14
 9
 17
 4
 6
 7
 14
 16
 16
 16
 8.5
 13
7500
 16
 14
 12
 14.5
 14
 14
 2.5
 3.5
 4
 4
 6
 6
 7
 10
 15
 14
 14
 9
 11
 15.5
 10.5
 16.5
 14.5
 13.5
 8
 16
 4
 6
 7
 13.5
 15
 15.5
 16
 9
 12
7750
 15
 13
 12
 13.5
 13
 10
 8
 5.5
 13
 2.5
 3.5
 4
 4
 6
 6
 7
 9
 14.5
 13
 14
 10
 12
 15
 10
 16
 14.5
 13
 7
 15
 4
 6
 7
 13
 14
 15
 16
 9.5
 11.5
8000
 14
 12
 12
 12.5
 12
 12
 2.5
 3.5
 4
 4
 6
 6
 7
 8
 14
 14.5
 9
 15.5
 14
 12.5
 6.5
 14.5
 4.5
 6.5
 7.5
 12
 14
 14.5
 15.5
 10
 11
8250
 13.5
 11
 12.5
 12
 11.5
 11.5
 2.5
 3.5
 4
 4
 6
 6
 6.5
 7
 13
 14
 8
 15
 14
 12
 6
 14
 5
 7
 8
 11
 14
 14
 15
 10
 11
8500
 13
 10
 13
 12
 11
 11
 2.5
 3.5
 4
 4
 6
 6
 6
 6
 12
 15
 16
 12
 14
 14
 7.5
 14
 14
 12
 5.5
 13.5
 5.5
 7.5
 8.5
 10.5
 13.5
 14
 14.5
8750
 12
 9
 12
 12
 10.5
 10
 2.5
 3.5
 4
 4
 5.5
 6
 6
 7
 11.5
 14
 7
 13
 14
 12
 5
 13
 6
 8
 9
 10
 13
 14
 14
9000
 11
 8
 11
 12
 10
 7
 5.9
 3.4
 9
 2
 3
 4
 4
 5
 6
 6
 8
 11
 13.5
 6.5
 12.5
 14
 11.5
 4.5
 12
 7
 8.5
 9.5
 10
 12.5
 13.5
 13.5
9500
 10
 11
 7
 9
 13
 6
 12
 14
 11
 4
 11
 8
 9
 10
 10
 12
 13
 13
10000
 4
 2.9
 1
 10
 12
 9
 11
 MSD recommends +7 degree's advance at stator
10500
 13
 16
 12
 14
 18
 the numbers above do NOT show this advance
11000
 16
 18
 14
 
R
#3 ·
The numbers for the dyna and for the 2002 cr250 ignition were given to me I can not comment on them any more then what you see

you need to by a 2stroke timing light and put a degree wheel on the motor and find TDC and mark the flywheel and check where your base timing is. All the numbers in the world are not going to help you until you do this.
 
#4 ·
If I'm reading or understanding this correct it seems a backwards from how I was told Two stroke ignitions work. I thought they were advanced timing at lower rpm then retarded a little through mid range and then advanced again at high rpm. This is also how my MAC timing light reads on my motor. Maybe that's why I need a two stroke light.
Any suggestions on where to buy one and or a degree wheel? Or where I can set it to be correct off my dial indicator? I don't think that setting it off the indicator measurement would be as accurate though as I'm not positive at which part of the rotor pick up it fires.. thanks again.
 
R
#6 ·
You are correct 2 stroke timing curves do start out high at running speeds but they many times are retarded at the very low rpms for starting purposes to prevent kickback.

The 2002 map shows throttle positions 33-66-100% the timing curve is different for each position. Like I said those numbers were given to me so I do not know how accurate they are or if the 2002 even had a throttle position sensor that year but I know at some point they did have them.

If you degree your flywheel with the 0-30 degrees you do not need a light like I have a normal light can be used buts its kind of a pain to mark one out. Just marking TDC is easy though.

Motion pro sells the smaller degree wheels

I use this light and have excellent luck with it

Amazon.com: Equus 5568 Pro-Timing Light with Tool Case: Automotive

Image
 
R
#10 ·
checked and confirmed that ESR's timing plate maybe will add but 1-2 degrees of timing to the numbers above for the Cr125 and cr250 stators mounted on a TRX case.
It may actually not add any by design but it is possible because of machining tolerances a 1-2 degree advancement is seen.
This amount of advance will be added to every point along the scale the same if you decide to add or subtract timing by moving the stator along the slots, it does it across the board.
 
R
#12 ·
The small metal factory centering plate(washer)was installed, basicly this disproves that there is any advance built into the ESR plate.

If you dont mind PMing me your e-mail I will send the excel sheet and it includes all the zeros that did not transfer on my copy and paste. maybe it will work better with google. I am really busy right now and if I try to mess with this I will probably spend forever figuiring it all out.

thanks
Dave
 
R
#14 ·
yes running the timing to far retarded can over heat the side of the piston. I feel with the cr250 cdi they should be run with plus 4 degrees for most setups but testing and reading the plug strap heat is always the way you come up with the correct needs for your motor because allot does depend on head design.

I was looking at ESR alky head for the 330 (345 with +4 stroke) on my inlaws bike and they do not run allot of squish band width on them(40% of the bore) .040 squish clearance at the edge with a tapered clearance(which means it get larger toward the center which I do not like) , compression came in at 15.9 to 1 uncorrected small squish band widths and loose or tapered clearances will take more motor timing than a wide squish band and parallel squish band.
 
C
#18 · (Edited)
This is my thinking as well.
Quite a few years ago, daughters 330R spit the spark plug out.
Mater of fact, it is Hartwills 330 cylinder that he has, but what I did afterwards & when back at the shop, I pulled the plug & used a screw in plug hole dial indicator to find TDC, then once I found that, I used soap stone to put a mark on the case for TDC in line with the TDC mark on the outside of the flywheel, TDC was found.
Then with a timing light hooked up, cranked the engine up & checked to see how close the two soap stone marks lined up. MAN, it was probably close to 3/4" of an inch from each other, but I had the CR stator plate set at just a bit past center to advanced setting. Must have been around 20~25* advanced timing so no wonder it spit the spark plug out.

Next thing I did, pulled the flywheel, I loosed the bolts holding the ESR adapter plate to the case, took all the play out of the mounting holes by rotating it counter clockwise & locked it down, then loosed the two bolts holding the CR ignition stator plate & rotated it counter clockwise as far as it would go, (no metal plate in place on the bottom hole on the CR stator plate) & locked it down.
Timing light still hooked up, cranked the engine & still timing light was showing timing marks were off around 3/16 to 1/4" apart from each other in the advance mode.
So with that much distance between the two marks, 3/16 to 1/4", would be around 8 to 10* advanced ignition timing.
Heres the klincher though, I dont know which year CR250R ignition system is on my daughters 250R, was on the bike when we bought it.

I do believe, the ESR adapter plates have advance timing already machined into them, reason being, from what I have found from that testing & ignition setting & from the fact ESR does so many 250R alky engines that need a lot of advanced timing for those engines to run proper.
I could be wrong, but a lot of folks that have changed over to the CR ignition are having the same ignition problems trying to get it timed right, so somethings got to be wrong for so many to have that same problem.
Since her ignition has been set as far retarded as it can be set, we've not had anymore issues with spark plug being backed out or her hearing deto.

Another thing I want to add, disregard, any timing markings to set the ignition timing by, that you see on the CR stator plate or the ESR adapter plate, because they have nothing to do with the ignition timing settings for the TRX250R engine.
Neil
 
N
#17 ·
o right so what would the timing be in degrees with the stator fully ccw off the elongated slot on the esr adapter plate of a 2001 ignition?
i always thought advancing the timing increases engine heat with it sparking ealier before tdc it gives the flame more time to spread increasing heat but with less advance it controlls the heat in a smaller area with a smaller flame propogation resulting in less engine heat in theory is that true?
 
N
#19 ·
that's what i did neil when i took your advice and also checked the anneal line on the spark plug strap after a plug chop process and the anneal line looked near enough spot on in this position so i will settle with that. i never had a spark plug coming loose though, but then you was further advanced than the original centre position.
i'm sure this setting will make the engine more reliable and the spark plug to work great and less heat in the cylinder.
 
R
#21 ·
All I can say is I have a TDC mark on the flywheel with a permenant pointer mounted inline with it.
I have a 2 stroke timing light that has digital timing and rpm display and I have recorded my findings.
These finding just so happen to support my findings done on my bench tester.
A 2001 cr250 cdi and 2001 cr125 cdi were both checked with results that supported the bench test results using the same timing light.

I can see no flaws in my system, if anyone can point out any I will be more than accommodating in changing them.

But until then I stand by all the curves I have posted over the past few years except for the 2 I mentioned another person gave me and by the looks of it the cr250 listed as a 2002 is not a 2002 but some later year with a TPS
 
C
#22 ·
I cant say the numbers you are listing are wrong, cause I have no way of testing like you do, but I believe the real life difference it coming in when the TRX250R engine is tested & dialed & indicated in at TDC, just a bit different in how it is mounted on the engine.

Maybe we need to take this to the other site rsss, some bigger brains on there than mine I know for sure. You know, where is ol Teamgeeks6 when you need him :lol:.
Neil
 
N
#26 ·
uns said:
I have a 2000 CR ignition on my trx. I'm hoping to find time next weekend to find TDC, and maybe print out something like a degree wheel from the internet. I have a 2/4 stroke selectable digital timing light like RS somewhere around the shop, so everything should be a snap if I can find the hour or two.

I think we have this mostly figured out though. Neil's 20 degree comment is right exactly in line with the curves RS has provided. RS's spreadsheet shows that at around idle to 3k rpms the advance SHOULD be 20 degrees. It is what its supposed to be stock, and it is what neil saw. The disconnect must be in Neil's belief that he should see 0 degrees advance in this range.

I agree that this doesn't reconcile well with the spark plug being blown out, but maybe it was for a different reason?

And here is the latest timing spreadsheet on google docs. I'll try to make it a bit less unwieldy tonight after work.

https://docs.google.com/spreadsheet/pub?key=0AoIOC91Tnf9EdFA5bjdabmdxZjM3R2FlczJrOXd3d1E&output=html
Click to expand...
i'm with ya fella, so the 20 degree stock ignition timing before tdc is actually what you'd get from a cr 250 ignition in the centre position were it would be if the thin plate was still installed. might be worth a play further advancing the timing slightly from 20 degrees get it between the cr250 and 125 figures that would make a difference aslong as detonation and to much heat doesn't occur
 
N
#28 ·
uns said:
Yea. It's all clicking together well because the curve RS has for the cr250 is a few degrees less advanced across the entire range, and he said the plate adds a degree or two. I'm starting to wonder if ESR didn't make that plate to advance that extra 1-2 degrees to offset the loss of those degrees on a CR. So it's looking like ESR's plate with that center washer almost exactly matches the 250r's amount of advance, maybe being a few degrees behind at the bottom and a degree ahead at the top, give or take.
Click to expand...
yer i can clearly see that now i've compared across from the 01 cr250 to the 88 250r ignition from idle (ish) at 1500 revs the cr ignition is 3 degrees less advanced, and also compared at other revs say 7000 and 9000 revs there still 1 to 2 degrees less advanced so advancing the timing 3 degrees more from the centre position were that thin plate would leave you would be a good starting point wouldn't you agree, i know being 1 to 3 degrees down on advanced wouldn't loose alot with it being a better igntion system but you might gain abit having it set that little bit more.
 
N
#31 ·
that oragne line looks more like the 88 250r identical timing numbers near abouts anyway from the cr 250 +2
but what's the +2 mean? and +2 from what? is it +2 from the centre position of the stator so from a standard point of view you'd remove that thin plate
leaving you with the stator in the centre of that hole is it +2 degrees advanced from there to make it near identical to the 88 timing figures?
 
This post has been deleted
R
#33 · (Edited)
remember there may a machine tolerance between the factory stator plate,flywheel timing tab,crank end key way, pickup mount position and ESR machine tolerances.
This is why if you were to take a look at any of my maps and set your base timing you need to install a pointer and mark the flywheel to true TDC.
If you do not then your timing may be slightly different than what I have found, and what I have found is when the factory plate is installed it was about 1-2 degrees advanced from the timing maps that I have posted.
Remember the maps that I have posted is the advance produced by the CDI not what you may or may not add or subtract at the stator plate.
So the Orange line with +2 degrees is roughly what was seen on our bike that we tested yesterday this does not mean your bike will be exactly the same but I do not think you will see more than a 1-2 degree difference than what we have found.
 
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