can you adjust timing on a 250r?

[william16339]

hi i was just wondering, could you adjust the timming on a 85/86 atc 250r? thankyou/

[rg97]

I don't know much about a 250r, but they may make adjustable timing plates.
EDIT: looked it up and found these:http://www.ebay.com/itm/Honda-ATC-TRX-250R-250-R-Billet-Timing-Advancer-/221307379169?pt=Motors_ATV_Parts_Accessories&hash=item3386f29de1&vxp=mtr

[3wheelrider]

The IGNITION timing cannot be adjusted or slotted out on a stock machine. But you can buy a adjustable-(preffered) or non adjustable C.B bearing holder (billet) which is where the pickup mounts to. Then you can adjust it + or -...... R.P.M. sells one but they are a bit pricey nowadays.

[3wheelrider]

I don't know much about a 250r, but they may make adjustable timing plates.
EDIT: looked it up and found these:http://www.ebay.com/itm/Honda-ATC-TRX-250R-250-R-Billet-Timing-Advancer-/221307379169?pt=Motors_ATV_Parts_Accessories&hash=item3386f29de1&vxp=mtr

Yep -But that one is non-adjustable.

[82 250r]

The timing for the 85-86 250R is not adjustable from the factory. However, there are aftermarket products that allow you to do it.
I have this from RPM and it works great.

http://www.team-rpm.com/honda-trx250r-timing-advance-unit.html


http://i282.photobucket.com/albums/kk261/bmwic155/P1000883_zps361f4938.jpg (http://s282.photobucket.com/user/bmwic155/media/P1000883_zps361f4938.jpg.html)

[RIDE-RED 250r]

I'm not sure a stock-ish 250r would see alot of benefit from the adjustable ignition... I could be wrong.

But one thing I can tell you is, BE CAREFUL and know what you are doing when playing with your timing! I have not yet run adjustable timing on either of my R's to this point, but have seen where others sometimes have issues. It can be tricky business and can cost you a perfectly good top end if you don't get it right.

[jeffatc250r]

You can take a chainsaw file to the stator plate, kinda the redneck way of doing it, but it cost you nothing more than a half hr of your time. I have done this on mine and so has my friend, throttle responce is better. Your gonna have to play around to find the sweet spot. Remember, a little goes a long ways. This was done on mine prob 10yrs ago with no ill effects
If it gets to be a bear to start, back er off a bit

[El Camexican]

You can take a chainsaw file to the stator plate, kinda the redneck way of doing it, but it cost you nothing more than a half hr of your time. I have done this on mine and so has my friend, throttle responce is better. Your gonna have to play around to find the sweet spot. Remember, a little goes a long ways. This was done on mine prob 10yrs ago with no ill effects
If it gets to be a bear to start, back er off a bit


Do you guys with the ability to make adjustments advance or retard your timing? How many degrees till you start to see a difference?

[RIDE-RED 250r]

You can take a chainsaw file to the stator plate, kinda the redneck way of doing it, but it cost you nothing more than a half hr of your time. I have done this on mine and so has my friend, throttle responce is better. Your gonna have to play around to find the sweet spot. Remember, a little goes a long ways. This was done on mine prob 10yrs ago with no ill effects
If it gets to be a bear to start, back er off a bit

I don't believe altering the stator position will change ignition timing. The magnet that trips the pulse generator on the flywheel is on the outside of the flywheel. The pulse generator is also mounted outside the flywheel on the CB carrier. Moving the pulse generator is what controls ignition timing.

[barnett468]

hi i was just wondering, could you adjust the timming on a 85/86 atc 250r? thankyou/Hello william16339;

I think the comments ride-red 250r posted, are good and might at least be helpful to others that read this thread even if these are things you might already know, therefore I thought I would simply add a little more info related to ignition timing.




OFFSET KEYWAY - In addition to the two items mentioned above by others, you can buy offset keyway's to advance the timing. They cost around $2.00 each and simply go on the crank in place of the orig keyway for the flywheel. They are available at some industrial hardware supply stores and possibly Graingers. See photos and links for them in the link below.

http://www.google.com/search?q=offset+keyway&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a


Here's a package with 6 different offsets for a whopping $5.71. Check for proper size.

http://www.georgebark.com/Offset-Keyway-Clone-Keyway.htm





I'm not sure a stock-ish 250r would see alot of benefit from the adjustable ignition... I could be wrong.
Advancing the timing 2 degrees will result in an almost imperceptible increase in performance, but as long as the stock muffler has been replaced with a non spark arrestor type it will help.





But one thing I can tell you is, BE CAREFUL and know what you are doing when playing with your timing! I have not yet run adjustable timing on either of my R's to this point, but have seen where others sometimes have issues. It can be tricky business and can cost you a perfectly good top end if you don't get it right.
A completely stock 250r is on the threshold of detonation with 91 octane in hot temps when ridden hard, therefore, increasing the timing will push it over the edge under these conditions which as ride-red 250r mentioned, may cause "issues" which are mainly piston related.

If the stock muffler is removed, increasing the timing 2 degrees will have a more noticeable effect than increasing it with a stock one, however you must increase the jetting size if the stock muffler is removed whether the timing is increased or not.

If you advance the timing you will likely need to increase your main jet size by 1 and raise the needle position by 1 if your bike is currently perfectly jetted which most are not.

If you advance the timing you might have to increase your fuel octane.

If you increase your compression from stock you will likely need to run more than 91 octane.

If you run increased timing AND increased compression like some do, you will positively need to run fuel with an octane rating of more than 91. The exception to this is E85 corn gas which has a detonation resistance equivalent to around 100 octane regular gas but it has less energy than a comparable regular gas.

At least some "production” gas has a very inconsistent octane rating. This means that just because you buy Shell one day that had a true 91 octane rating, there is no guarantee that the next time you buy it or gas from Union 76, that the octane will be as high even though it says right there on the pump that it is.

This is another reason some bikes that are built for high performance and on the threshold of detonation, occasionally blow up for no apparent reason.

Advancing the timing 4 degrees is not something I would recommend for any non pro or non rich rider. This is because, even though a non pro might be able to feel the difference when it is done on a modified bike, imo it is not worth the additional risk in detonation it causes.





I don't believe altering the stator position will change ignition timing. The magnet that trips the pulse generator on the flywheel is on the outside of the flywheel. The pulse generator is also mounted outside the flywheel on the CB carrier. Moving the pulse generator is what controls ignition timing.This is correct and imo [as if that matters] another good point to bring up. You can turn the stator upside down and your timing will not change.



HAPPY HOLIDAYS!

:Bounce

[C.J]

Will's bike has the thinner CR head gasket, FMF pipe and DG can and is soon to be ported if I remember right what he told me. Think he's running the stock carb but I know he's got it as close to perfect as he can get. He's pretty good with engines, can't lie.

Sorry if I'm stepping on your toes any bro!

Edit: not stock carb. PJ38

He's a buddy of mine outside the forum is how I know these things lol

[82 250r]

Do you guys with the ability to make adjustments advance or retard your timing? How many degrees till you start to see a difference?

From what i understand the 250r left the factory de-tuned by 4 degrees. (ie 4 degrees retarded)
There is no way Honda can tune all their products for all areas of the world, in all riding conditions, for all riding styles, with different blends of fuel etc.etc. The solution? They tune them for the lowest common denominator.

I believe a stock motor, using pump gas at sea level, can benefit from advanced timing although i have not done it myself.

We have to tune our motors based on the combination of parts, how it was built, and for the intended use.
For example, my cylinder is ported for low end trails, has a low/mid pipe, stock silencer, stock gears/tires, to be ridden at 5000'-10,000' elevation, with 110 octane.

Obviously i can use some timing with this combo...but how much? The answer is really trial and error. So far i have advanced it 4 degrees and can probably go another 2-3 before I'm done tuning.

Those with high rev motors need to be very careful advancing the timing. In fact, it may help to retard the timing especially if the port timing has been changed or you have an aftermarket CDI with a high rev limiter.
If you choose to advance your timing, go small (1-2 degrees) and watch for detonation. Advanced timing also can make a motor run lean so check your jetting often.

Marc

[Liquid-Darkness]

I thought that I read somewhere that adjusting your spark plug gap would change the timing a little bit.. Shrug Merry Christmas!!