Observations on CDI's

[CJM]

So since we continually argue about ignition systems Id like to share my findings on a few different CDI's I have used.

1. Stock. With my setup I have good power all around. I can rev out 2nd, 3rd and so on freely. 1st is rather short but I attribute it to my gearing setup.

2. Pro com. For me it doesnt work very good. Power is all in last few thousand rpm and I had to rev it out in every gear for it to make power. I HIGHLY dislike it. But maybe a stock or such 400 would work with it better?

3. White Bros. It works good, BUT and a big BUT. I rev out WAY to easy, it seems like Im hitting the limiter crazy fast, 1st is near useless unless I want to putt and 2nd revs out so quick that I can only use it on tight trails. I mostly rode in 3rd gear and higher. Power comes on in the last half or so of the throttle, almost rides like a 2 stroke power valved bike.

So in my experience, with a totally worked bike some CDI's do help-but at least in my case the benefits werent so good. For instance if I wanted to do jump in 2nd gear and ride up a hill or something (step up) it would rev out too easy and I had to use 3rd and it was a pain as you needed slightly more take off distance to gain the speed to be in 3rds power range. I also found that it made the bike want to rev out too easy. Im sticking to the stocker. I sure as hell am not paying for a programmable ignition as they are upwards of 300 bucks.

[01boneless]

nice write up marc.

[CJM]

thanks bud.

So I believe ive debunked that these things are worth it no?

Anyone has another brand Id happily try it if you send it to me. I PROMISE to return it to you postage paid.

[01boneless]

Originally posted by CJM
thanks bud.

So I believe ive debunked that these things are worth it no?

Anyone has another brand Id happily try it if you send it to me. I PROMISE to return it to you postage paid.
more less lol i think on stock motors there useless , on built eh a little but they push the motor hard. the stock limet after its power is done being made is the safest spot to stop the rpm to avoid damage imho i think there hard on a motor, and even though some say the very big built engines can benifit maybe true but, these bigger motors usually have aftermarket valves,or oversize valves (usually heavier then stock) the chance of valve float is always at high rpm's... and heavier valves chance it a little more (HD springs help) so once your at highest rpm on heavier valves theres a chance of valve float then add how ever many rpm to that ,that the a.m. cdi makes and your cutting it close like i said just my .02 cents but imo there not worth it hope that made sence lol

[CJM]

I totally agree, in some cases they may work or maybe a different cdi brand will react differently (already evidenced by the procom I tried vs white bros). In the end I feel that if anything it was hurting my power because it revved too quickly to take advantage of the usable power-even with a smaller rear sprocket for speed so I had longer gears it didnt help.

[Rohr397]

I think the only company I would trust for this type of thing is Tokyo Mods. A couple buddies of mine have them in their stock dirt bikes and WOW is all I have to say. They're the rare exception, idk if they'd be good on a 400ex but they're great on Unicam engines for sure.

Here's a link to the 400ex stuff:
http://www.tokyomods.com/honda/1999-2006%20TRX400EX.html

I think the cam chain tensioner is a first lol I've never heard of someone buying one aftermarket but it'd be interesting for sure.

[CJM]

Im game to try something else or at least all ears to hear someone else experiences with the way the quad revs with an aftermarket CDI.

As for the tensioner, Im sorry but if you manually adjust it-its all on you if there isnt enough tension. Spring loaded means its ALWAYS adjusted and failure rate is slim. Honestly I have NO idea how mine is still good, the quad was 4 years old when i got it and Im sure its original. yet everytime I check it, its fine. I might replace it for the heck of it just to be safe.

[01boneless]

Originally posted by Rohr397
I think the only company I would trust for this type of thing is Tokyo Mods. A couple buddies of mine have them in their stock dirt bikes and WOW is all I have to say. They're the rare exception, idk if they'd be good on a 400ex but they're great on Unicam engines for sure.

Here's a link to the 400ex stuff:
http://www.tokyomods.com/honda/1999-2006%20TRX400EX.html

I think the cam chain tensioner is a first lol I've never heard of someone buying one aftermarket but it'd be interesting for sure.
most after market cdis are procoms with a diffrent sticker or the 250 bike cdi. either way they all serve the same purpose and claim the same effects
and im with cjm on the tentioner if u forget to adjust it your chain can stretch if u go to tight it can break. also i love how they claim the manual tentioner adds horsepower lol

[quadmanw]

Marc, I would love to send you my Sparks and I would def trust you with it, but it is just that time of the season where I am riding constantly. I really like this CDI and think that you would too. I never seem to rev out to easy

[TheAwesomehonda]

Originally posted by Rohr397
I think the only company I would trust for this type of thing is Tokyo Mods. A couple buddies of mine have them in their stock dirt bikes and WOW is all I have to say. They're the rare exception, idk if they'd be good on a 400ex but they're great on Unicam engines for sure.

Here's a link to the 400ex stuff:
http://www.tokyomods.com/honda/1999-2006%20TRX400EX.html

I think the cam chain tensioner is a first lol I've never heard of someone buying one aftermarket but it'd be interesting for sure. The problem i see with that ignition in the link is that it don't say what years there for??? They changed them in 05.

[Stickman400]

I may send you my Big Gun CDI also CJM. Will the '05 work in a '99-'04? Idk if having the reverse limiter in it will jive with the others not having a reverse gear. I don't mind not having it for a week or so, I'll just throw the stocker back in and see if I notice a drop in power or anything.

[CJM]

Originally posted by quadmanw
Marc, I would love to send you my Sparks and I would def trust you with it, but it is just that time of the season where I am riding constantly. I really like this CDI and think that you would too. I never seem to rev out to easy

If you wanted to Id happily check it out. But I hear ya. I might drop the cash on one for the heck of it sooner or later-but right now a 450r might be coming home with me sooner than later :D

Sadly Stick the 05 will not work with the older 99-04 :(

[Rohr397]

Yeah they really focus on the Unicam high performance engines. I'm sure a phone call would clear up any questions though.

As for the tensioner that's what I figured, seems like something you would install if you were going to rebuild the engine after every race. Again I think they threw it out there for 400ex's but it's really meant for one of their completely built engines.

Boneless since you've got a 450r definitey check out their stuff for that. The carb work is supposed to be amazing and there's lots more too.

***I'm not sponsored by them I just really have liked their products on the Crf250 and 450 and not a lot of quad riders know about them. Thought Id spread the word.

[TheAwesomehonda]

Originally posted by Stickman400
I may send you my Big Gun CDI also CJM. Will the '05 work in a '99-'04? Idk if having the reverse limiter in it will jive with the others not having a reverse gear. I don't mind not having it for a week or so, I'll just throw the stocker back in and see if I notice a drop in power or anything. No man the 05 wont work in the older model. I tried it and the quad wouldn't start but then when I put in back on my 05 I no longer had a reverse governer. :confused: And if you put put the 99-04 on the 05+ it will work but once again it wont have a governer in reverse. I thought that was really weird.

[Jayskee]

CJM- correct me if wrong, but Im pretty sure a lot of these companies are using the CDI box off the 250f dirtbike? I just tried searching it and can't find the info now. Thats why people say with the whitebrothers if u have trouble starting it use the stock box and once the bike is heated up then switch it over.

[JOHNDOE83]

Originally posted by Jayskee
CJM- correct me if wrong, but Im pretty sure a lot of these companies are using the CDI box off the 250f dirtbike? I just tried searching it and can't find the info now. Thats why people say with the whitebrothers if u have trouble starting it use the stock box and once the bike is heated up then switch it over.

I think they use a xr250 cdi.

If you look, 450r, xr, crf, atc's and even scooters use the same type of cdi with the same type of wire harness.

They all use different timing curves and have different limiters, I actually tried one off a 2 stroke scooter once and it worked good up to 3/4 throttle with a nice increase in timing but after 3/4 throttle it was over timed and lost its arse.

With the white bros cdi, I never had any problems starting it, but after my valves and cam with my custom valve gapping, I cant even start the atv with a stock cdi.

White bros is best IMO.

Also if you have a timing key, a aftermarket cdi might not have the right timing for your atv to run properly.

[Jayskee]

Now I think about it.. I think you're right on the XR. I've only used TC racing box. Never had any problems. once again its probably rebadged, but he would never tell us.

[CJM]

Yes it is an XR250 box alot of the time. The white bros cdi isnt a rebadged xr250 tho, however I am sure the procom one I have is by the way it revs.

I went back to the stock CDI, the white bros worked great but caused me to rev out WAY to easy. I could max out 2nd gear like crazy and 3rd was too low most of the time. Most of the power came in the upper rpm band as well. Switched back to stock and although its different I like it better.

[atvrider13]

Originally posted by Rohr397
Yeah they really focus on the Unicam high performance engines. I'm sure a phone call would clear up any questions though.

As for the tensioner that's what I figured, seems like something you would install if you were going to rebuild the engine after every race. Again I think they threw it out there for 400ex's but it's really meant for one of their completely built engines.

Boneless since you've got a 450r definitey check out their stuff for that. The carb work is supposed to be amazing and there's lots more too.

***I'm not sponsored by them I just really have liked their products on the Crf250 and 450 and not a lot of quad riders know about them. Thought Id spread the word. I have seen the stock tensioners fail more times than i can remember, and wreck alot of expensive parts. I made a manual tensioner for my own quad . It sure is a good piece of mind knowing that the tensioner will not fail now.

[Otis.Leo]

I have the Dynatek and read up on it a little bit.. i would totally love to have way more out of the hole in second gear... i just need to read up and figure out how to program it.. i am all trails and need the pull out of the corners.. however the top speed has been pretty sweet!! :D

[JOHNDOE83]

Originally posted by Otis.Leo
I have the Dynatek and read up on it a little bit.. i would totally love to have way more out of the hole in second gear... i just need to read up and figure out how to program it.. i am all trails and need the pull out of the corners.. however the top speed has been pretty sweet!! :D

Is the one you have the same one that has rpm activators for NOS, shift light's and air shifter's?

If you get the program to make custom curve's, I hear that its hard to get the hang of it, but once you pin point what's doing what it become's a whole new animal...:cool:

[Otis.Leo]

Originally posted by JOHNDOE83
Is the one you have the same one that has rpm activators for NOS, shift light's and air shifter's?

If you get the program to make custom curve's, I hear that its hard to get the hang of it, but once you pin point what's doing what it become's a whole new animal...:cool:


its the 4th or 5th pic down.. i honestly dont know exactly what it is.

[CJM]

Just a small update:

I used the white bros cdi again. I can confirm it gives the quad a "more balls to the walls" feel. Again tho, as I noted before it seems to change the shift points and gives you more power in the upper rpm range. 1st and 2nd seemed shorter for some reason especially.