Thoughts on high performance cdi box for ytm 225

[TracySeats]

i was just looking on ebay and stumbled across this on ebay. A brand new high performance cdi box for ytm 225. So i started looking online and found a website that Carry it and here is what info they had on it and the website. url if you want to look it up too you may have to copy it and paste it in your search box.

https://www.rmstator.com/en_ww/products/high-performance-cdi-box-yfm-200-moto-4-ytm-225-tri-moto-1983-1989.

Brand new high performance CDI box
* Our part is a Plug-and-play unit, direct fit, and easy to install.
* Enhanced timing curve, increased rev limiter (approximately 1000 rpm)
* Higher grade of electronic components.
* The Quality exceeds the OEM equipment
* All products shipped are tested
* One year limited warranty

I was woundering if this is to good to be true or if it would increase the rpms.
I just finish building one of my 225 dx and used a 250 bear tracker cylinder, head, stage 3 hot.cam and there titanium valve spings ext. from web cams high compression piston (40 over piston for ytm 225) full dg exhaust , and ebc clutch kit. The head was ported and polished. even though all this did give me some more noticeable power it didnt really gain much top end. stock it ran 57 at tops and now runs 67 with all this done. if this cdi actually works like they say it will it would be a great add on to my bike to really be able to see what the cam can do.

[ps2fixer]

Since the engine sounds to be built to handle the higher RPM, it might be a benefit for you. Generally the factory CDI's limit the RPM to a safe value for reliability.

Quick example I know of is the 1UZ from a toyota lexus, factory rev limiter is around 6500rpm for the V8, but a header and an aftermarket computer can push the engine to 9k, but it isn't advised to hold it at 9k long since it was designed with 6500rpm limit in mind.

Pretty much what I'm getting at, unless you're looking to race your bike, I wouldn't bother replacing the CDI unless yours failed. $200+ seems like quite a bit for an aftermarket one, a lot of times you can do some research and find a cdi for a newer machine that has a bit quicker spark advance curve and possibly higher rpm limiter.

I'm assuming the machine used to top out at 57mph, and now it is 67mph, which really is a large gain if the gearing was kept the same. If you need to go faster for whatever reason, gear it up more, bottom end will be weaker, but the larger displacement and hotter cam should be able to keep up with a 5-10% gearing increase. Another thing to keep in mind is what is limiting the speed, I'm purely guessing the engine revs out and is limited by the rev limiter, and not areo drag (engine not powerful enough to go faster).

Another thing to point out that I didn't see in the list, since there are some pretty major changes on the engine, did you do anything with the carb? Bare min it needs to be rejetted richer, but a larger carb would be ideal such as from a 250 or 300cc machine.

[Yamawheeler]

Carb swap is a good idea or larger main jet. I run. 115 in my mikuni vm22 on my ytm 200 that I built for the mud.
What is your compression with the bear tracker head on it?
And the manifold for the carb can be honed out to be smoother and to fit the size of the intake port.
Changing tires helps out as well
Tri-z front end.
Raptor rim and tires. On the rear. (Need hub swap.)

[Ghostv2]

I'm assuming the machine used to top out at 57mph, and now it is 67mph, which really is a large gain if the gearing was kept the same. If you need to go faster for whatever reason, gear it up more, bottom end will be weaker, but the larger displacement and hotter cam should be able to keep up with a 5-10% gearing increase.

It's shaft drive. Aside from changing tires, there's not much you can do.

[TracySeats]

compression is 141. compression ratio is 10.25 to 1carb is jeted to run richer both Main Jet and pilot jet have been changed. it bounces off the rev limiter I don't do a whole lot of drag racing really. i just like to go fast i have 15 Acres of flat land that i ride on. only Built the bike to build one up to see what it could do. I just wanted to build one four stroke before I moved on to the two stroke three wheelers. and like Ghostv2 said its shaft not alot you can do there. even though the Timberwolf 250 or a bear tracker 250 has a different ring gear size compared to the 225 DX or DR. by a few less or a few more i wouldn't know which way you would need to go that could gain by staying 22/11/8 tires or 22/11/9 and if it will line up in the 225 rear id have to get one off ebay and test that but it may be a loss cause in that department. i may try the manifold hone but i dont want to go to much with it as ive herd they tend to break . it is alot more peppier than all my stock ones gets up to speed quicker and it picks the front end up through all five gears at ease so i am trying to see what i can do on that part if i did a tri z front end id want to scratch the rear out at least 4 to 6 inches ive seen i few on here but not enough info how they did it so ill have to figure that part out

[TracySeats]

It wasn't a cheap build by any means. it did cost me around 1600.00 to build this so far.

[ps2fixer]

I don't know the Yamaha models that great, but generally shaft drive Hondas are naturally low geared because they were designed to do work. Sounds like you got exactly what you should expect out of the machine really, great running, picks up well, wheelie in all 5 gears. Seems like a go getter ripping machine. My two 350x's only wheelie upto 4th gear, and 5th I can get a little hop out of and they are 6 speeds with probably 60-65mph top speed (never clocked it or anything).

If you want more speed and don't care about the bottom end grunt, get larger tires on the same rims. Lighter is better for speed wise. Since you're on 22's atm, going to 25 would be a large jump, so maybe 24's for around 8% increase in gearing if I did the math right. 67mph + 8% gain would be around 72mph at the same RPM if the engine has enough power to rev out. Shouldn't be much more reason to go any faster for general riding. If you want more speed, then it does sound like you need a 2 stroke 3 wheeler, but most people don't gear them up for higher top ends really. I have seen the 250r quoted at 72mph top speed and the 350x 65mph, lots of debate about it on the forum, but either machine can go faster with the right gearing on a purely factory engine.


Personally I wish Honda would have made a shaft drive version of the 350x (besides the trx350d 4x4), love how the power delivery is, but chains can be a pain some times. I just prefer shaft drive I guess lol.

[TracySeats]

i thank you for the info on that. i wish yamaha made a 350 three wheeler to match the 350x but that might be a nice project to build to be honest. take a tri z and put a good warrior motor on it and set it up to be the 350x competition i may do that build but ill have to have permission first from the wife lol. iv owned a few four wheeler but didn't like how they handle so i started collecting my favorite three wheelers right no i own 2 84dx 1 85 dx 1 85 dr my future add ons to my collections will be 2 86 tri zs one 2 stoke and one changed to 4 stroke a 86 250r 86 350x 86 t3 after those i may start other various models

[Yamawheeler]

Timber wolf swing arm mod ads about 3" in length. I know a guy who has one on his dx. Are you on the Yamaha YTM three wheeler group page on Facebook?

[ps2fixer]

If you need warrior parts, I have an 87. The machine was just trashed and was from a larger city near me. They claimed the engine ran but the wiring was hacked up so bad I never had a chance to really try. I removed the engine and put it in a shed. It turns over but something didn't seem right with it, I think it sounded like a crank bearing was bad or something was dragging internally.

I had a 85 tri-z that was converted to a quad, it was about the same speed as the 99 350 warrior I have, but the Z had a fuel delivery issue (float bowl would run out of fuel on hard riding), and the quad front end is quite heavy. I ended up parting it out, not much left, but if you end up getting one I might have parts for it.

I'm right with you on not liking how quads handle, first 3 wheeler I owned was a 200es big red... not exactly a fast machine or great handling, but I liked it so much more than the 99 warrior that the warrior sat long enough to developed carb problems.... my dad bought it new and I'm the 2nd owner! I have some plans for it but will be in time.

[TracySeats]

no not yet but i will be now lol. ill look that up.

[TracySeats]

yeah i might be interested in the motor. what are you asking out of it? my first three wheeler was a 125m when i was 8 years old then i had a 200s 200es 200x and ytm 200 shaft owned 2 of them they were alright not very fast except the 200x it ran pretty good but plastic was all broke sold them all when i bought my first 4 wheeler then got rid of them and got all these 225dx's and dr id have to say my dx would problem give the 200x that i owned a run for its money when it was stock. the only 4 wheeler i own is the 250ex my wife rides she ride a little to hard for me to put her on a three wheeler for the first time so i got her that. im hoping i will have my built dx rear done up by the time trike fest gets here other wise ill take my other one that's just piped out there. it will be my first time out there and hope i see lots of cool trikes.

[ps2fixer]

I have been there the last two years, and there is always something interesting in the groups of 3 wheelers =). Threw up a few photos between TF2014 and TF2015. The rare/uncommon trikes and custom built trikes are atleast always a nice site to see. Fair share of atc70's running around, probably half with Lifan engines.

I can't guarantee anything about the engine, but since you'll be at trike fest I could bring it along with me there. My original impulse was to part the engine out since the stator and such goes for a bit. From memory the chain side of the engine was in good shape yet. I'd like to get around $200 for the engine, but I suspect you need the carb too, maybe $250? Carb would include cable, thumb throttle etc. I can get some photos to give ya an idea how it looks. I can ship it as well, probably end up running close to $100 though, but I pack engines very well, not easy to unpack though lol.

[YamaBoss]

Let's see some pictures of this beast.

[TracySeats]

ill take some pics when i get back to Indiana im out of state right now lol but as soon as i can i will post a pic of it. i came wait for trike fest either

[TracySeats]

here is one before i did the motor its the blue one beside my yellow dr 229837229838

[TracySeats]

i will be replacing the front fender when i find a nice one so it will look as nice as the rest of the plastic its never been painted and its how i want it to stay the front fender has a crack down the middle of it that's how it was when i got it. after putting these on here it actually adds my collection that i have so far the other two are in my profile ill have to take better pics with the new phone when it comes in. they don't set out side in the weather i have them put up in the barn i had to move them out of the garage that day i took those pics . i have 1 1984 black dx 1 1984 blue dx 1 1985 blue dx 1 1985 yellow dr

[TracySeats]

i would be interested in the motor for 250. but ill probably have to get it from you after trke Fest. a little on the tight side on money right now and may be moving later this year

[rsmitty1000]

did you take some pics in the end. let's have a look:pics: