Help on souping up a ytm225dx

[rocketman123]

Hello everybody I am new here on this site and i have to say this place is the most informative and helpful 3 wheeler site in the internet! Thanks to all!

I have a 198? YTM225DX Shaft drive that i am working on that my dad bought about 6 yrs ago for 600 bucks. I will post pics later lol when i remember. So far I have put a DG Reverse Core Megaphone exhaust on it and it quickened way up! Especially since the stock exhaust was basically destroyed and blocking the flow. I have also converted everything to full synthetic oil and 10% Lucas stabilizer. I plan on taking the airbox off and putting a K&N cone filter on it and putting a Rick's Hotshot ignition coil on.

When i put the exhaust on, i noticed a hesitation started when u mash the gas. if you bring it up in rpm before you nail it it accelerates alright so im thinking that it's running lean?? it doesnt have an incredible throttle response but it is faster on the top end because of the exhaust. When i took the airfilter out of the airbox, I ran it and it wouldnt even rev up, just die when u punched it. Any suggestions?

If I do need to rejet it, would I be able to put a bigger carb on it like a 34mm Khein or Mikuni carb or would that be too big for what my upgrades require? do you think i could upjet my stock carb enough to compensate the increase airflow?

I have heard of the plug chop for evaluating lean/rich conditions but not sure really how to do it. Any suggestions??

Also under hard acceleration in 5th gear, it drops out of gear to 4th every once in a while. What should i do to fix it??


Sorry for so many questions and so long of post but i like to ask questions and i got a lot of them lol!!! Thanks for helpin me out!

[rocketman123]

anybody??

[2quicktecate]

leave it alone and buy a 250R

[Frankencelery]

Welcome to the board! I just bought one of those too. I'm sorry I can't help you with those questions, some of that is pretty advanced stuff. Once you start changing to aftermarket performance parts, you may end up with a lot of trial and error to get things right. However, you did give me an idea....mine has Cobra exhaust on it, and at the top end it sputters like it's out of gas. Maybe I need rejetting too. Not that I'll ever do it. Too many other projects.

I would bet there's only a handful of people here on the board who can answer all those questions, and there are so many variables that most people probably went "Uh...don't have time for that one!" Try asking just one or two questions, and you might get more answers.

[SYKO]

that size carb your wanting is WAY to big for that bike... but im not a 4 poke fan so im going to stay away... my .02

[trizilla]

a 10.25/1 piston will help. you can also get an aftermarket cam it should help all over. when i had mine i often thought of tearing the carb from my ladys beartracker and puting it on. i dont know the size but it was definetly bigger. i also searched once and remember reading that a klr 250 cdi box could be used with a bigger cam. i dont know anything other than that about the cdi upgrade.

[Vealmonkey]

You have to search for performance parts. I'm not sure it the 200 parts are compatable with the 225, but I've seem some 200 performance stuff. I sold a Pro Tec pipe for the 200 within the last 8 months or so, but I've seen double wound valve springs, hd clutch springs, a cam, bleed kits for the front forks and a coupld of goofy parts. I don't know much on the yamaha 4 strokes, so I didn't touch any of these parts. If you can find what switches back and forth between the 2 trikes, if anything, you would have a leg up on most people here. Try ebay, there has been lots of ytm200 parts lately, maybe they will switch over?

[rocketman123]

sweet yeah i wont ask so many questions in one post next time. i understand what u mean.

yeah i wasnt sure if the carb would be too big. stock carb size is 24mm. Keihin makes a 28mm carb. would that be too big??

yeah i saw web cams makes 3 cams for it i think i will get one eventually along with the 10.25 piston. so i will need a different cdi for a bigger cam?

yeah i will have to check out whether or not 200 stuff wil interchange.

[trizilla]

you dont have to do the cdi to install a bigger cam. there are also a couple places to get cams. not sure how much stuff will go from the 200 to the 225 but, i dont think the old 1 piece pipes will work from a 200 to the 225.

[rocketman123]

oh cool yeah i know about web cams but are there more?