225 dx questions

[85burbanator]

Traded the kids alt 50 for a 225 dx. I'm slowly rebuilding another one i dug out of a.buddies field years ago but this one runs haha. It leaked fuel like crazy at the guys house and has a thumb throttle vs the twist on my 100 percent original one. Take the carb out and its huge, found out because I was just going to swap carbs. Not sure where to look for marking interpretations but it's a mikuni round slide, had to bend the little tab for the float needle. He said it floods out but I've ran a whole tank through it with no issues. I did notice some cracks around the flag from the carb to motor but I'm not sure the carb size (no mics) to get a new one. Also, at higher rpms it cuts out big time and takes a minute for the the clutch to engage at the low end. Very hard to predict wheelies. I parked it since the motor is starting to "run away" which I believe is due to the carb flange letting un metered air in.

It's a mikuni kogyo and has wz 31 stamped into a little square with the w above the z and the 3 above the 1. Any idea what it is or how it should be jetted? I wrote the jet sizes down but it's on the bench in the garage.

The bike looks to have been flipped as the light control thing is broken and the brake lever on that side has been replaced.

[DohcBikes]

Post carb pics.

Your carb should be a vm24. Main 112.5, pilot 20.

Sounds like you might be running lean, but I can't say for sure until you've checked for air leaks. Having a positive I.D. on the carb model will help with diagnosis.

Check for air leaks by spraying starting fluid around the intake to engine area and the carb to intake flange at idle. If it revs or dies you have an air leak.

[85burbanator]

http://i37.photobucket.com/albums/e74/85burbanator/Mobile%20Uploads/20160730_132012.jpg (http://s37.photobucket.com/user/85burbanator/media/Mobile%20Uploads/20160730_132012.jpg.html)

[85burbanator]

http://i37.photobucket.com/albums/e74/85burbanator/Mobile%20Uploads/20160730_145611_1.jpg (http://s37.photobucket.com/user/85burbanator/media/Mobile%20Uploads/20160730_145611_1.jpg.html)

[85burbanator]

One jet was .25 and the other was .280. Not sure which one was which. I can take the carb apart again I guess. The flange has many dry rot type cracks in it, I'm sure it's leaking, I'll check though

[85burbanator]

Pilot was 25 and main is 280

[DohcBikes]

I cant be sure from that one pic exactly which model your carb is, but it's 100% surely not a stock DX carb. You can get quality replacement carbs from Wincycle on ebay if you chose to go that route.

Definitely would like to see more carb pics. The jetting you mentioned is usually meant for 2 stroke stuff. Might be fun to play around tuning it, but at some point it becomes smarter to just get the right carb.

[DohcBikes]

Yea that's way too rich for this engine or any other small four stroke. Chances are the carb venturi is too big too. There should be some numbers somewhere else on the carb. With a couple more pics, from farther away, we can i.d. it.

[85burbanator]

I couldn't find an other numbers. I did find a vm manual on mikuni site, I'll have to borrow some micrometers from work and match up dimensions.

Do you think that could effect the throttle response through the clutch? Fingers crossed that that isn't toast haha

[85burbanator]

I'll pull the carb after work tomorrow. Any idea where the numbers could be hidden?

[DohcBikes]

It might be stamped on the body just above the bowl gasket. I will also say that it does probably have air leaks between the carb and the motor. What can happen with jetting so rich is that when it's not pulling the extra air it cuts out, and when it pulls in extra air it can make an overly rich engine race. Either way, the carb and its tuning are not correct for your application.

Is the intake a stock 29U intake?

Have you attempted a clutch adjustment?

[85burbanator]

It's a very short flange, maybe an inch long or so. The stock one is significantly longer, but narrower. It runs pretty ok for the most part, which is odd. Starts right up no mater what, idles fine in gear but pretty high in neutral.

Started reading up on clutch adjustment, I have a Clymer that covers a few models so I have to skim. Also have a copy for the 225 burned on a disc someplace.

[DohcBikes]

Basic clutch adjustment is pretty simple. Loosen the locknut on the adjuster screw, turn the adjuster in till it stops, then very slightly back it off.

Runs ok, well alright. Not to be picky but so far i hear it idles high in neutral, cuts out at high rpm and runs away. Kinda sorta sounds to me like it runs like crap.:) Those are all things that can happen if you have the wrong carb.

But I hear ya, it isn't surprising to hear that the bike runs ok. Carbs and four strokes are pretty well apt to run if you spray air and fuel in there. It's all about how well you want it to run.

[85burbanator]

I'll give the adjustment a try. It's hit or miss and didn't start the idle issues until the last time I rode it. The cutting out at top end has been since my first ride. Ill pull the carb and get better pictures and measure it up. I'll also put my stock one on to try it out.

[85burbanator]

Found some mics and it looks like it's a vm28-49. Put it all together and ripped it around and it had way better throttle response seemed better even though I did nothing. I'll upload some pictures after dinner

[85burbanator]

http://i37.photobucket.com/albums/e74/85burbanator/Mobile%20Uploads/20160808_175012.jpg (http://s37.photobucket.com/user/85burbanator/media/Mobile%20Uploads/20160808_175012.jpg.html)

[85burbanator]

http://i37.photobucket.com/albums/e74/85burbanator/Mobile%20Uploads/20160808_172458.jpg (http://s37.photobucket.com/user/85burbanator/media/Mobile%20Uploads/20160808_172458.jpg.html)

[85burbanator]

Took a video as well but having a hard time getting it off the phone

[czac]

http://www.partzilla.com/parts/search/Yamaha/ATV/1985/TRI-MOTO+-+YTM225DXN/CARBURETOR/parts.html#uloc11

link to parts diagram of carb... by the way, that carb of yours looks nothing like the one on my 85 DXN...

[czac]

Heres a free downloadable service manual for your trike...

http://www.oscarmayer.net/atc/manuals/

[czac]

http://i37.photobucket.com/albums/e74/85burbanator/Mobile%20Uploads/20160808_172458.jpg (http://s37.photobucket.com/user/85burbanator/media/Mobile%20Uploads/20160808_172458.jpg.html)

what year is that trike??

that whole setup looks alot different than both my 85 DXN and 84 DXL that flange, carb and intake look like they may have been added on by someone.. the carb its self looks HUGE! lol

[czac]

here you go...

https://photos.smugmug.com/Other/Yamaha-225-DXN/i-jdLW5Xv/0/X2/carbs-X2.jpg

[85burbanator]

Not sure, haha. Haven't looked. It's is, someone down the line added it and used some flimsy duct stuff to connect to the air box.

[85burbanator]

Not sure, haven't looked yet. The carb is huge. It hits at the top. They used some flimsy ducting to run to the air box. May have totry and boost performance on this one haha

[85burbanator]

Rode it with this carb for a bit until it started idle high and wanting to take off. The carb mount was trashed. Pulled the stock carb, mount and choke off my other 225dx and put on this one. Still idles high but I found the throttle cable may be a bit short or not routed correctlyl, I can wiggle it and the rpms fluctuate. Power delivery was better and only bogged once. Also changed the motorcycle brake lever for a stock one so the front brake lever for the rear brakes works. No more 12 o'clock wheelies with me on my back haha. I suck at wheelies haha.

Has a spark issue, swapped coils and it works for now. Fried something in the starter circuit with a charger, oops. May have a clutch issue since it's getting hard to shift and now neutral is getting tough to get into, really have to cram it into gear.

[DohcBikes]

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=maintenance

[85burbanator]

It never ends, runs better than when I got it though. It didn't live an easy life that's for sure. I've already put it to work pulling a yard rake and drag for the driveway

[czac]

nice. i got mine back up and running again... now i need to get the other one i picked up, running. Had to find a cheaper priced carb for it. finally found one from a Wolverine 250 on Ebay for 25 bucks. just need to take it apart and clean it and put in my 225's jets. then maybe ill get it to run!

[muthey]

that carb and intake is off of a yamaha dirt bike more than likely