I know thins isn't the Yamaha forum, I tried them and the site is down for a couple of days. Anyway my wife's bike is so hard to start that I almost pulled out my hair the other day. The Yamaha XT 225 is known for being cold blooded and so I was prepared to find a fix even as I signed the papers at the dealership. I did the air/fuel screw mod, and now I would like to jet the bike. The problem is that I called the dealership and they said that they couldn't find a kit for this bike. Well I find that hard to believe since the mechanic that jetted my bike told me that jetting it would fix the cold start. In fact he told me that while they couldn't do anything to the bike as a new machine, once you walk off the lot and come back then they will do whatever you want to make it more user friendly. So does anyone know of a few places that I could check out to see about getting a jet kit? The guy at the parts place told me that from the factory the XT 225 comes with a 40 or a 45 main, man that seems big to have fuel issues. In fact the only way I could get both of the 225's started the other day was to pull the air box lid off. The air cleaners are both really clean and the temp was around 45. ???

 

My brother has an XT225 and I had a TTR225 (same engine), I performed the following mods to both bikes and the hard starting issue was resolved as well as improved performance:

• Replaced stock air filter with Uni aftermarket filter
• Changed pilot jet from 40 to 42.5
• Reset fuel screw (2.5 turns out, I can give detailed pictures for jetting)
• Changed main jet from 130 to 132
• Removed air box snorkel

Finding the jets was a pain. I got the main from ThumperTalk and the pilot from a local dealer. I may be able to dig up a Yamaha part number.

 

Sweet Thanks Ryan, I might try the snorkel mod, and if you have any part numbers that would be great. Running the air/fuel screw out 2.5 turns did help, but I think it needs a little more persuasion.

 

On my 1992 XT225(Serow), the only way it would start when it has been sitting for a while is to push the choke **** full in and full out very rapidly while pushing the starter. Don't know why it works but it worked everytime. When the bike sits for a loooong time, it always needs a wiff of starter fluid.

Hands down, the worst cold starting bike I have ever owned. When warm, it starts instantaneously.

 

Glad to help deej!

I found the numbers!

Pilot 42.5: Mikuni part no. N151.067 you can get it here

Main 132: Mikuni part no. N100.604 which you can also get here

 

I forgot to mention that I also performed a sweet BBR exhaust mod:



and removed this screen:



with this result:

Yehaw!!!

 

Thanks Ryan, you're the bomb!! What does the exhaust mod do for you? I mean do you have to do it in connection to the jets? Also I heard that taking the screen out of an air box is dangerous and can lead to a backfire....fire. Any thoughts? Also I wonder if the 225 forums show how to do the exhaust mod? Thanks again.

 

Oh I forgot to add we are in the middles of Forest Service areas, and I want to keep the exhaust on her bike as legal as possible.

 

Before I order the two jets, I have one final question for you or anyone who might know. Can I just add these jets without changing anything else on the carb like the slide or drilling anything?

 

More like riding a bomb (potentially)!

No, you don’t need to do the exhaust. I think it cost me about $48 so I figured why not. I got the parts at the same store that has the jets. There are extensive directions on another site; I can get them for you if you can’t find them.

As far as the screen goes, I ran the thing pretty hard for two seasons without a fire, but I’ve since sold the bike. I hope the new owner has the same luck! The exhaust was still pretty quite, not like the thumpers you can hear miles away. It merely gave it a very subdued growl and opened it up a little. I have a video of me on the bike with the exhaust mod, just not sure how to post it? You can also see the spark arrester in the picture so it’s legal and I’m sure well below decibel limits.

And yes, you can add the jets without changing the carb, that’s what myself and many others have done. I hate to plug another site (ThumperTalk), but the info there is very informative for the TTR225 which is the same engine. Even without the exhaust, the jetting change helps. Like every other darn bike, the bike is very lean from the factory. I don’t even know if the slide on that carb can be drilled like our 250S…

Good luck!