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View Full Version : 1985 Yamaha 225DX runs like a dog Help



teddcmiller
04-03-2025, 10:32 PM
Long story short, I finally got my hands on the three-wheeler I've been chasing from almost 20 years. I'm an amateur mechanic, so I'll try my best to describe the problem.

When I got it, my father-in-law said that it ran great but it wasn't accelerating as fast as it used to/should. He tried to re-build the carb, and installed an in-line fuel filter because he suspected it was the gas.

When I got it home, I removed the in-line filter and replaced the gas line and started using a small amount of Seafoam in the gas. It started to run better, I got my hands on an old Clymer manual where I read about adjusting the circlip on the throttle needle. I pulled the needle and found out that the clip was set to the 1st lean setting above what would be "neutral". I moved the clip down to the center setting, and it is accelerating/running slightly better.

However, when riding for long periods of time it starts to bog down really bad you can actually feel the machine lurch and it occasionally backfires. During acceleration, it feels like I'm trying to pull a loaded wagon behind me.

Is the throttle needle setting still set to lean? Or do i need to bite the bullet and re-build the carb? Or do i need to take a look at the timing? Or is it something more serious?

Thanks in advance.

Footy
04-04-2025, 10:14 AM
Sounds like a possible float level issue. The manual should explain how to set the float level.
Could be needing a new float valve as well (needle and seat set).

Also could be a plugged up exhaust system but i am leaning toward float level.

ATC King
04-04-2025, 11:21 AM
Anytime a trike has sat for a while and there's issues with it running, always check the air intake patch. Primarily on the trikes that route it through the frame. All kinds of critters can nest in there and plug it up. Just blowing compressed air through isn't enough, something flexible but solid needs ran through, to bust up any solid nests, then follow with air.

I've ran across this several times, and on my YTM200K, which I've posted a picture somewhere on here.

ATC King
04-04-2025, 11:36 AM
Found them. There were a couple larger dirt dauber nest in the frame, up near the opening in the front.

https://www.3wheelerworld.com/attachment.php?attachmentid=264024&d=1597763616
https://www.3wheelerworld.com/attachment.php?attachmentid=264025&d=1597763626
https://www.3wheelerworld.com/attachment.php?attachmentid=264026&d=1597763638