Yamaha TTR 225 no power under load

[happysaws]

Super off topic here, but here goes.

I got a 1999 Yamaha TTR225 a few months back, and I cannot get it to have power under load. So far, I've rebuilt the carb, replaced the fuel shut off valve, installed an E3 plug, and replaced the battery. I've even tried oversized carb jets, but those didn't help either.

It starts up, idles and revs up fine in neutral, but when I put a load on it, it has no power whatsoever. For example, on a straight away, if I bump it into 4th gear and give it full throttle, it'll just sit at the same RPM and not gain any speed at all.

I'd like to try to avoid paying a repair shop if at all possible.

Thanks for any help or advice!

 

[cuinrearview]

Is there some kind of screen in the tank? Sounds like a fuel obstruction to me. You didn't mention a filter.

 

[happysaws]

The fuel shut off valve has filters on it, and I replaced the valve because the handle was broken off the old one, so it does have new fuel filters...

 

[cuinrearview]

Blow some compressed air back through the valve and line into the tank.

 

[happysaws]

Got it running (said this before, knock on wood), kept switching carb parts until it had power. Now it doesn't idle very well, but at least it runs for now LOL

 

[cuinrearview]

Is a rebuilt or new carb that cost prohibitive?

 

[happysaws]

Well, maybe a little.
I did rebuild the carb, as mentioned in my original post. It really started acting up after the carb rebuild, so I put some of the old parts back into the carb, specifically the jets. With the old, original jets reinstalled in the carb, along with a new needle and seat, it runs with plenty of power... Just doesn't idle all that well. If I get the time and/or ambition, I may reinstall the oversize pilot jet to see if that will help with the idle issue.

 

[Bwildered]

Well, maybe a little.
I did rebuild the carb, as mentioned in my original post. It really started acting up after the carb rebuild, so I put some of the old parts back into the carb, specifically the jets. With the old, original jets reinstalled in the carb, along with a new needle and seat, it runs with plenty of power... Just doesn't idle all that well. If I get the time and/or ambition, I may reinstall the oversize pilot jet to see if that will help with the idle issue.

Check the valve timing .

 

[s sidewall]

Are you running it without the air filter?

Steve

 

[happysaws]

Are you running it without the air filter?

Steve

Ya, why?

 

[s sidewall]

We had a problem trying to fix a carb problem on a Polaris, had no power after fixing carb. We put the air filter back on and fix the problem. Original problem was the needle had worn in half at the retainer clip.

Steve

 

[s sidewall]

Brother had a TTR225, fun bike on the woods trail, but I like my son inlaw's Kawasaki KDX 220R a little bit better, a lot more power and zip when you want it, hard to bet that 2stroke. Brother also had a Yamaha YZ 250, that was too much power.
Had to edit.
Steve

 

[1Alpha1]

If there is a baffle or a spark arrestor in the muffler, pull it out and inspect it. It may be all plugged up.

I'm not familiar with the TTR225, so it's just a thought.

 

[s sidewall]

I thought of that also but, don't remember those having one, spark resistor that is.

Steve

 

[1Alpha1]

I thought of that also but, don't remember those having one, spark resistor that is.

Steve

If it didn't, I'd be surprised. It will have a baffle of some kind though.

 

[s sidewall]

I know my brothers bike didn't have a spark resistor in his, unless it's was welded around the baffle, that part was unremoveable on his.

Steve

 

[s sidewall]

How's the bike coming along?

Steve

 

[1Alpha1]

I forget what year it was, but back then, all dual-purpose m/c's imported into the USA had to have a USFA spark arrestor.

Mid 1970's maybe?

 

[s sidewall]

Bro's was a 2014, YZ 250 ws also a 2014. Like I said, don't remember seeing one on his TTR.

Steve

 

[1Alpha1]

A mystery wrapped inside an enigma perhaps?

I did find this exhaust parts schematic. If you look at part #8, you'll see some "fins" on the muffler insert. Those act as a spark arrestor.
You can - / + to enlarge the screen. If the holes in that insert are plugged, the bike will not run properly, if at all.

https://www.yamahapartspro.com/oemparts/a/yam/50044ae9f8700209bc7909eb/exhaust