225dx won't run right

[motoman011]

I purchased a 225dx, and at first it would not start, I removed the carb and cleaned it, it was real dirty from sitting in a barn. I started it today for the first time, it runs, but pops through the exhaust. I set the piolt jet at 1 1/2 turns out, and have adjusted it frorm one turn out, all the way to 3 turns out, either way it doesn't make much of a difference, still pops, does not idle well and the idle will not come down correctly, I have it close now but the coughing (popping) has not stopped. Any ideas would be great. Here's a picture, I believe it's all there. I'd like to keep it but if it's something major, it's gone. http://i438.photobucket.com/albums/qq110/motoman011/HPIM1240.jpg
http://i438.photobucket.com/albums/qq110/motoman011/th_HPIM1241.jpg (http://s438.photobucket.com/albums/qq110/motoman011/?action=view&current=HPIM1241.jpg)

[3podd]

Check the petcock for flow. and for correct spark. run down the diagnostic list of things to do.

[MudBug]

timing may be off a hair? mine was and my bike would backfire like crazy.

[motoman011]

Spark is great, fuel flow seems fine, steadly stream coming out the fuel line. Not sure about the timing, or how to check it or if it can be adjusted.

[motoman011]

Ignition timing is not adjustable in these engines according to the manual, but I know both marks line up inside the inspection hole

[MonroeMike]

Are you sure you got the pilot jet clean? (you can see light through it).

[motoman011]

air blows through the pilot jet, but no I could not see light, I remember thinking that, would this cause a backfire? I'd really like to keep and restore this thing.

[motoman011]

Can I still get a pilot jet for it, I believe the manual says it's a 20, I guess that would explain the hanging idle, and maybe the backfire due to the fact it's running lean.

[MonroeMike]

The hole is so tiny through that jet (it tapers).

I had to burn the paper off a garbage bag tie and used the wire from it to carefully clean it out (lot of soaking in carb cleaner).

On a side note, make sure you clean the (tiny) starter jet (it's in the flange of the bowl, not the carb) #9.

http://www.xtremeusa.com/fiche_section_detail.asp?section=2554&category=ATVs&make=YAMAHA&year=1984&fveh=69

I would soak it with PB Blaster first, I'm sure it's corroded in there and make sure you have a good quality screwdriver that fits perfect, or you will strip it.

[unclejemima]

On a side note, make sure you clean the (tiny) starter jet (it's in the flange of the bowl, not the carb)
I would soak it with PB Blaster first, I'm sure it's corroded in there and make sure you have a good quality screwdriver that fits perfect, or you will strip it.

Good post MonroeMike.

As for the starter jet, is this unique to Yamaha carbs? Seems its in a stupid spot and real tough to get out.
Do you know if it is a flat head or allen type bolt?

Of the two Yamaha carbs I took apart, the one had the start jet intact and if I recall it was a allen head bolt, but the other had the starter jet completely removed. Both machines started up just fine.

Any idea how this jet works and what it does?

[MonroeMike]

I've only seen it in the flanged YTM carbs and they were slotted, not allen.

[motoman011]

It's slotted, I got mine out tonight and cleaned it up, I also tried the wire trick, GREAT! I now have a clean hole in the pilot jet and have went back through the entire thing again. I believe I have everything. I won't be able to try it out til Sunday, hopefully it works, I'm still concerned about the popping, but a lean mixture or messed carb can cause that. Thanks to all who have helped me!

[MonroeMike]

Hope it runs better.

In hindsight, I should have suggested you check the tube that goes down into the starter jet hole, that clogs easy too.

If you blow compressed air into the right hand hole, (outlet end of carb, side opposite of the idle screw) and hold your finger over the choke plunger hole, air should come out that tube.