I can prolly figure this three turn thing out but was looking for a pic of the carb showing the location of the tamper plug that needs to be drilled out on the XT225. New to the site and still trying to get used to the search function on here. Is it basically in the same location as on the 250?

There are pictures around here somewhere. It's on the bottom part of the carb closest to the engine, between and slightly forward (towards engine) of the front two (of the 4) screws that hold the floatbowl on.

Do NOT confuse it with a close-by brass "dimple" that is visible in one of the holes.

Not all bikes have the anti-tamper plug...

Alexd

Here's one; not all carbs have the hose, which is partially obscuring the pilot jet adjustment needle (the anti-tamper plug has been removed) A small flat-blade screw driver is used to adjust it.

Alexd

Here's another; the plug was pre-drilled, as the owner will be inserting a screw to "grab" the brass and allow pulling the thing straight out.

When you do this, be sure to not drill in too far, which would gouge up the adjustment needle within.

Alexd

Great! Thanks for the pix

You're welcome.

You might want to take the opportunity to replace the 4 Philips-head screws that hold the float-bowl, with Allen-head types (which won't strip or deform). I forget the metric size (possibly M6) but 12mm or 16mm length is fine, in either black or stainless. Home Depot, Menards, and Lowes should have them.

Alexd
(P.S. Look into a fuel line filter such as the mini 1/4" Visufilter, for your next Mod)

One thing that will help on stripping phillips screws on Japanese bikes and other equipment would be to get a set of JIS (Japanese Industrial Standard) screw drivers. Japanese phillips are not the same as our phillips and that is why they strip so easily. I removed my bowl screws last week on my 2005 xt225 no problem. Just do an Amazon search for jis screwdriver. Regards, Tom

That's interesting to know! A while back I was removing "secondary throttle plates (butterflies)" on my Yamaha FZ-1, as part of a performance modification. The word was out that only a specific brand of #2 Philips screwdriver had the best chance of not stripping the screw heads...something we REALLY didn't want to happen on the bike. It was an American brand though...

By the way, we heated the heads with a 100W soldering iron prior to loosening...to soften the loctite glue that the factory used in original assembly.

Alexd

The American phillips drivers have a radius at the root of the four blades, the jis has no radius, goes down to a 90° corner. JIS works good on American screws, but the radius on the American driver keeps it from fully engaging the jis screws. I just ordered a set of long and short hex shank jis bits, $45 ouch. They will work well in my Ryobi battery powered impact driver. Regards, Tom

Mission accomplished. Running much better now. Also added an in-line filter. Still some spit/sputter in the higher gears and can only get it up to about 50mph but it seems to be getting a little bit better each time I ride it. Any tips what to look for next?

Post again, as a reminder. What has been done to your bike in the way of Mods, or is everything stock (or not known if someone previously had it)? That will help in figuring out the next steps.

(you now have the pilot jet adjustment screw out at 3 turns?)

Alexd

Sure. I picked up the bike non-running from the orig owner. First problem was a stuck neenle valve allowing no fuel into the float bowl. Fixed that and could get it to run only fully choked and even then not very well. Drained the old fuel and put a can if seafoam in the tank. Ran it till the seafoam got fully into the system and would not allow the bike to run any longer. Let it soak for 24 hours and drained the seafoam and replaced with new non-ethanol gas. Little to no improvement at this point. Pulled the carb and drilled the tamper plug out. Adjusted the pilot mix screw to three turns out. Also removed the pilot jet and ran a tip cleaner through it and gave it all another good spray with carb cleaner. Reassembled and started the bike. Now running much better, I took it for a short ride. Returned home to find the bike had warmed up nicely but the warm idle was now way too high. Exhaust pipe was glowing red hot when I got home. I lowered the idle and it now starts andidles well but still has a miss and poor power in higher gears. Also, the intake tube(or whatever it's called) between the carb and the jug looks badly cracked and probably needs to be replaced. Is this common?

Do you recall if you're running the stock main jet (and, is it clean)? (#125)

Did you check your float-heights to see if they were within specs, at any time?

Stock muffler or Z1 mod?

"Snorkel" is in place or removed?

Air-filter in place and clean?

We don't know yet if you're running rich or lean...but should know soon.

Cracks that are all the way through, on the carb-engine duct will cause the bike to run lean. Usually, they don't penetrate all the way though; you can test this by spraying something like WD-40 on the duct while the bike is running, and both listen for RPM changes and look for bubbling. Check all ring-clamps for leaks there too...

Alexd

Believe the jet is stock as are the intake snorkel and exhaust. Air filter is in place and clean. I did not check the float level- function only. Bike only has a little over 2000 miles on it and does not appear to have been messed with much.

I'll check the carb-engine duct(thanks) with some sort of spray as suggested. Clamps are tight.

Thanks again for all the help!

After you make the test with the carb to engine duct...and if there is no effect to the spraying...we can try another simple test with the air-filter cover (I'll explain later).

I'm assuming that the fully warmed-up idle is working reasonably well...steady RPM at a reasonable speed with your hand off the closed throttle. And, that the bike starts cold now with full choke, and choke MUST be pushed in as it warms within a few minutes...

Alexd

Warm rpm is great now. Cold start is easy now with full choke but it takes a looooong time to warm up enough to start to open the choke which I understand may be fairly normal for the XT.

If your test with the spray doesn't show any cracks that are all the way through, and no leaks at the hose clamps.

Then next, we want to check for overly rich:

Thoroughly warm up the bike. Re-test it; apparently it is showing that it will not do full revs in 4th or 5th gear.

Now, pull off the side cover and remove the 3 screws holding the air-box cover on (don't remove the air-cleaner)...after removing the air-box cover, put the side cover back on, and immediately while the engine is hot, do the same test again: Full throttle in 4th or 5th.
Does it rev higher with less stumbling, or act the same way or worse?

If the first result, we've proven it's too rich. If the second, it's not...and/or running lean.

Do all this with 100% throttle...you can also get up to 30 MPH in 6th, and open it fully up for 10 or so seconds from that point, as a similar test.

By the way, you do have a new spark-plug in it...right?

Alexd

Plug is a month old according to PO but I'll put a new one in tomorrow just to scratch that one off the list.

No RPM change with carb cleaner spray on the carb-engine duct so that much is good news. Did the air filter test with no real change in performance. Ran it first with the filter on and did the 30mph in 6th with a 10 second full throttle test. The bike only got to about 44mph on the first test with the filter. Repeated the test again with the filter removed and got to maybe 45 on the same stretch of road. Just for grins I did the test again with the filter replaced and got to 46 this time. Oh, all of this with a new plug as well.

The bike seems to be getting slightly better with each run. I'm kinda big for this thing at 6' and 295lbs but I thought it would do more than this. I'm guessing a valve check is next?

Wait...I said air-box COVER removed, not filter removed (leaving the air-filter in place). Was there a misunderstanding?

The air-box cover is held in place by 3 screws.

Alexd

Oops I sure screwed that up didn't I?

Guess I gotta do that again don't I! That will teach me to pay closer attention. Sorry

OK- finally repeated the test the RIGHT way this time. Warmed up the bike and did the 6th gear 30mph to 10 seconds full throttle test with the side cover on. Bike got to 46mph with the cover on. Repeated the test on the same stretch of road with the air box cover off and it did just a little better. Speed got up to 49mph this time and the bike did feel just a little better going through the gears. Still very low on power though and top speed was still only about 53mph.

What's next and thanks again!

As far as top speed goes...and with your test that didn't quite get to top speed...what happens? Does it "spit" or backfire, or any sharp noises (lean) or does it make a duller stumbling, blubbering noise (rich)?

I was hoping for a more radical change than what you experienced.

There is a science to reading the color of spark plugs, but just for the heck of it, pull it out and see if it's VERY white or dark brown.

If the bike starts well, and idles well when warm...probably your valves aren't too bad. Compression though is another thing.

Alexd

No sharp noises or backfiring. Just a bit of a miss from time to time. The plug I just removed looked quite good to me. Not wet and color was a chalky light brown color. I see no sign of oil burning or excessive lean condition.

I'll do a compression test tonight. The bike only shows 2600 miles so I should think that would not be the problem but... What should healthy compression be?

Is this a new problem? were you at one point getting more then 53mph top speed?

It's all on pg2 of this post but I bought the bike not running from the original owner. 53mph on flat ground is the best I have been able to do. As I said earlier, I am kinda big for this bike but thought it should do better than that. Maybe not? Is 6' 295# asking too much? (I really need to lose some weight...)

Im not sure, but it may be a bit much for the bike, being around 300 pounds, but then again it might not, my sister (125 pounds) and her husband (175 pounds) went on my xt250 for a spin, and it did fine with both of them on board.

Do you have anyone who is average weigh around you that could take it out for a good test ride? lets say around 180 pounds or so, that way if they ride it and it goes to about 70+mph (top speed) then you know there is nothing wrong with it, and if it still does the same thing (53mph top speed), then there is definately still a problem.

Thats the first thing i would do.

This is a weird problem to solve, because there could be several factors playing into the problem.

Weight alone shouln't affect top speed very much, but cross-sectional area of your body (which we can imagine goes up with weight) does. Are your tires at 20 psi or higher? Is your chain in decent condition and well lubricated?

And, is there any possibility that the previous owner changed the gearing from 15/45 to something lower?

Alexd

No compression numbers tonight. Gonna need an adapter for my compression tester:(

Confused??? I found my old hand held compression tester and ran a check with that. Only gets to about 75psi! Compression is very low but why?

It starts well, idles well(once warm), and runs fine through the lower gears. No smoke at all, no fouling on the plug, etc. Could the valves be so out of adjustment to give these kind of readings?

Not likely, without problems starting too.

While you're at it, change your oil as more than usual contamination might be occurring. I recommend Mobil One 10W-40 or 0W-40, automotive types.

Alexd

Alexd

Nevermind. I doubted the accuracy of the old compression tester so I devised a test. I used the known pressure from my air compressor and checked it against the gauge. WAY off. I'm going to toss this tester and build an adapter for my good tester. I'll report back again tomorrow.

There are compression tests, and leak-down tests. I believe compression tests are preferential to warmed up engines (and oil).

Alexd

This is right in the middle of the 3 aluminum openings and facing down to the ground right? Is it part #34-35 on this chart and if so how would you get a drill bit in there without removing the carb? Any vids showing how to do this without removing the carb? Thank

OEM Carb Parts

Here's a vid I found, ( but with the carb removed )

Cap Removal

Kenny4

Yes, its the brass plug in the boss that faces down. There may be a very small hole in it already. You can loosen the clamps and rotate the carb in place without removing the throttle cables. Rotate it about 45 deg and you can get at the plug to remove it.