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Old 05-05-2013, 02:48 PM   #946
Alacrity
Semi Pro Bar Vaulter
 
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Joined: Jul 2008
Location: Flyover Country - Unless I'm Elsewhere
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Originally Posted by GEORGE K View Post
Good idea or bad idea? It seems to only add to the complexity and weight of an otherwise simple bike. Has anyone out there done it? If so what is needed to cap off and stow things?

Thanks.
AIS is easy to remove, no ill effects to performance, as Ron notes. Makes things a bit easier to get to as well.

Items you will need is a blanking plate for the cylinder (where the metal flange attached) and a small cap where the hose fit on the other end. Thats all.
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Old 05-05-2013, 04:21 PM   #947
GEORGE K
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Location: Gig Harbor, Wa.
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Rejet parts problem...

Got my carb off, float bowl dropped, and main jet removed. Then the disappointment. The parts guy at Brother's motorsports in Bremerton, Wa. had guaranteed me the 140 jet he was selling me would work. Wrong! I told him specifically that it was for a 2008 XT250. The jet he sold me is about 1/2 inch long and does not have clearance in the bowl. The original jet is about 1/8 inch long. Needless to say the parts manager and I are going to have a chat about the lack of competance of his help! And then I will probably have to wait for a jet to be ordered! Meanwhile I am missing some beautiful riding weather, crap!!
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Old 05-05-2013, 10:20 PM   #948
Zojirushi
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Location: El Paso Del Norte
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Originally Posted by ssregal39 View Post
What did you used to ride and how tall are you?
5'11 and I have owned XR650L, DRZ400S, F800GS, Triumph Tiger, Ural Patrol, CB500 four, and a Yamaha Roadstar Warrior.
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Old 05-06-2013, 09:17 AM   #949
150ron
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Location: Valencia, ca
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Quote:
Originally Posted by GEORGE K View Post
Got my carb off, float bowl dropped, and main jet removed. Then the disappointment. The parts guy at Brother's motorsports in Bremerton, Wa. had guaranteed me the 140 jet he was selling me would work. Wrong! I told him specifically that it was for a 2008 XT250. The jet he sold me is about 1/2 inch long and does not have clearance in the bowl. The original jet is about 1/8 inch long. Needless to say the parts manager and I are going to have a chat about the lack of competance of his help! And then I will probably have to wait for a jet to be ordered! Meanwhile I am missing some beautiful riding weather, crap!!
all you need to know is here

http://www.xt225.com/forums/ubbthrea...9291#Post89291
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Old 05-07-2013, 04:07 AM   #950
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Highway or city riding, no problem!

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Originally Posted by ALinUTAH View Post
I cruise at 60mph with a load of camping gear, but only if it's flat and there is no headwind. It will do a little more than that under ideal conditions but it's not something I count on or do regularly. It's smooth at 60 vibe-wise. But no way would I ride something like an XT250 in congested urban freeway traffic. I would go 100 miles out of my way if that's what it took. Personally, I enjoy touring on mine but I avoid highways and big cities.
I ride my XT250 everyday to commute to work, 30km. Half of that is highway 60mph+ and the other half is city (small streets, lots of red lights, sometimes bumper to bumper).

That little bike just soldier on and demands more. Just yesterday I was stuck in traffic because of construction, idling almost without moving for at least half an hour. The engine was puting out lots of heat, but it doesn't seems to be a problem (just check the oil often!)

Last summer I did a 1200km camping trip, fully loaded with my hard panniers and top case. I did a gps verified 120 km/h (75 mph) but I usually keep it at 100 km/h (62 mph) because it's more comfortable. I had trouble keeping up the speed once on a hill, doing only 90 km/h (55 mph) at WOT.

The thing that transform the way my bike rides on the highway is a windshield. Now I can comfortably ride at those speeds and can even take a hand off the handlebar. Before I was hanging on and it felt like my arms where streching
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Old 05-08-2013, 09:21 PM   #951
GEORGE K
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Location: Gig Harbor, Wa.
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140 main jet running problems

I have a 2008 with FMF Powercore 4 exhaust. With the idle jet at 3 turns out and a stock 135 main jet the bike ran sweet and strong throughout the power band. Based on others experiences I changed to a 140 main jet for stronger performance when running on the main. I am at sea level and it was about 65 degrees for my test run with the 140. When at half throttle or greater or when trying to accelerate using more than half throttle the bike quickly stalls and surges like it is fuel starved and then gets fuel. This continues when ever above half throttle, but runs okay at less throttle.

Has anyone else encountered this? What to do next? I hate to put the 135 jet back in because it is a pain in the butt! Could it be an air flow cavitation problem? I am thinking of pulling the filter out for a short run to see if things change.

Any other ideas out there?

Thanks,
George
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Old 05-08-2013, 09:30 PM   #952
150ron
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Quote:
Originally Posted by GEORGE K View Post
I have a 2008 with FMF Powercore 4 exhaust. With the idle jet at 3 turns out and a stock 135 main jet the bike ran sweet and strong throughout the power band. Based on others experiences I changed to a 140 main jet for stronger performance when running on the main. I am at sea level and it was about 65 degrees for my test run with the 140. When at half throttle or greater or when trying to accelerate using more than half throttle the bike quickly stalls and surges like it is fuel starved and then gets fuel. This continues when ever above half throttle, but runs okay at less throttle.

Has anyone else encountered this? What to do next? I hate to put the 135 jet back in because it is a pain in the butt! Could it be an air flow cavitation problem? I am thinking of pulling the filter out for a short run to see if things change.

Any other ideas out there?

Thanks,
George
Try running it with the air filter cover off, i left mine off, and just used a piece of something i had laying around to keep it in place, like this.



bike needs more air to go along with more fuel,

also, take the air filter out, and if dirty replace it, or you can clean it with compressed air, hitting it against something, and i used to stick the workshop vaccum in it and it would suck out a lot of the dust.
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Old 05-10-2013, 12:50 AM   #953
kdtrull
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Quote:
Originally Posted by GEORGE K View Post
I have a 2008 with FMF Powercore 4 exhaust. With the idle jet at 3 turns out and a stock 135 main jet the bike ran sweet and strong throughout the power band. Based on others experiences I changed to a 140 main jet for stronger performance when running on the main. I am at sea level and it was about 65 degrees for my test run with the 140. When at half throttle or greater or when trying to accelerate using more than half throttle the bike quickly stalls and surges like it is fuel starved and then gets fuel. This continues when ever above half throttle, but runs okay at less throttle.

Has anyone else encountered this? What to do next? I hate to put the 135 jet back in because it is a pain in the butt! Could it be an air flow cavitation problem? I am thinking of pulling the filter out for a short run to see if things change.

Any other ideas out there?

Thanks,
George
When I tried the 140 main, at El. 560, warm weather, stock but drilled pipe, I had the same problem. Filter cover off helped but not enough. The only way it was rideable was when I completely removed the air filter. I gained insane, low end, rip across the yard, power and could sling dirt like the big boys. On the road, new problems popped up. Whenever I rolled off the throttle from high speed/rpm, I got abrupt, destabilizing stalls. Tinkered with air box flow some more and every win produced an equal loss somewhere else in the rpm range. It was so great for ripping launches and power slides...it was very disappointing to undo the whole jet/air box mod to get tolerable, full range results back. But man....it was fun for a few short hours. The no filter limitation was a deal-breaker. I may give it another go some day. I think the key component to making this work is to overcome the chaotic flow that has to be going on inside that multi-chamber air box...especially that little supplemental puffer box that is soft-rubber mounted on top. WTH is that thing for anyway???

kdtrull screwed with this post 05-10-2013 at 01:05 AM
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Old 05-10-2013, 05:24 AM   #954
GEORGE K
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Thanks!

Thanks for that input. I am away from the bike for about a week but will play around with the intake restrictions when I get back. I am in no hurry to go back to the 135 jet unless I do not get good stumble free performance from idle to wide open. I had that with the 135. It surprises me how much effect the 140 has. Maybe a 137.5 would be good if one could be found.
That little rubber thing is a mystery to me too! More to learn about this machine...
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Old 05-10-2013, 05:55 AM   #955
NJ-Brett
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You really need to tune a carb all the way through.
You can not just change the idle mixture and main jet and call it good.
Vacuum carbs have even more interactions, and you need to set the mixture AFTER doing intake and exhaust mods, and that includes the pilot circuit, the needle, and the main jet, at various rpm's and throttle openings.

The needle jet (position and taper) does all the mid throttle work, pilot circuit does idle and just off, main jet does 3/4 throttle and up, and they all overlap a bit.

Then there is the vacuum slide operation, most are slow.

If you really want some fun, fit a pumper carb, instant throttle response, no odd vacuum carb stuff like low rpm vacuum slide vibrating, you can set the needle lower to lean out the mixture a bit and get great mpg but still get great throttle response and a nice rich full throttle operation.

Untill you try a pumper carb, you have no idea just how sucky vacuum carbs are.
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Old 05-10-2013, 09:27 AM   #956
GEORGE K
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Joined: Apr 2004
Location: Gig Harbor, Wa.
Oddometer: 45
Good input

Thanks. Good info. I understand the transition of fuel flow as you describe it. In my case the surging starts and continues from about half throttle to full and doesn't clear. I hear you on the vacuum carb thing but just wanted to get a bit more fuel flow to keep from running too lean with the new exhaust. It was running great before the jet change and mostly I just want a good reliable bike. I may open up air flow a bit to see if it changes, and then move the needle up a bit. If that doesn't work I will probably go back to the 135 and ride it...
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Old 05-10-2013, 10:12 AM   #957
NJ-Brett
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You can do a plug check to get an idea if its lean or rich.
Some air boxes/filters are very restrictive, and when you open them up the bike goes way lean, other bikes it does little.

Since most bikes are set up to pass the epa tests at something like 45 mph and at idle, I would think the needle would be set very lean.
Most bikes seem to need a different needle to work well, shimming it up gives mixed results.

When I fit dynojet kits to some carbs, the needle was a LOT different looking....
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Old 05-10-2013, 06:32 PM   #958
GEORGE K
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Joined: Apr 2004
Location: Gig Harbor, Wa.
Oddometer: 45
Thanks!

Quote:
Originally Posted by GEORGE K View Post
Thanks. Good info. I understand the transition of fuel flow as you describe it. In my case the surging starts and continues from about half throttle to full and doesn't clear. I hear you on the vacuum carb thing but just wanted to get a bit more fuel flow to keep from running too lean with the new exhaust. It was running great before the jet change and mostly I just want a good reliable bike. I may open up air flow a bit to see if it changes, and then move the needle up a bit. If that doesn't work I will probably go back to the 135 and ride it...
Thanks Brett. Very helpful to hear from the voice of experience.
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Old 05-10-2013, 10:12 PM   #959
150ron
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I shimmed my needle on the XT, made it pull stronger, could feel it for sure right away.

Since its non adjustable, i added a small shim under it, to raise it up a bit.
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Old 05-11-2013, 05:24 AM   #960
GEORGE K
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Needle Shim

Cool, I will try that for sure. The more I think about it the more I think I have a transition to the main jet issue so shimming the needle is the thing to try. Along with the improved airflow stuff.
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