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Carb adjustment after removing Spark arrestor?

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Just took the spark arrestor (I believe that is the name) out of the muffler on my XT350. Just the tip piece. Sounds good and seems to be running okay. But Im wondering if that is something that needs to have the carb adjusted to account for? Since there is now less compression/pressure in the exhaust, right?

 

Thanks for the help you guys have given me so far. Im trying to have my XT running as nice as the day it was built, but it isnt so easy when you are only a little mechanically inclined with no motorcycle experience. 

Edited by Thatslyb

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Well...

Mine's a 94, I also removed the spark plate. I dont think it's enough of a difference to need serious adjustment. But when I opened my airbox up too, I noticed it slightly hesitated intermittently.  So I turned my fuel/air screw to run rich 3 turns out(right behind boot on primary carb, bottom of left carb, and adjusted my secondary carb to engage early at 1/4 throttle. That made it purrr.

It took me some tinkering with the primary/secondary carb to get mine just right...

If you do adjustments, its good to make sure the jets & carb are clean before adjusting. Mine didn't have a filter on the fuel line.  It had crap down in the gas inlet, where the tank hose goes. It was basically dirt & tiny mulch that had gotten in the tank over the years. I didn't find it at first.

All bikes have their own personality, so first thing I do before adjustments is clean the carbs, then make sure the boots aren't leaking.  Next, check the boots again. I use Napa 1 1/4" heater hose & clamps for boots.  

Once you're sure your carbs are clean and boots aren't leaking... Turn up idle to 1500rpms to hear it better while you adjust the fuel/air screw. Use a little flathead screwdriver for eyeglasses, if you dont have anything short enough and you are crafty you can grind down a nail or something so you can adjust without carb removal. Turn the screw carefully and never go real tight, start at 2.5 turns out, adjust and listen or watch the rpms. Find the sweet spot where it idles highest. The adjustments take a few seconds to take effect so be patient but also dont let the bike get too hot. This should be done after any mod, I do it once a year no matter what.

Then you might want to adjust the secondary carb (right side carb) to move the extra balls around the mid rpm area.  The secondary engage adjustment is on top inbetween the carbs, it's an 8mm and once the nut is loose you can probably turn the screw with your fingertips without taking the carbs out.  Too soon(no gap) can make it so rich it hesitates at 3-4k rpms as well as redlines at 6k. Too late(big gap) and it might get lean or surge in high rpms. Mine is set so that its about 1/8" or 3mm gap between the roller & the lever. By making it engage earlier it gets a lil more gas in the mid rpms. Some models have the lever reversed but they are all made stock to engage somewhere near half throttle.

They come with kinda small jets, if you went bigger jets you'd definitely need to check both of these adjustments. But because of the small jets I feel like running it just a lil rich makes up slightly and the secondary set a touch early is also helpful, especially if you have a 1mm over-bore piston or if you open the exhaust or intake. -Cheers

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Thank you for your reply I will take all of that into account.

 

A question I have is you mention turning idle up to 1500... I have my bike idling at around 1650ish. What is the idle typically on these bikes? I figured having it idle a little high would make starting (and staying running) easier

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Yes! Its true... Idling somewhere around 1500 is usually perfect.  I meant to say higher than 1500.  2000-2500 should be enough to make adjustments noticeable and it should takes about 10 seconds or less to take effect.

Its true... Idling somewhere around 1500 is usually perfect.  I meant to say higher than 1500.  2000-2500 should be enough to make adjustments noticeable and it should takes about 10 seconds or less to take effect.

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