Idle Issue

[yamahinn03]

O.K. MY 03 has mnever had the carbs cleaned so Sat. I pulled them and they were suprisingly clean but nonetheless a piece of mind. Monday I filleder up with fresh oil and fired it up and ran good except idle seemed funny, played with it for awhile and got it to sit at 1500rpm. Today Istarted it and let it warm up moved it about 20ft and let idle somemore, then it seemed to idle up and down not real high but enough to be noticed just acouplehun rpm or so. ???????????????????????????????????????????????????????????????????????????????????????????????????? Any Ideas???????????????????????????

 

[SnoWarrior]

Did you set the idle screws to 2 turns out, and did you sync the carbs?
If not you may want to do that.

 

[Warrior Snowman]

carbs can look clean and have those tiny idle jets clogged just enough to make idling difficult. I soak the idle jets in carb cleaner then blow them out. Some on this forum use something to push through the jets (no drill bits!) to clean them out. This made all the difference in the world in how my sled ran. I found that there was no need to reset or re sync my carbs after this job.
Good luck!!

 

[SlvrRx998]

I would defenitley pull the jets out and use a fine wire off of a brush or something small enough to push the gunk out without damaging them. Even if you think they are clean, they most likely aren't! You said yourself it has never had them cleaned. I've had to clean mine twice within the past month already. The jets are very small and plug up easily. Start from there and sync the carbs.

 

[jdp1under]

I ALWAYS USE THE WIRE INSED A BREAD TWIST TIE OR GARBAGE BAG TWIST TIE WHEN I CLEAN THE JETS. FITS GOOD AND WONT DAMAGE ANTHING! I AGREE WITH THESE GUYS LOOKS CAN BE DECIVING!!!!!!!!!!!

 

[yamahinn03]

I did have the carbs all apart and did clean all the needles but i guess i will be going in there again... Thanx for the input.

 

[Len Todd]

If the Pilot screws are set to two turns out and you still get that slightly high idle after a rev, one of the pilot jets is partially plugged. I use a bristle from a wire brush to rod out the Pilot Jets. Then squirt carb cleaner through it. If you squirt it from the slotted end and hold you finger over the ends of the slots, the carb cleaner will give you a nice round solid squirt that will travel 10' horizontally. Once you can get that squirt, you got it clean.

I too did not ever clean mine until last Spring. Then, I left the carbs drained. And guess what? I have had to clean them 3 times already this season to get all the varnish flakes out . One of my main jets fully plugged two nights ago. So, ... I am again from the camp that says; "keep the carbs wet over the summer. Use fuel stabilizer and bring the engine up to operating temp monthly."

Oh, ... Once I got the carbs clean, she really rips again. I was suspicious last season that they needed cleaning cause top end and the shift RPM were down a bit. But, right now, the RPMs and top end is right back where it was when I put in the Stage II a couple years ago (i.e. 10,200 off the line, 9,950-10,000 on hookup and right back to 10,200 for the run, 10,300+ at Top End ... kind hard to really tell when you are streakin' down the trail at top end.)

 

[yamahinn03]

Ihave the idle screws at 2.5 turns, ithink this is the problem. When I took them apart first time they were 2 @ 2.5 and the other 2 at 1.5 and 2 so I decided to go with majority < guess I was wrong. Anybody know what spec is ? Rode tonite ran awsome except for idle jumpin all over.

 

[jd0270]

I would definitely hook up a vacume mate to it and check the synchronization.... and ideally a exhaust gas analyzer too. I would start at 2-1/4" turns out on all of them(spec is 2 I think). I am lucky to have access to all of these tools lol.

Also instead of wire I let the jets soak immersed in Yamaha combustion chamber cleaner for an hour, blow out with compressed air. One of the few products in a can that will dissolve the varnish/crap from gas in carbs... though it does take time, but there is no chance of damage.

 

[RedRocket]

Anybody know what spec is ?

Spec is "Approx 2", I run at 2.5 turns out and it works very good for my elevation (700ft ASL) and the plugs have the exact color that I like. Sled is a stock 03 RX-1.

 

[yamahinn03]

Well got carbs cleaned up pilot screws reset and it ran great for about 3 minutes and then idle jumped about 500 rpm for no reason, touch the throttle and it goes back to normal. This doesnt happen all the time just spuraticly.....................

 

[Len Todd]

You could still be getting bad fuel up into your clean carbs. I had to do mine three times this year. The last time I hit it with 1 gallon of fresh gas and enough carb cleaner for 8 gallons. This caused a lot of crud to release. Then, I removed the carbs for cleaning and flushed the fuel lines and added more fresh fuel. Seems to be O.K. now. You may need to flush out the old fuel totally and re-clean the carbs.

Oh, ... the other thing i noticed yesterday was that as I tightened the clamps on the air-box to the carbs, two boots were allowing the clamp to roll off the carb on the bottom. It is really subtile. But when it happens, the air box connections leak. That too causes the idle to be a little lean. So, ... You may want to double-check the air-box is sealing on the carbs correctly also.