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Beta 520 de-smog and re-jetting

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Hey guys. I'm getting ready to de-smog and rejet my 2011 Beta 520RS-sm. I have an FMF Q4 exhaust on it.

1) Does anyone have any pointers as far as the de-smog is concerned?

2) Has anyone rejetted a 520RR or RS with a Q4 exhaust? Can you take some guess work out of it for me?

(by de-smog, I mean parts of the smog control have fallen out, and I'm...uhhh... stuck in a trail right now (on a supermoto?), and I have all my tools with me. I just need to know how to plug it up so I can get out of the woods... right)

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Hey guys. I'm getting ready to de-smog and rejet my 2011 Beta 520RS-sm. I have an FMF Q4 exhaust on it.

1) Does anyone have any pointers as far as the de-smog is concerned?

2) Has anyone rejetted a 520RR or RS with a Q4 exhaust? Can you take some guess work out of it for me?

(by de-smog, I mean parts of the smog control have fallen out, and I'm...uhhh... stuck in a trail right now (on a supermoto?), and I have all my tools with me. I just need to know how to plug it up so I can get out of the woods... right)

178 main. Remove hose from carb and plug hole with screw. Perform canisterectomy. Re-route gas cap hose to frame. Ride.

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178 main. Remove hose from carb and plug hole with screw. Perform canisterectomy. Re-route gas cap hose to frame. Ride.

Simple enough! Thank you!

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HOSES ARE EVERYWHERE!

To add to what you said, We took the engine oil breather hose out of the carb and closed that up, so that the engine will get some clean air.

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I rejetted with the JD Jet Kit and just followed directions and it was spot on.....comes with the diaphram spacer and proper tapered needles as well as jets. I also put a heavier accelerator pump spring in it "Merge AP Spring" for better throttle response. Great setup. I also ditched the crankcase breather into the carb and capped the carb nipple so I could use a case vent by Thumper Racing. http://thumperracing.net/index.php?route=product/product&path=246&product_id=212

Edited by dirtwiz

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I rejetted with the JD Jet Kit and just followed directions and it was spot on.....comes with the diaphram spacer and proper tapered needles as well as jets. I also put a heavier accelerator pump spring in it "Merge AP Spring" for better throttle response. Great setup. I also ditched the crankcase breather into the carb and capped the carb nipple so I could use a case vent by Thumper Racing. http://thumperracing.net/index.php?route=product/product&path=246&product_id=212

I wonder if the one way case vent valve is as essential here as it is in the KTM RFS engine?

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Good point. I'm not sure if its a big deal on the RFS motor either but I don't like the idea of a oily vapors being ingested by my carb and motor or dust and grit finding its way back into my crankcase or worse yet the bike going upside down and cranckcase oil running into your vent hose and being belched into your carb. KTM Supercross riders had this problem so they changed it after embarassing themselves with clouds of smoke coming out of their bikes after crashes. Some people also run the crankcase vent hose to a small UNI breather filter and insert it into the backbone of the frame above the valve cover. Still vents nicely and just needs occasional cleaning. Here is a link to one that fits into the frame of the RFS generation Beta...might fit the new ones too. It is part number UP-102

www.unifilter.com/online%20catalog/universal.html If I had it to do over again I would save some money and probably do it this way.

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just my 02 fwiw, but that alot of money for an automotive inline pvc valve. Which IMO does not do what it's advertised to do. Engines that do use this theory (ducati for example) use a reed valve system that can actually move quick enough to follow the pressure pulses. A pvc type check ball doesn't. Sorry for being a butt about this, think your better off with an open hose vent with proper routing.

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just my 02 fwiw, but that alot of money for an automotive inline pvc valve. Which IMO does not do what it's advertised to do. Engines that do use this theory (ducati for example) use a reed valve system that can actually move quick enough to follow the pressure pulses. A pvc type check ball doesn't. Sorry for being a butt about this, think your better off with an open hose vent with proper routing.

No aplogies needed...I appreciate the input and you may very well be right. According to the people selling them (LOL) these "special made valves" are capable of very high rpm use while regular automotive PCV valves will fail and stick, or not keep up....lots of people run these cheaper options but who knows for sure. My $75 valve has been working for over 4,000 street miles for what that's worth. If you remove the crankcase vent hose and put your finger over the end you will feel the pulsing and it makes you wonder how much could get sucked in....also I don't know what this high speed pulsing would do to fuel flow in a carb. I do know crankcase pressure can be an issue on a RFS motor since when I got mine the previous owner has just changed the oil, over filled it, and I flogged it for 5 minutes and blew the case gasket out. Easy repair but I realized not to have the oil above the bottom of the sight glass when cold since it can't handle much pressure. HOWEVER...Dave Hopkins is one of the top KTM motor builders in the country and he claims we should just leave the crankcase vented into the carb. What could he possibly know that I don't know...(LOL).

Edited by dirtwiz

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HOSES ARE EVERYWHERE!

To add to what you said, We took the engine oil breather hose out of the carb and closed that up, so that the engine will get some clean air.

Yeah. Betas are hose endowed. For simplicity and expediency I left the black box with all the hoses on the bike. Less work and no need to buy more hoses with correct length due to black box removal.

With sub frame Carb and tank off for other work I have now removed black box and installed requisite hoses of correct length.

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Yeah. Betas are hose endowed. For simplicity and expediency I left the black box with all the hoses on the bike. Less work and no need to buy more hoses with correct length due to black box removal.

With sub frame Carb and tank off for other work I have now removed black box and installed requisite hoses of correct length.

I didn't remove the Black box. Just drill a hole in the side, or remove the allen plug in the back. I left it on to keep everything looking pretty.

Other than that, I just removed all the hoses that came from the black box.

As far as the Case vent is concerned, I just vented it out into the air without any valve or anything. Works great for my Supermoto w/o any real dust in the air. I may stuff some foam into the tube or something later for a filter, and keep it cleaned out.

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I hate to bring an old thread back from the dead, but I can't seem to find any "road" reports on the beta 520rs. I found one for sale locally with a set of sumo wheels AND standard knobbie setup. I just wanted to know how the 520 is on the street/short stretches of interstate. I'm looking at selling my CBR and using the sumo setup to cover my street riding, with the dirt setup on DS adventures. Thanks!

PS- I'm in AFG for a few more months, so arranging a test ride for myself is impossible. I would be having one of my friends pick the bike up for me. It's practically showroom new (2011) and comes with quite a few extras- Would hate to see such a deal slip by me!

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just my 02 fwiw, but that alot of money for an automotive inline pvc valve. Which IMO does not do what it's advertised to do. Engines that do use this theory (ducati for example) use a reed valve system that can actually move quick enough to follow the pressure pulses. A pvc type check ball doesn't. Sorry for being a butt about this, think your better off with an open hose vent with proper routing.

That is 100% correct. I always just leave the crankcase vent out to open air or use a little "Unifilter" with nipple at the end...

As far as jetting, It is extremely subjective from rider to rider. With my Leo Vince exhaust and stock airbox, I'm running a 175 main, 45 pilot and I think middle position on the needle. The coolest adjustment is the remote fuel screw. I turn it in or out a little bit depending elevation changes.

I may get an adjustable leak jet someday. But for now, my Beta 520RS runs every bit as good or better than any fuel injected bike out there. The only real advantage of FI is the mileage. FI bikes get sick fuel economy.

Edited by ballisticexchris

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That is 100% correct. I always just leave the crankcase vent out to open air or use a little "Unifilter" with nipple at the end...

As far as jetting, It is extremely subjective from rider to rider. With my Leo Vince exhaust and stock airbox, I'm running a 175 main, 45 pilot and I think middle position on the needle. The coolest adjustment is the remote fuel screw. I turn it in or out a little bit depending elevation changes.

I may get an adjustable leak jet someday. But for now, my Beta 520RS runs every bit as good or better than any fuel injected bike out there. The only real advantage of FI is the mileage. FI bikes get sick fuel economy.

Well, I don't agree with the FI bike getting sick fuel economy. My TE450's and SM610 now powered up are sucking fuel hard. My Beta 520 now that I have it back after all the smog crapola fell of I have not tested. Will be checking it soon though. But oh how I love my 12 520RS

As far as the little black box I would get the UP-tite carb filter and eliminate that thing. All the other stuff is subjective, no new needles or jets are used on mine after build up.

Edited by mirrorimage

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Well, I don't agree with the FI bike getting sick fuel economy. My TE450's and SM610 now powered up are sucking fuel hard. My Beta 520 now that I have it back after all the smog crapola fell of I have not tested. Will be checking it soon though. But oh how I love my 12 520RS

As far as the little black box I would get the UP-tite carb filter and eliminate that thing. All the other stuff is subjective, no new needles or jets are used on mine after build up.

The only reason I was saying fuel injected bikes getting the sick fuel economy, was a crazy KTM500 that was riding with our group in the Moonlight Madness ride. When we stopped for fuel (aprox 70 miles) he put a little more than a gallon and I was over 2 gallons to fill mine.

That carb filter looks to be the answer for cleaning things up. Sounds like our Betas are getting dialed in nice!

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