Beta RX350 2 Stroke!

Tokyo_Tiddler wrote:

For any of you guys playing with the 2025 300 RX carb jetting, I found the N1EH needle slightly lean.. it made the power very linear...

For any of you guys playing with the 2025 300 RX carb jetting, I found the N1EH needle slightly lean.. it made the power very linear, but I lost too much power and don't recommend. A good compromise is the NR8G (2016 KTM 300 SX needles) needle in the 3rd clip position for more linear power, but since then I decided I prefer the oem needle even with the mid-range hit to get over the bigger stuff and went back to the stock N0ZD needle, but kept the leaner 178 main/ 40 pilot jets at sea level.  My assessment of the stock jetting is that it is just too rich below 1/4 throttle, but about right above 1/4 throttle. At this point, I feel that playing with the needle will get rid of the hit, but at the expense of too much torque and seemed to be a waste of time for MX. I had to go back to 3 turns out on the airscrew even with the #40 pilot so perhaps a #38 or #36 pilot would be better.

TDC wrote:

When I see NOZx needles mentioned, it reminds me of KTM's that ran too rich up to 1/4 throttle. Initial cure was ppl went to leaner...

When I see NOZx needles mentioned, it reminds me of KTM's that ran too rich up to 1/4 throttle. Initial cure was ppl went to leaner slides, as pilots had no cure. Then came long the Sudco single tapper needles, years later followed by Suzuki triple tapper. 

300:s liked the mid linear CEK and my 200 gained low end torque, offering a snappy linear powerband with the DDK. Enough so that I had to adjust my PV from too early a hit.

Tokyo_Tiddler wrote:

For any of you guys playing with the 2025 300 RX carb jetting, I found the N1EH needle slightly lean.. it made the power very linear...

For any of you guys playing with the 2025 300 RX carb jetting, I found the N1EH needle slightly lean.. it made the power very linear, but I lost too much power and don't recommend. A good compromise is the NR8G (2016 KTM 300 SX needles) needle in the 3rd clip position for more linear power, but since then I decided I prefer the oem needle even with the mid-range hit to get over the bigger stuff and went back to the stock N0ZD needle, but kept the leaner 178 main/ 40 pilot jets at sea level.  My assessment of the stock jetting is that it is just too rich below 1/4 throttle, but about right above 1/4 throttle. At this point, I feel that playing with the needle will get rid of the hit, but at the expense of too much torque and seemed to be a waste of time for MX. I had to go back to 3 turns out on the airscrew even with the #40 pilot so perhaps a #38 or #36 pilot would be better.

TDC wrote:

When I see NOZx needles mentioned, it reminds me of KTM's that ran too rich up to 1/4 throttle. Initial cure was ppl went to leaner...

When I see NOZx needles mentioned, it reminds me of KTM's that ran too rich up to 1/4 throttle. Initial cure was ppl went to leaner slides, as pilots had no cure. Then came long the Sudco single tapper needles, years later followed by Suzuki triple tapper. 

300:s liked the mid linear CEK and my 200 gained low end torque, offering a snappy linear powerband with the DDK. Enough so that I had to adjust my PV from too early a hit.

Tokyo_Tiddler wrote:

I have heard about the Suzuki needles also.  The N1EH and N8RG needles did lean it out below 1/4 throttle and I was able to turn...

I have heard about the Suzuki needles also.  The N1EH and N8RG needles did lean it out below 1/4 throttle and I was able to turn in the air screw, but they had too much of a negative impact above 1/4 throttle. Just need to find one that has the right taper. Another issue I have notice my Keihin carb slide has started to gall and the bike only has about 9 or 10 hours.

TDC wrote:

When I see NOZx needles mentioned, it reminds me of KTM's that ran too rich up to 1/4 throttle. Initial cure was ppl went to leaner...

When I see NOZx needles mentioned, it reminds me of KTM's that ran too rich up to 1/4 throttle. Initial cure was ppl went to leaner slides, as pilots had no cure. Then came long the Sudco single tapper needles, years later followed by Suzuki triple tapper. 

300:s liked the mid linear CEK and my 200 gained low end torque, offering a snappy linear powerband with the DDK. Enough so that I had to adjust my PV from too early a hit.

Tokyo_Tiddler wrote:

I have heard about the Suzuki needles also.  The N1EH and N8RG needles did lean it out below 1/4 throttle and I was able to turn...

I have heard about the Suzuki needles also.  The N1EH and N8RG needles did lean it out below 1/4 throttle and I was able to turn in the air screw, but they had too much of a negative impact above 1/4 throttle. Just need to find one that has the right taper. Another issue I have notice my Keihin carb slide has started to gall and the bike only has about 9 or 10 hours.

TDC wrote:

DIY the slide cutaway and correct the rich initial 1/4 and use your best mid to top needle. No harm in mod'ing the galling slide, eh?

Tokyo_Tiddler wrote:

Thanks.. yeah I was reading about the dyi side cutaway mod with a dremel tool. That seems worth trying. I also looked into the price of...

Thanks.. yeah I was reading about the dyi side cutaway mod with a dremel tool. That seems worth trying. I also looked into the price of a new Keihin PWK slide.. $295 for just a slide!

Tokyo_Tiddler wrote:

Thanks.. yeah I was reading about the dyi side cutaway mod with a dremel tool. That seems worth trying. I also looked into the price of...

Thanks.. yeah I was reading about the dyi side cutaway mod with a dremel tool. That seems worth trying. I also looked into the price of a new Keihin PWK slide.. $295 for just a slide!

FGR01 wrote:

$295?   Is that buying it OEM from Beta?  You should check JD Jetting for less insane pricing.

Tokyo_Tiddler wrote:

Thanks.. yeah I was reading about the dyi side cutaway mod with a dremel tool. That seems worth trying. I also looked into the price of...

Thanks.. yeah I was reading about the dyi side cutaway mod with a dremel tool. That seems worth trying. I also looked into the price of a new Keihin PWK slide.. $295 for just a slide!

FGR01 wrote:

$295?   Is that buying it OEM from Beta?  You should check JD Jetting for less insane pricing.

Tokyo_Tiddler wrote:

Yes, that is from Beta. I checked a few other places since it is a generic Keihin part, and it was a little cheaper around $230...

Yes, that is from Beta. I checked a few other places since it is a generic Keihin part, and it was a little cheaper around $230 (KTM) to $250. I won't use the cheaper knock-offs from China. I don't remember carb slides being this expensive. The little holder cap that crews on the top of the needle is $40 from KTM and you would expect the price to be only $2-$5.  I was going to take the slide back out and take some pics to show Beta as they are usually good about taking care of defects. I also need to reach in the carb with my finger and feel if there are any sharp edges causing the scratches.

FGR01 wrote:

$295?   Is that buying it OEM from Beta?  You should check JD Jetting for less insane pricing.

Tokyo_Tiddler wrote:

Yes, that is from Beta. I checked a few other places since it is a generic Keihin part, and it was a little cheaper around $230...

Yes, that is from Beta. I checked a few other places since it is a generic Keihin part, and it was a little cheaper around $230 (KTM) to $250. I won't use the cheaper knock-offs from China. I don't remember carb slides being this expensive. The little holder cap that crews on the top of the needle is $40 from KTM and you would expect the price to be only $2-$5.  I was going to take the slide back out and take some pics to show Beta as they are usually good about taking care of defects. I also need to reach in the carb with my finger and feel if there are any sharp edges causing the scratches.

FGR01 wrote:

Check this site for Genuine PWK slides at $189.    https://www.keihin-fcr.com/index.php?route=product/product&product_id=775

 

Tokyo_Tiddler wrote:

Thanks.. yeah I was reading about the dyi side cutaway mod with a dremel tool. That seems worth trying. I also looked into the price of...

Thanks.. yeah I was reading about the dyi side cutaway mod with a dremel tool. That seems worth trying. I also looked into the price of a new Keihin PWK slide.. $295 for just a slide!

FGR01 wrote:

$295?   Is that buying it OEM from Beta?  You should check JD Jetting for less insane pricing.