NIBBI 28 carb for CSC TT250....YES!! - Page 2

RedCrowRides · 09-05-2020, 02:30 PM

I don't know if it is possibly some mechanical difference between the Nibbi 30 and 28 ,or if the underlying complication factor is the engines just dont have the flow to smooth out the 30 as well as the 28, but a recurring theme on many of the Thumper Boards has been trouble tuning the Nibbi 30 , while the 28 has far fewer complaints.

In any case the Nibbi 28 ought to be plenty of carb even with some pretty strong engine mods ,so were it me I'd go with the 28 rather than the 30 for easier tuning ,this is purely anecdotal evidence and i'm sure many ppl have been able to get the 30 where they wanted it but between here, Thumper Talk, and the RXB Owners Group FaceBook Community there is a definite recurring theme about issues jetting / tuning the Nibbi 30 versus the Nibbi 28. The 28 seems like for whatever reasons it is at least able to run with a far wider set of parameters while the 30 pretty much won't allow the Bike to be ridable at all unless it is near to perfectly jetted / adjusted.

Bob Kelly · 11-04-2022, 12:16 PM

Hi guys ! I know this is an old thread but figured I'ed post here that I just got a Nibbi 30mm carb from Amazon.... simply because the 2021 CSC TT250 comes with too small of a carb for my liking, back in the 1970's every 250cc bike (most 2 stroke machines) all came with 32MM carbs a few Honda's came with 30MM carbs if I recall.... but this bike I THINK has a 26MM carb (please confirm that as I cannot find any info on what size the stock carb is on this bike !) anyway I got a 30MM carb to put on it and will do that shortly and see if that improves the performance any as it is a very tame bike.
However it is worth noting that a engine is an air pump essentially and if you want it to breathe better you need to remove the exhaust restrictions as well....
the first thing I did when I received this bike was drill more holes in the rear of the muffler and increase the size of the cover cap on the exhaust pipe. and that changed the bike quite a bit. just doing that.
However I am skeptical that I will gain much by just swapping the carbs as there is still the stock exhaust pipe which obviously still is restricting the flow. even with
the 6~ 1/2" holes in the back of the muffler.
the selling point to me was the new placement of the choke the original one is a royal bitch to find to turn it off ! the new carb has a button you pull up on and it stays up till you are ready to turn off the choke/enricher by just pushing down.... and it's far easier to reach !
that being said, I am just hoping it will make a difference in performance as this 250cc bike is rather disappointing in power to me. it's just a putt-putt machine ! it won't break any records or get you into trouble going too fast ! but it is still fun to ride!
I've had over 50~75 motorcycles in the past and miss the old big 2 strokes that would wheelie at the twist of the throttle, so that is probably why I am so disappointed <GRIN> for a play bike it is really Mild !
....
so if anyone knows of a bolt on exhaust system that is something that will help this CSC TT250 breathe better please speak up ! with links as I am rather inept when it comes to windows 11 ! HAHAHAHA
I have no idea if the pipes for the Hawk or Brose will fit this thing or not they should but there are small differences between the models !
Thanks!
Bob........

Bill Hilly · 11-04-2022, 09:53 PM

As coincidence would have it, I just installed a PE28fl on my internally stock TBR7D. I wasn't expecting any performance gain, but Amazon had a good price, and 10 percent coupon I have been running the aftermarket CRF230 type exhaust for a while, and I was very pleased with it. It's supposed to free up a couple HP, and it did make my bike more eager to pull, and seemed like it's more comfortable at higher RPM. I was surprised,but the carb DID a little more of the same effect, but I had switched back to my stock airbox a little while back,and I now am running the foam pod filter with the Nibbi. I am running a 120 main, and 40 pilot, and it runs fantastic, not even the slightest stumble. I was running a 115/36 with the stock carb, and it ran just fine, but it just has a little more wind now. My throttle cable is a hair short, and if I turn it out enough to catch a thread on the lock ring(nut), it want to increase idle speed when I turn the handlebar, but I just taped it .I can also say that the stock airbox tube on mine wouldn't go over the back of the Nibbi https://www.ebay.com/itm/27472535351...b_b_asin_title

Bill Hilly · 11-04-2022, 09:58 PM

Here is link to what I think is a good deal on the carb. I thought I put it on the last post, but it doesn't show up. https://www.amazon.com/gp/aw/d/B0B4V...b_b_asin_title

CheapThrills · 11-10-2022, 09:30 AM

Crap, clicked link to the manifold but Ebay giving me an error. Got a close up pic or maybe another link to click on?

Thx!!!

rambox44 · 08-02-2023, 10:36 PM

I'm trying to install the Nibbi PE28fl on my TT250 but there's not enough room, it's hitting the frame so I can't get it over the manifold bolts. Anybody with more experience able to tell me what my next step should be - different manifold, different carb? Thanks!

This is the one I bought:
https://www.amazon.com/dp/B0BNBGPDS7

**JerryHawk250** · 08-03-2023, 07:36 AM

Quote:

Originally Posted by rambox44

I'm trying to install the Nibbi PE28fl on my TT250 but there's not enough room, it's hitting the frame so I can't get it over the manifold bolts. Anybody with more experience able to tell me what my next step should be - different manifold, different carb? Thanks!

This is the one I bought:
https://www.amazon.com/dp/B0BNBGPDS7

Remove the rubber intake from the engine and attach to the carb first, then bolt the intake back onto the engine.

rambox44 · 08-05-2023, 12:32 AM

Quote:

Originally Posted by JerryHawk250

Remove the rubber intake from the engine and attach to the carb first, then bolt the intake back onto the engine.

That did it, thanks! This bike has always been cold blooded and unreliable, but after getting this Nibbi carb on it started the instant I touched the starter - and it's been sitting for a year. I'll work on getting it dialed in tomorrow and report back.

The Nibbi carb has a tube that elbows down to open air. Is that a vent tube? The bike has an extra tube that connected to the original carb here, should I take off the elbow tube and connect it to the original or just leave them both open?

09-05-2020, 02:30 PM	#16
RedCrowRides Join Date: Jun 2018 Location: Florida Posts: 759	I don't know if it is possibly some mechanical difference between the Nibbi 30 and 28 ,or if the underlying complication factor is the engines just dont have the flow to smooth out the 30 as well as the 28, but a recurring theme on many of the Thumper Boards has been trouble tuning the Nibbi 30 , while the 28 has far fewer complaints. In any case the Nibbi 28 ought to be plenty of carb even with some pretty strong engine mods ,so were it me I'd go with the 28 rather than the 30 for easier tuning ,this is purely anecdotal evidence and i'm sure many ppl have been able to get the 30 where they wanted it but between here, Thumper Talk, and the RXB Owners Group FaceBook Community there is a definite recurring theme about issues jetting / tuning the Nibbi 30 versus the Nibbi 28. The 28 seems like for whatever reasons it is at least able to run with a far wider set of parameters while the 30 pretty much won't allow the Bike to be ridable at all unless it is near to perfectly jetted / adjusted. __________________ 2001 Mustang GT 2004 Sportster 2018 VADER 2020 Orion RXB250L
	1

11-04-2022, 12:16 PM	#17
Bob Kelly Join Date: Jan 2022 Location: Weed, California. Posts: 271	Hi guys ! I know this is an old thread but figured I'ed post here that I just got a Nibbi 30mm carb from Amazon.... simply because the 2021 CSC TT250 comes with too small of a carb for my liking, back in the 1970's every 250cc bike (most 2 stroke machines) all came with 32MM carbs a few Honda's came with 30MM carbs if I recall.... but this bike I THINK has a 26MM carb (please confirm that as I cannot find any info on what size the stock carb is on this bike !) anyway I got a 30MM carb to put on it and will do that shortly and see if that improves the performance any as it is a very tame bike. However it is worth noting that a engine is an air pump essentially and if you want it to breathe better you need to remove the exhaust restrictions as well.... the first thing I did when I received this bike was drill more holes in the rear of the muffler and increase the size of the cover cap on the exhaust pipe. and that changed the bike quite a bit. just doing that. However I am skeptical that I will gain much by just swapping the carbs as there is still the stock exhaust pipe which obviously still is restricting the flow. even with the 6~ 1/2" holes in the back of the muffler. the selling point to me was the new placement of the choke the original one is a royal bitch to find to turn it off ! the new carb has a button you pull up on and it stays up till you are ready to turn off the choke/enricher by just pushing down.... and it's far easier to reach ! that being said, I am just hoping it will make a difference in performance as this 250cc bike is rather disappointing in power to me. it's just a putt-putt machine ! it won't break any records or get you into trouble going too fast ! but it is still fun to ride! I've had over 50~75 motorcycles in the past and miss the old big 2 strokes that would wheelie at the twist of the throttle, so that is probably why I am so disappointed <GRIN> for a play bike it is really Mild ! .... so if anyone knows of a bolt on exhaust system that is something that will help this CSC TT250 breathe better please speak up ! with links as I am rather inept when it comes to windows 11 ! HAHAHAHA I have no idea if the pipes for the Hawk or Brose will fit this thing or not they should but there are small differences between the models ! Thanks! Bob........ __________________ It's too late when you've gone too far !
	0

11-10-2022, 09:30 AM	#20
CheapThrills Join Date: Jan 2021 Location: Lehigh Valley Area Posts: 152	Crap, clicked link to the manifold but Ebay giving me an error. Got a close up pic or maybe another link to click on? Thx!!! __________________ - My 2 Bikes: TaoTao TBR7 Boom Vader Gen 2 (BD125-10) Testing a YouTube Channel
	0

08-02-2023, 10:36 PM	#21
rambox44 Join Date: Aug 2023 Posts: 6	I'm trying to install the Nibbi PE28fl on my TT250 but there's not enough room, it's hitting the frame so I can't get it over the manifold bolts. Anybody with more experience able to tell me what my next step should be - different manifold, different carb? Thanks! This is the one I bought: https://www.amazon.com/dp/B0BNBGPDS7 Attached Thumbnails
	0

11-04-2022, 09:53 PM	#18
Bill Hilly Join Date: Feb 2021 Posts: 958	As coincidence would have it, I just installed a PE28fl on my internally stock TBR7D. I wasn't expecting any performance gain, but Amazon had a good price, and 10 percent coupon I have been running the aftermarket CRF230 type exhaust for a while, and I was very pleased with it. It's supposed to free up a couple HP, and it did make my bike more eager to pull, and seemed like it's more comfortable at higher RPM. I was surprised,but the carb DID a little more of the same effect, but I had switched back to my stock airbox a little while back,and I now am running the foam pod filter with the Nibbi. I am running a 120 main, and 40 pilot, and it runs fantastic, not even the slightest stumble. I was running a 115/36 with the stock carb, and it ran just fine, but it just has a little more wind now. My throttle cable is a hair short, and if I turn it out enough to catch a thread on the lock ring(nut), it want to increase idle speed when I turn the handlebar, but I just taped it .I can also say that the stock airbox tube on mine wouldn't go over the back of the Nibbi https://www.ebay.com/itm/27472535351...b_b_asin_title
	0

11-04-2022, 09:58 PM	#19
Bill Hilly Join Date: Feb 2021 Posts: 958	Here is link to what I think is a good deal on the carb. I thought I put it on the last post, but it doesn't show up. https://www.amazon.com/gp/aw/d/B0B4V...b_b_asin_title
	0