Late 2021 TBR7 manufacturing problems - Page 2

Thumper · 03-21-2022, 01:42 PM

Quote:

Originally Posted by Nospark

I have adjustableneedle set 4th notch down out of 5. I can move it down to last notch.

OH! Already on the 4th position and still stumbling off idle. Maybe the 38 isn't enough for your setup. Worth a try, but you will probably end up increasing pilot jet size to solve this. I don't think the main jet can be involved until maybe 3/4 throttle. Is the fuel screw out to ~3 turns? You are working with OEM PZ carb right?

Nospark · 03-22-2022, 06:52 PM

I purchased a new PZ30 clone so I wouldn't have to slot screws and ship needle. It seems identical to the one that came on the bike. I'm thinking the fuel screw is 2 turns out. I'm sure it's not 3. I may be able to turn fuel screw out to 3 without removing the carb so it sounds like you're suggesting I could try that first before removing and changing jets?

alex_in_az · 03-22-2022, 07:55 PM

crap like this is why I had txpowersports do pdi on mine

Nospark · 03-22-2022, 10:34 PM

Nothing wrong with having the wholesaler assemble your bike. They do it all the time so, they should be good at it.

Thumper · 03-25-2022, 08:35 AM

I could be wrong on the pilot jetting. We bumped to #38 on my son's TBR7, but only 2.5 turns out. It seems OK, but haven't driven it more than a minute (still haven't welded the footpeg back on.

I mean, you might be on the rich side now. We are at ~same elevation (I believe we are at 700ft). The carb will get a lot more scrutiny once the bike is fully assembled, running more hours,

Nospark · 03-25-2022, 12:22 PM

Thumper, Thx. Let's keep in touch on the carb adjustments since we have the same bikes @ same elevation, sharing info on jets and tuning will be helpful. Hopefully the weather this weekend here in Milwaukee will provide an opportunity for me to spend some more time on it.

willardnigma · 03-27-2022, 03:56 AM

I skipped the airbox entirely by just using a pod filter on my carb. Easier to swap the filter or clean it when it gets dirty. I do recommend sealing the airbox back up if you do as it does also send oil into it from the pc valve

https://www.amazon.com/HIAORS-Angled..._d_rp_1_t&th=1

MAKE SURE TO MATCH THE SIZE WITH YOUR CARB

buzz · 03-27-2022, 12:17 PM

Stock carb and a 45 jet a pipe and happy

Nospark · 03-28-2022, 09:38 AM

Wasn't able to get back to the bike this weekend. Way cold. We'll see about next weekend

kyle · 04-01-2022, 11:01 AM

My vote is bigger pilot.

Megadan · 04-01-2022, 01:11 PM

Just to toss this out there for the whole carb tuning conversation. While the bike is breaking in, the carb tuning is going to be harder to judge due to the rings not sealing quite as good.

Also, do yourself a favor and don't make too many adjustments at the same time. You are stacking variables that all intersect, which makes it REALLY hard to judge what adjustment did what. One thing at a time will net the best results.

All carb tuning should also be done with the engine at operating temps. Being ridden for at LEAST 5 minutes or so.

Here is my order of operations as far as carb tuning goes.
1. Idle Mixture.
2. Pilot Jet.
3. Main jet.
4. Needle

On an otherwise unmodded CG, using actual Keihin jets a 35 pilot jet is usually sufficient in most cases and the 38 may be a bit rich on an unmodded bike. By actual Keihin jets, I am excluding the jets that have the K next to the number, like the K40 found in the Hawks. I have found that these jet sizes don't directly correlate to the Keihin sizes and use their own scale.

I would recommend putting the needle in the 3rd slot. It wont lean it out enough to be dangerous, and the needle is honestly the last thing that should be adjusted, and in my experience often doesn't need to leave that 3rd slot once the pilot and main are sized correctly.

While the pilot jet does affect the idle mixture in terns of how far in or out the adjustment needs to be, they are also still operating separately. You need to find the proper adjustment for the idle mixture using the idle drop method with the engine at operating temp, and once you know the idle mixture is dialed in then you can judge the pilot jet size.

The idle drop method is straight forward, but adjusting the PZ carburetors idle mixture is a royal PITA, which is why I love the PE carbs so much lol. If you are lucky and the idle mixture screw on your PZ protrudes down out of the carb body, you can put a length of fuel hose on it that allows you to turn it with your fingers. The idea is to start with the idle mixture at 1.5 turns out from lightly seated and have the idle speed bumped up a little (1700ish rpm). Turn the screw out 1/4 turn at a time to richen the mixture until the idle drops and back off 1/4 turn ( keep track of how many 1/4 turns it may have taken) This would be the "rich" limit. Next turn the screw in 1/4 turn at a time and blip the throttle after each adjustment. Once the bike starts to hesitate or the engine doesn't settle quickly back to idle, or hangs, back it out 1/4 turn. This would be the lean limit. From there, if you want to split the difference of the two you will likely be in a decent spot.

I personally judge where to leave my idle mixture on two factors. Steady idle, and hot restarts. If the idle mixture is too rich the bike will sometimes struggle to restart when hot. If the idle has small surges and dips after sitting at idle for 15 or so seconds, it's also likely a bit rich.

In either case, if the mixture screw requires being turned out more than 2.5 turns, or in less than 1 turn before it seats, you need to change pilot jets. Too far out means you need to go bigger. Less than 1 in, smaller.

Judging the pilot jet size is really simple. Ride the bike on a flat road and hold a steady light throttle (no more than 1/8th turn out). I find that 20ish mph in second or third gear works great for this. If it hesitates or bucks at all the sizing is off. You can use your idle mixture setting to actually help determine if it is too rich or lean. If that idle mixture is barely 1 turn out, likely too rich. If it's over 2 out, likely on the lean side.

Once that's sorted, figure out your main jet. Why? Because like the pilot, the throttle position it influences the most is easy to find and judge. It also affects the needle fueling. Once you know your main is good, IF you have any sort of hiccups or other odd fueling issues in the middle of the throttle sweep (between 1/4 or 3/4 trottle), THEN adjust the needle position.

Ol,fart · 04-02-2022, 04:12 AM

My intake pipe was about 1/3 closed on 2021 hawk . I pushed a tailhousing bushing for a ford AOD/C4 transmission down the tube from the carb side. Worked perfect.

Nospark · 04-04-2022, 04:32 PM

Megadan, thx for the carb turning help. I'm still waiting for the weather here in Milwaukee to break so I can get the bike out and attack the carb using what's been shared.
I often wonder what my life would be like if I lived in a place where I could use my toys year round.

Captain ThirdGen · 07-05-2022, 05:28 PM

Hello, first post. Just got a TBR7 from Tx Powersports, labeled as a 2021 model according to the plaque on swingarm...

Mine also has the "rogue green ground wire", anyone ever figure out where it goes?

My bike has rear turn signals, horn, etc. But front turn signals and starter switch wont work

The starter switch is "soft" ie, no feedback, click etc. I suspect these issues trace back to this ground wire needing a home

Thumper · 07-05-2022, 05:29 PM

The list was pretty long on issues with my son's TBR7.
I had to bend the engine guard and grind the mounting holes to fit. The rack had the mounting pieces welded way off, and was difficult to mount without the proper hardware, only after using a drill to grind the mounting posts to fit close enough to get the screws started. But this left footpeg was just pitiful. It broke off the first time my son got on the bike:

I ground off the paint on the rear stay to connect the welder ground lead, and ground of the paint and bad welding on the footpeg mount, and the footpeg post on the frame. What a mess. Cleaning up and repainting took more time after getting it welded back on. Tao made a real bad impression with me.

All of this made this bike a mistake.

03-22-2022, 06:52 PM	#17
Nospark Join Date: Jan 2022 Location: Milwaukee, WI Posts: 167	I purchased a new PZ30 clone so I wouldn't have to slot screws and ship needle. It seems identical to the one that came on the bike. I'm thinking the fuel screw is 2 turns out. I'm sure it's not 3. I may be able to turn fuel screw out to 3 without removing the carb so it sounds like you're suggesting I could try that first before removing and changing jets? __________________ 2021 TBR7D 17 front, 42 rear PZ30 Clone Milwaukee, WI
	0

03-22-2022, 07:55 PM	#18
alex_in_az Join Date: Aug 2013 Location: Goodyear, Arizona Posts: 412	crap like this is why I had txpowersports do pdi on mine __________________ 2020 Tao TBR7 9.3:1 PnP head CRF230F exhaust 4 degree advance key 290 degree cam Nibbi PE30 and cone filter Front fork brace
	0

03-22-2022, 10:34 PM	#19
Nospark Join Date: Jan 2022 Location: Milwaukee, WI Posts: 167	Nothing wrong with having the wholesaler assemble your bike. They do it all the time so, they should be good at it. __________________ 2021 TBR7D 17 front, 42 rear PZ30 Clone Milwaukee, WI
	0

03-25-2022, 12:22 PM	#21
Nospark Join Date: Jan 2022 Location: Milwaukee, WI Posts: 167	Thumper, Thx. Let's keep in touch on the carb adjustments since we have the same bikes @ same elevation, sharing info on jets and tuning will be helpful. Hopefully the weather this weekend here in Milwaukee will provide an opportunity for me to spend some more time on it. __________________ 2021 TBR7D 17 front, 42 rear PZ30 Clone Milwaukee, WI
	0

03-28-2022, 09:38 AM	#24
Nospark Join Date: Jan 2022 Location: Milwaukee, WI Posts: 167	Wasn't able to get back to the bike this weekend. Way cold. We'll see about next weekend __________________ 2021 TBR7D 17 front, 42 rear PZ30 Clone Milwaukee, WI
	0

03-25-2022, 08:35 AM	#20
Thumper Join Date: Feb 2021 Location: Kansas City Posts: 2,733	I could be wrong on the pilot jetting. We bumped to #38 on my son's TBR7, but only 2.5 turns out. It seems OK, but haven't driven it more than a minute (still haven't welded the footpeg back on. I mean, you might be on the rich side now. We are at ~same elevation (I believe we are at 700ft). The carb will get a lot more scrutiny once the bike is fully assembled, running more hours,
	0

03-27-2022, 03:56 AM	#22
willardnigma Join Date: Apr 2020 Location: Ohio Posts: 52	I skipped the airbox entirely by just using a pod filter on my carb. Easier to swap the filter or clean it when it gets dirty. I do recommend sealing the airbox back up if you do as it does also send oil into it from the pc valve https://www.amazon.com/HIAORS-Angled..._d_rp_1_t&th=1 MAKE SURE TO MATCH THE SIZE WITH YOUR CARB
	0

03-27-2022, 12:17 PM	#23
buzz Join Date: Dec 2020 Location: Dayton Pa. Posts: 953	Stock carb and a 45 jet a pipe and happy
	0

04-01-2022, 11:01 AM	#25
kyle Join Date: Jun 2021 Posts: 110	My vote is bigger pilot.
	0

04-01-2022, 01:11 PM	#26
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,110	Just to toss this out there for the whole carb tuning conversation. While the bike is breaking in, the carb tuning is going to be harder to judge due to the rings not sealing quite as good. Also, do yourself a favor and don't make too many adjustments at the same time. You are stacking variables that all intersect, which makes it REALLY hard to judge what adjustment did what. One thing at a time will net the best results. All carb tuning should also be done with the engine at operating temps. Being ridden for at LEAST 5 minutes or so. Here is my order of operations as far as carb tuning goes. 1. Idle Mixture. 2. Pilot Jet. 3. Main jet. 4. Needle On an otherwise unmodded CG, using actual Keihin jets a 35 pilot jet is usually sufficient in most cases and the 38 may be a bit rich on an unmodded bike. By actual Keihin jets, I am excluding the jets that have the K next to the number, like the K40 found in the Hawks. I have found that these jet sizes don't directly correlate to the Keihin sizes and use their own scale. I would recommend putting the needle in the 3rd slot. It wont lean it out enough to be dangerous, and the needle is honestly the last thing that should be adjusted, and in my experience often doesn't need to leave that 3rd slot once the pilot and main are sized correctly. While the pilot jet does affect the idle mixture in terns of how far in or out the adjustment needs to be, they are also still operating separately. You need to find the proper adjustment for the idle mixture using the idle drop method with the engine at operating temp, and once you know the idle mixture is dialed in then you can judge the pilot jet size. The idle drop method is straight forward, but adjusting the PZ carburetors idle mixture is a royal PITA, which is why I love the PE carbs so much lol. If you are lucky and the idle mixture screw on your PZ protrudes down out of the carb body, you can put a length of fuel hose on it that allows you to turn it with your fingers. The idea is to start with the idle mixture at 1.5 turns out from lightly seated and have the idle speed bumped up a little (1700ish rpm). Turn the screw out 1/4 turn at a time to richen the mixture until the idle drops and back off 1/4 turn ( keep track of how many 1/4 turns it may have taken) This would be the "rich" limit. Next turn the screw in 1/4 turn at a time and blip the throttle after each adjustment. Once the bike starts to hesitate or the engine doesn't settle quickly back to idle, or hangs, back it out 1/4 turn. This would be the lean limit. From there, if you want to split the difference of the two you will likely be in a decent spot. I personally judge where to leave my idle mixture on two factors. Steady idle, and hot restarts. If the idle mixture is too rich the bike will sometimes struggle to restart when hot. If the idle has small surges and dips after sitting at idle for 15 or so seconds, it's also likely a bit rich. In either case, if the mixture screw requires being turned out more than 2.5 turns, or in less than 1 turn before it seats, you need to change pilot jets. Too far out means you need to go bigger. Less than 1 in, smaller. Judging the pilot jet size is really simple. Ride the bike on a flat road and hold a steady light throttle (no more than 1/8th turn out). I find that 20ish mph in second or third gear works great for this. If it hesitates or bucks at all the sizing is off. You can use your idle mixture setting to actually help determine if it is too rich or lean. If that idle mixture is barely 1 turn out, likely too rich. If it's over 2 out, likely on the lean side. Once that's sorted, figure out your main jet. Why? Because like the pilot, the throttle position it influences the most is easy to find and judge. It also affects the needle fueling. Once you know your main is good, IF you have any sort of hiccups or other odd fueling issues in the middle of the throttle sweep (between 1/4 or 3/4 trottle), THEN adjust the needle position. __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	1

04-02-2022, 04:12 AM	#27
Ol,fart Join Date: Jan 2022 Location: Gatesville Texas Posts: 161	My intake pipe was about 1/3 closed on 2021 hawk . I pushed a tailhousing bushing for a ford AOD/C4 transmission down the tube from the carb side. Worked perfect. __________________ 2021 RPS Hawk "IKEA" (Came in a box with no instructions) 110 main jet 1washer,2.5 sprockets and the cat fell off( with a little help) 1984 Honda V65 Magna "Daddy's Little Monster" To whoever stole my anti-depressants. I Hope Your Happy !
	0

04-04-2022, 04:32 PM	#28
Nospark Join Date: Jan 2022 Location: Milwaukee, WI Posts: 167	Megadan, thx for the carb turning help. I'm still waiting for the weather here in Milwaukee to break so I can get the bike out and attack the carb using what's been shared. I often wonder what my life would be like if I lived in a place where I could use my toys year round. __________________ 2021 TBR7D 17 front, 42 rear PZ30 Clone Milwaukee, WI
	0

07-05-2022, 05:28 PM	#29
Captain ThirdGen Join Date: Jul 2022 Location: Detroit, Michigan Posts: 10	Hello, first post. Just got a TBR7 from Tx Powersports, labeled as a 2021 model according to the plaque on swingarm... Mine also has the "rogue green ground wire", anyone ever figure out where it goes? My bike has rear turn signals, horn, etc. But front turn signals and starter switch wont work The starter switch is "soft" ie, no feedback, click etc. I suspect these issues trace back to this ground wire needing a home
	0

07-05-2022, 05:29 PM	#30
Thumper Join Date: Feb 2021 Location: Kansas City Posts: 2,733	Rack miswelded, engine guard needed bending, mods, and the footpeg! The list was pretty long on issues with my son's TBR7. I had to bend the engine guard and grind the mounting holes to fit. The rack had the mounting pieces welded way off, and was difficult to mount without the proper hardware, only after using a drill to grind the mounting posts to fit close enough to get the screws started. But this left footpeg was just pitiful. It broke off the first time my son got on the bike: I ground off the paint on the rear stay to connect the welder ground lead, and ground of the paint and bad welding on the footpeg mount, and the footpeg post on the frame. What a mess. Cleaning up and repainting took more time after getting it welded back on. Tao made a real bad impression with me. All of this made this bike a mistake.
	0