TBR7 with PWK carb needing help

twinmonkeys · 07-26-2020, 09:47 PM

Hello all I am in Northeast North Carolina and new to the site. I have been lurking and learning for a couple of years . I purchased a TBR7 in April and done after market exhaust, and pod filter with a PWK 30mm carb and oil cooler.

The bike has 700 miles on it and was OK since changing the carb. Problem I am having is dialing it in. I have had OK luck with 130 main, 35 pilot and needle on 1 up from middle. It will pull hard to 6000 and then starts pissing and popping. I have gone up with main jets down with main jets same with the needle and pilot doing 1 adjustment at a time and seeing how it works out.

If I go higher then the above setting the bike misses farts, fouls plugs and can't be ridden. With the setting I have a plug that is white and no coffee or coco color to it. I am worried about it being to lean.

It is also a little hard to figure out since in the morning it can be 70 out and by the time to head home it maybe 95 with 90 percent humidity.

Thanks in advance for any and all help.

**JerryHawk250** · 07-27-2020, 08:05 AM

I would say that it's running too rich. I was running the PWK30 on my Hawk which the head has been ported and decked and running 10:1 compression ratio. A 125 main and 38 pilot is what i was running. I would say a 120 main would probably be close.

twinmonkeys · 07-27-2020, 08:54 AM

Thanks JerryHawk I reread my post and I forgot to mention I am at sea level literally. I am also running the NGK irridiam plug The thing is I have done the engine chop and with the 130 MJ, 35 pj setting and the plug is white on the porcelain no discoloration at all. But I am willing to try anything. Could the carb be a little to big also.

Wild Dog · 07-27-2020, 09:37 AM

That size is OK for the CG230, but you will find that the PWK can be a little b"""" to jet correctly even more the chinese ones.

Did you chop the engine?

twinmonkeys · 07-27-2020, 09:51 AM

Yes I did the chop test it is what we call it when you shut the engine off at a given rpm after running it at given rpm under load. I did it at 4000,5000,6000 to get a plug reading. Couldn't do any higher RPM since won't turn above 6000. I never had this much problem tuning a carb even my dual carbs on my VW were easier then this hing is.

Wild Dog · 07-27-2020, 10:09 AM

Quote:

Originally Posted by twinmonkeys

Yes I did the chop test it is what we call it when you shut the engine off at a given rpm after running it at given rpm under load. I did it at 4000,5000,6000 to get a plug reading. Couldn't do any higher RPM since won't turn above 6000. I never had this much problem tuning a carb even my dual carbs on my VW were easier then this hing is.

Oh here we call it plug chop, anyway, those PWK are annoying to jet.
Is the power jet working? Maybe that could be the issue you have at 6000 rpm and up.

franque · 07-27-2020, 10:11 AM

See if it's better or worse without the air filter. If better, you're too rich, if worse, too lean. Or you could flip the choke on and the reverse is true.

twinmonkeys · 07-27-2020, 10:25 AM

Wild dog not sure about the power jet working can check that out tonight after work. Will need something to destress since I am a nurse at a pediatric Covid clinic.

Franque have tried no filter and filter just to see if makes a different and it did not. I run a pod filter so pretty free flowing.

franque · 07-27-2020, 01:01 PM

Try the choke test then. How's the exhaust side? Any leaks, everything tight?

twinmonkeys · 07-27-2020, 01:18 PM

Frangue, will try choke test tonight also with checking the power jet. Exhaust is good no leaks and all is tight.

twinmonkeys · 07-27-2020, 10:00 PM

Figured I would let you all know how it went. I cleaned the power jet out just to make sure it was good Wild Dog. JerryHawk I put the jetting in you suggested. I changed the factory fuel line to new and rerouted it a little. It fired right up and idled at 1500 nice and steady. It the throttle to make sure the power jet was working and it was working fine.

On went the brain bucket and went for a rip. I am pleased to say that the bike turned 8000 in first 3 gears 4th and 5th was good. No popping out the exhaust running down the road. I think the bike actually ran smoother not so bad on vibrations. Bike hit 74 per the digital speedo with me laying on the tank. It ran 69 with me in normal riding position. Not bad for a 240lb 5'9" old guy it will work just fine.

Thank you gentlemen very much, now I won't need to worry until temps get below 70 all the time to rejet. I will pick brains again then if I need assistance. I figure it will be maybe the 132.5 or 135 mj then, not sure about pilot and needle.

Wild Dog · 07-28-2020, 10:33 AM

Quote:

Originally Posted by twinmonkeys

Figured I would let you all know how it went. I cleaned the power jet out just to make sure it was good Wild Dog. JerryHawk I put the jetting in you suggested. I changed the factory fuel line to new and rerouted it a little. It fired right up and idled at 1500 nice and steady. It the throttle to make sure the power jet was working and it was working fine.

On went the brain bucket and went for a rip. I am pleased to say that the bike turned 8000 in first 3 gears 4th and 5th was good. No popping out the exhaust running down the road. I think the bike actually ran smoother not so bad on vibrations. Bike hit 74 per the digital speedo with me laying on the tank. It ran 69 with me in normal riding position. Not bad for a 240lb 5'9" old guy it will work just fine.

Thank you gentlemen very much, now I won't need to worry until temps get below 70 all the time to rejet. I will pick brains again then if I need assistance. I figure it will be maybe the 132.5 or 135 mj then, not sure about pilot and needle.

That's great, sometimes some details that seems "small" like rerouting a gas line can make a difference.

twinmonkeys · 07-28-2020, 11:42 AM

Exactly Wild Dog, not sure what part of the solution actually fixed the problem. The only thing that matters is it is fixed, and again thanks.

07-26-2020, 09:47 PM	#1
twinmonkeys Join Date: May 2020 Location: North Carolina Posts: 11	TBR7 with PWK carb needing help Hello all I am in Northeast North Carolina and new to the site. I have been lurking and learning for a couple of years . I purchased a TBR7 in April and done after market exhaust, and pod filter with a PWK 30mm carb and oil cooler. The bike has 700 miles on it and was OK since changing the carb. Problem I am having is dialing it in. I have had OK luck with 130 main, 35 pilot and needle on 1 up from middle. It will pull hard to 6000 and then starts pissing and popping. I have gone up with main jets down with main jets same with the needle and pilot doing 1 adjustment at a time and seeing how it works out. If I go higher then the above setting the bike misses farts, fouls plugs and can't be ridden. With the setting I have a plug that is white and no coffee or coco color to it. I am worried about it being to lean. It is also a little hard to figure out since in the morning it can be 70 out and by the time to head home it maybe 95 with 90 percent humidity. Thanks in advance for any and all help.
	0

07-27-2020, 08:05 AM	#2
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,574	I would say that it's running too rich. I was running the PWK30 on my Hawk which the head has been ported and decked and running 10:1 compression ratio. A 125 main and 38 pilot is what i was running. I would say a 120 main would probably be close. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	0

07-27-2020, 08:54 AM	#3
twinmonkeys Join Date: May 2020 Location: North Carolina Posts: 11	Thanks JerryHawk I reread my post and I forgot to mention I am at sea level literally. I am also running the NGK irridiam plug The thing is I have done the engine chop and with the 130 MJ, 35 pj setting and the plug is white on the porcelain no discoloration at all. But I am willing to try anything. Could the carb be a little to big also.
	0

07-27-2020, 09:37 AM	#4
Wild Dog Join Date: Dec 2016 Location: Argentina Posts: 756	That size is OK for the CG230, but you will find that the PWK can be a little b"""" to jet correctly even more the chinese ones. Did you chop the engine?
	0

07-27-2020, 09:51 AM	#5
twinmonkeys Join Date: May 2020 Location: North Carolina Posts: 11	Yes I did the chop test it is what we call it when you shut the engine off at a given rpm after running it at given rpm under load. I did it at 4000,5000,6000 to get a plug reading. Couldn't do any higher RPM since won't turn above 6000. I never had this much problem tuning a carb even my dual carbs on my VW were easier then this hing is.
	0

07-27-2020, 10:11 AM	#7
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	See if it's better or worse without the air filter. If better, you're too rich, if worse, too lean. Or you could flip the choke on and the reverse is true.
	0

07-27-2020, 10:25 AM	#8
twinmonkeys Join Date: May 2020 Location: North Carolina Posts: 11	Wild dog not sure about the power jet working can check that out tonight after work. Will need something to destress since I am a nurse at a pediatric Covid clinic. Franque have tried no filter and filter just to see if makes a different and it did not. I run a pod filter so pretty free flowing.
	0

07-27-2020, 01:01 PM	#9
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	Try the choke test then. How's the exhaust side? Any leaks, everything tight?
	0

07-27-2020, 01:18 PM	#10
twinmonkeys Join Date: May 2020 Location: North Carolina Posts: 11	Frangue, will try choke test tonight also with checking the power jet. Exhaust is good no leaks and all is tight.
	0

07-27-2020, 10:00 PM	#11
twinmonkeys Join Date: May 2020 Location: North Carolina Posts: 11	Figured I would let you all know how it went. I cleaned the power jet out just to make sure it was good Wild Dog. JerryHawk I put the jetting in you suggested. I changed the factory fuel line to new and rerouted it a little. It fired right up and idled at 1500 nice and steady. It the throttle to make sure the power jet was working and it was working fine. On went the brain bucket and went for a rip. I am pleased to say that the bike turned 8000 in first 3 gears 4th and 5th was good. No popping out the exhaust running down the road. I think the bike actually ran smoother not so bad on vibrations. Bike hit 74 per the digital speedo with me laying on the tank. It ran 69 with me in normal riding position. Not bad for a 240lb 5'9" old guy it will work just fine. Thank you gentlemen very much, now I won't need to worry until temps get below 70 all the time to rejet. I will pick brains again then if I need assistance. I figure it will be maybe the 132.5 or 135 mj then, not sure about pilot and needle.
	2

07-28-2020, 11:42 AM	#13
twinmonkeys Join Date: May 2020 Location: North Carolina Posts: 11	Exactly Wild Dog, not sure what part of the solution actually fixed the problem. The only thing that matters is it is fixed, and again thanks.
	0