Cam for a pentora 250

J0SH122 · 03-07-2021, 09:41 PM

So I’ve been looking everywhere for a cam for my pentora 250 but cant seem to find anything on it.I’m trying to put a cam on it because I’m trying to squeeze out some extra horses out of it.The main reason I cant find anything because mine is a over head cam or ohc and most Chinese 250 are push rod.If anybody know anything please let me know where I can buy a cam for it

Thanks

**JerryHawk250** · 03-08-2021, 08:51 AM

The Wiseco 11:1 piston for the Honda CRF230F will fit and so will cams for the Honda CRF230F.
Cams
https://www.ebay.com/itm/UPGRADE-Cam...9/174322962671
https://www.ebay.com/itm/New-Hot-Cam....c101195.m1851
https://www.ebay.com/itm/BBR-Motorsp....c101195.m1851
Piston
https://www.ebay.com/itm/Wiseco-4816...F/382670730611

J0SH122 · 03-08-2021, 05:25 PM

Thanks so much I will order the cam and piston for it right away and how much power can I hope to gain by doing these mods

**JerryHawk250** · 03-08-2021, 10:15 PM

Good for 5 to 7 hp. Definitely made a huge difference on my X22R 250. Also porting the head and a 30mm smooth bore carb will add some hp.

J0SH122 · 03-09-2021, 02:36 PM

Is there a stage 2 or stage 3 cam available or is it only a stage 1 available? and also where can I buy the smooth bore carb

franque · 03-09-2021, 02:56 PM

Stages are just marketing terms, there are no fixed or set definitions... If you get a big cam, you might need stiffer valve springs, clearance the valve pockets in the piston, lightweight retainers, etc. Just to theoretically make it all work together physically, and then supporting mods like a different carb, exhaust, ported head and a high compression piston so that it will run well together.

If you're thinking in terms of stages, it might be best to start small and understand what you're doing first.

**JerryHawk250** · 03-09-2021, 02:59 PM

Quote:

Originally Posted by franque

Stages are just marketing terms, there are no fixed or set definitions... If you get a big cam, you might need stiffer valve springs, clearance the valve pockets in the piston, lightweight retainers, etc. Just to theoretically make it all work together physically, and then supporting mods like a different carb, exhaust, ported head and a high compression piston so that it will run well together.

If you're thinking in terms of stages, it might be best to start small and understand what you're doing first.

^^ What he said ^^ The stage 1 cam can use stock valve springs and so can the Upgrade cam i had linked. Not sure on the BBR cam .

J0SH122 · 03-09-2021, 04:58 PM

I understand what u mean and also will removing the egr valve help with horse power on nah

**JerryHawk250** · 03-09-2021, 05:09 PM

Quote:

Originally Posted by J0SH122

I understand what u mean and also will removing the egr valve help with horse power on nah

Nah, won't make any difference.

J0SH122 · 03-11-2021, 12:45 AM

One question will a 420 sprocket fit a 520 chain or is it not possible?and thanks for all the help

J0SH122 · 03-11-2021, 07:22 PM

Ok so I took out the front sprocket and put a new one I bought and I found out it didn’t fit so I but everything back together but now my bike is running very weird for example I was out and It was sputtering when i shift like when you shift bad but I was shifting good and was still doing it but when I put the Choke on it runs fine and this is the first time doing this did I install something wrong on the atv when I put everything back together
Any idea will help because I been looking at it and I didn’t move anything on it maybe I installed the front sprocket wrong or did I ruin something in the transmission when I was tightening the front sprocket

**JerryHawk250** · 03-11-2021, 08:11 PM

Quote:

Originally Posted by J0SH122

One question will a 420 sprocket fit a 520 chain or is it not possible?and thanks for all the help

No it will not

**JerryHawk250** · 03-11-2021, 08:14 PM

Sounds like you were trying to run with the choke on. Messing with the sprocket has nothing to do with the carb.

J0SH122 · 03-11-2021, 11:23 PM

Thanks and also I cleaned my carb just to be sure but when i was putting my intake boot on I noticed that when I tightened the clamp the boot would fold in one place creating like a little hole Like if the boot was too big is this normal and can I mess up my engine running it like this

**JerryHawk250** · 03-12-2021, 08:34 AM

If it's on the engine side of the carb then yes that can cause some issues. If on the filter side it could make the engine run a little leaner as it's getting more air. A leak on either side will cause it to run lean and cut out. Like most of the china bikes they come tune real lean to pass the epa certifications. I would get a jet kit and try a larger jet.

03-07-2021, 09:41 PM	#1
J0SH122 Join Date: Mar 2021 Posts: 21	Cam for a pentora 250 So I’ve been looking everywhere for a cam for my pentora 250 but cant seem to find anything on it.I’m trying to put a cam on it because I’m trying to squeeze out some extra horses out of it.The main reason I cant find anything because mine is a over head cam or ohc and most Chinese 250 are push rod.If anybody know anything please let me know where I can buy a cam for it Thanks
	0

03-08-2021, 08:51 AM	#2
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,725	The Wiseco 11:1 piston for the Honda CRF230F will fit and so will cams for the Honda CRF230F. Cams https://www.ebay.com/itm/UPGRADE-Cam...9/174322962671 https://www.ebay.com/itm/New-Hot-Cam....c101195.m1851 https://www.ebay.com/itm/BBR-Motorsp....c101195.m1851 Piston https://www.ebay.com/itm/Wiseco-4816...F/382670730611 __________________ 2024 Linhai 300 ATV 4x4 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 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

03-08-2021, 10:15 PM	#4
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,725	Good for 5 to 7 hp. Definitely made a huge difference on my X22R 250. Also porting the head and a 30mm smooth bore carb will add some hp. __________________ 2024 Linhai 300 ATV 4x4 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 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

03-11-2021, 08:14 PM	#13
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,725	Sounds like you were trying to run with the choke on. Messing with the sprocket has nothing to do with the carb. __________________ 2024 Linhai 300 ATV 4x4 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 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

03-12-2021, 08:34 AM	#15
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,725	If it's on the engine side of the carb then yes that can cause some issues. If on the filter side it could make the engine run a little leaner as it's getting more air. A leak on either side will cause it to run lean and cut out. Like most of the china bikes they come tune real lean to pass the epa certifications. I would get a jet kit and try a larger jet. __________________ 2024 Linhai 300 ATV 4x4 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 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

03-08-2021, 05:25 PM	#3
J0SH122 Join Date: Mar 2021 Posts: 21	Thanks so much I will order the cam and piston for it right away and how much power can I hope to gain by doing these mods
	0

03-09-2021, 02:36 PM	#5
J0SH122 Join Date: Mar 2021 Posts: 21	Is there a stage 2 or stage 3 cam available or is it only a stage 1 available? and also where can I buy the smooth bore carb
	0

03-09-2021, 02:56 PM	#6
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	Stages are just marketing terms, there are no fixed or set definitions... If you get a big cam, you might need stiffer valve springs, clearance the valve pockets in the piston, lightweight retainers, etc. Just to theoretically make it all work together physically, and then supporting mods like a different carb, exhaust, ported head and a high compression piston so that it will run well together. If you're thinking in terms of stages, it might be best to start small and understand what you're doing first.
	1

03-09-2021, 04:58 PM	#8
J0SH122 Join Date: Mar 2021 Posts: 21	I understand what u mean and also will removing the egr valve help with horse power on nah
	0

03-11-2021, 12:45 AM	#10
J0SH122 Join Date: Mar 2021 Posts: 21	One question will a 420 sprocket fit a 520 chain or is it not possible?and thanks for all the help
	0

03-11-2021, 07:22 PM	#11
J0SH122 Join Date: Mar 2021 Posts: 21	Ok so I took out the front sprocket and put a new one I bought and I found out it didn’t fit so I but everything back together but now my bike is running very weird for example I was out and It was sputtering when i shift like when you shift bad but I was shifting good and was still doing it but when I put the Choke on it runs fine and this is the first time doing this did I install something wrong on the atv when I put everything back together Any idea will help because I been looking at it and I didn’t move anything on it maybe I installed the front sprocket wrong or did I ruin something in the transmission when I was tightening the front sprocket
	0

03-11-2021, 11:23 PM	#14
J0SH122 Join Date: Mar 2021 Posts: 21	Thanks and also I cleaned my carb just to be sure but when i was putting my intake boot on I noticed that when I tightened the clamp the boot would fold in one place creating like a little hole Like if the boot was too big is this normal and can I mess up my engine running it like this
	0