jpx .28 os .28
06-11-2008, 06:51 PM
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RE: jpx .28 os .28
I have both and can say that they both have crazy bottom end but the OS seems to pull better on top. Either way, unless you are running on a big track, both engines have way more power than you will need. I should also note that both the OS and Jammin have run perfectly for me so whichever one you choose, you should be happy.
06-12-2008, 04:39 PM
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RE: jpx .28 os .28
The Jammin is a good motor but when you compare it to the OS..the OS is a better motor..but it costs more also. For me I have always thought that the OS has the best carbs..period,. The OS is easy to Tune, holds a tune and idles better than any other motor i have seen. To me the OS has way to much power for most tracks, It just over powers..throttle control is key here..but they are fun..even if you do over shoot a few turns every now and again..
..you have no problems clearing any jump..that is as long as you have traction..
..you have no problems clearing any jump..that is as long as you have traction..
06-12-2008, 05:41 PM
#4
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RE: jpx .28 os .28
I have both motors.... I have had multiple Jammin and Picco 28's and just one OS 28..........As said before both motors have killer bottom end but the OS seems to have better top end run out.... Both motor idle extremely well, the Jammin is less prone to loading up tho, not that its an issue with either motor...but the Jammin always maintains crisp trigger no matter how long it idles...... Neither motor is perfect, my OS 28 had its front bearing start leaking very badly by tank 10, the carb boot leaks and the carb base leaks.... All easily fixxed, but still not perfect......... the Jammin carbs can be leaky so sealing is IMHO mandatory....... The Jammin uses a harder piston and definitely holds its pinch much longer, the OS 28 lost its pinch somewhere around tank 10 which worries me the piston is of a softer metal.... The jammins on the other hand will carry pinch for many gallons, at gallon 6 many still will stick at TDC..... But even tho my OS 28 has no pinch it still has great compression, but for how long I am unsure, but judging by how fat it lost its pinch I suspect the engine will wear fairly quickly..Both motors use good quality steel on the cranks, OS V-Specs are known to wear crank pins but I am unsure of the OS 28...I do know the Jammin have a oversized crankpin that I have never seen wear out of round...... The Jammin will wear it connecting rod if anything, so I recomend monitoring rod slop, usually the only failure point in a Jammin is the connecting rod........
The OS has the better powerband, the Jammin is more durable, the OS is a little easier to tune, the Jammin idles better..the OS is better on fuel...... both hit very hard in the low end and too much power for 90% of users... I do not think a person could go wrong with either engine....
The OS has the better powerband, the Jammin is more durable, the OS is a little easier to tune, the Jammin idles better..the OS is better on fuel...... both hit very hard in the low end and too much power for 90% of users... I do not think a person could go wrong with either engine....
06-12-2008, 10:16 PM
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RE: jpx .28 os .28
ORIGINAL: supertib
I have both motors.... I have had multiple Jammin and Picco 28's and just one OS 28..........As said before both motors have killer bottom end but the OS seems to have better top end run out.... Both motor idle extremely well, the Jammin is less prone to loading up tho, not that its an issue with either motor...but the Jammin always maintains crisp trigger no matter how long it idles...... Neither motor is perfect, my OS 28 had its front bearing start leaking very badly by tank 10, the carb boot leaks and the carb base leaks.... All easily fixxed, but still not perfect......... the Jammin carbs can be leaky so sealing is IMHO mandatory....... The Jammin uses a harder piston and definitely holds its pinch much longer, the OS 28 lost its pinch somewhere around tank 10 which worries me the piston is of a softer metal.... The jammins on the other hand will carry pinch for many gallons, at gallon 6 many still will stick at TDC..... But even tho my OS 28 has no pinch it still has great compression, but for how long I am unsure, but judging by how fat it lost its pinch I suspect the engine will wear fairly quickly..Both motors use good quality steel on the cranks, OS V-Specs are known to wear crank pins but I am unsure of the OS 28...I do know the Jammin have a oversized crankpin that I have never seen wear out of round...... The Jammin will wear it connecting rod if anything, so I recomend monitoring rod slop, usually the only failure point in a Jammin is the connecting rod........
The OS has the better powerband, the Jammin is more durable, the OS is a little easier to tune, the Jammin idles better..the OS is better on fuel...... both hit very hard in the low end and too much power for 90% of users... I do not think a person could go wrong with either engine....
I have both motors.... I have had multiple Jammin and Picco 28's and just one OS 28..........As said before both motors have killer bottom end but the OS seems to have better top end run out.... Both motor idle extremely well, the Jammin is less prone to loading up tho, not that its an issue with either motor...but the Jammin always maintains crisp trigger no matter how long it idles...... Neither motor is perfect, my OS 28 had its front bearing start leaking very badly by tank 10, the carb boot leaks and the carb base leaks.... All easily fixxed, but still not perfect......... the Jammin carbs can be leaky so sealing is IMHO mandatory....... The Jammin uses a harder piston and definitely holds its pinch much longer, the OS 28 lost its pinch somewhere around tank 10 which worries me the piston is of a softer metal.... The jammins on the other hand will carry pinch for many gallons, at gallon 6 many still will stick at TDC..... But even tho my OS 28 has no pinch it still has great compression, but for how long I am unsure, but judging by how fat it lost its pinch I suspect the engine will wear fairly quickly..Both motors use good quality steel on the cranks, OS V-Specs are known to wear crank pins but I am unsure of the OS 28...I do know the Jammin have a oversized crankpin that I have never seen wear out of round...... The Jammin will wear it connecting rod if anything, so I recomend monitoring rod slop, usually the only failure point in a Jammin is the connecting rod........
The OS has the better powerband, the Jammin is more durable, the OS is a little easier to tune, the Jammin idles better..the OS is better on fuel...... both hit very hard in the low end and too much power for 90% of users... I do not think a person could go wrong with either engine....
06-13-2008, 03:50 AM
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RE: jpx .28 os .28
I've got about 4 1/2 gallon or so on my OS .28
It lost it's mechanical pinch around 2 gallon or so, just like every OS engine I have.
Granted, my XZ has been modded, but he didn't do anything to help or hurt the pinch.
The OS motors don't have a ton of pinch from the factory.
They do however have excellent compression, even when hot, and that is what counts.
My XZ and my Speed motor are insane fast and a blast to drive.
I don't see myself buying anything else besides OS motors.
They have their quirks, but overall, I'm happy with them.
Scott
It lost it's mechanical pinch around 2 gallon or so, just like every OS engine I have.
Granted, my XZ has been modded, but he didn't do anything to help or hurt the pinch.
The OS motors don't have a ton of pinch from the factory.
They do however have excellent compression, even when hot, and that is what counts.
My XZ and my Speed motor are insane fast and a blast to drive.
I don't see myself buying anything else besides OS motors.
They have their quirks, but overall, I'm happy with them.
Scott
