Pampera carb swap to 28 PWK?

[ArmPump]

I have a line on a new cheap 28mm PWK to swap out the crazy carb that came stock on the Mrs' Pampera. But I look at the dimensions on Sudco's site and notice these discrepancies:

The PWK is shorter by 7mm from intake to outlet.
The outlet on the PWK is 1mm smaller (I figured no big deal on this one).
The intake on the PWK is 5mm larger than the DelOrto.

I probably can make the length differences work but the intake outer diameter is what worries me. Do I bust out the heatgun?

Essentially it's a 280TXT engine, but the stock carb supposedly had another jet installed by the factory that's supposed to make it a better-for-trails engine. That makes it that much harder to figure out and jet correctly, especially since I've pretty familiar with the PWK carbs.

Your input is appreciated in advance.

[GMP]

Interesting project. If my wife rode her 250 Pamp more than a couple times a year I'd be more motivated to modify it. As it is now the Dellorto works fine, its a one kick starter too.

What bugs me is the trials airbox (if you can call it that) and the flat filter that your never sure of sealing. I always wanted to swap an EC airbox, or something else that would fit. Perhaps take your carb swap to the next level and do both. Maybe something from a mini that uses the same or close in size carb, that the airboot would fit eaisily, then make some custom brackets to hold it to the frame. Spigot angle would have to be close too.

To work with what you have, the spigot OD can be built up with a small section(s) of rubber bicycle innertube bands. I've done this and it works good. 5mm larger bell OD is a bit of a stretch. I'd start by going to an autoparts store and seeing what size exhaust couplers/reducers are available that could be used to make an intake bell reducer. This would also address the potential length issue.

Good luck and keep me posted!

[ArmPump]

Originally Posted by GMP

Interesting project. If my wife rode her 250 Pamp more than a couple times a year I'd be more motivated to modify it. As it is now the Dellorto works fine, its a one kick starter too.

What bugs me is the trials airbox (if you can call it that) and the flat filter that your never sure of sealing. I always wanted to swap an EC airbox, or something else that would fit. Perhaps take your carb swap to the next level and do both. Maybe something from a mini that uses the same or close in size carb, that the airboot would fit eaisily, then make some custom brackets to hold it to the frame. Spigot angle would have to be close too.

To work with what you have, the spigot OD can be built up with a small section(s) of rubber bicycle innertube bands. I've done this and it works good. 5mm larger bell OD is a bit of a stretch. I'd start by going to an autoparts store and seeing what size exhaust couplers/reducers are available that could be used to make an intake bell reducer. This would also address the potential length issue.

Good luck and keep me posted!

I hear you on the airfilter sealing. Maybe a K&N filter would clean the air good enough and ensure a better seal, but I'm not a big fan of K&Ns in a dirtbike.

I'll let you know how it goes.

[webmaster]

I would contact rising sun imports to talk to them about what you are planning to do. GasGas made a kit to swap to the keihin for that motor - I believe it included a new carb insulator (front mount). They will also have jetting specs.

jeff

[slocalspode]

Try contacting group member "Woodschick" Tami. I know she had
this mod done on her Pampera.
You also might try contacting list member "Loosenut" Mike. I
think he may have made that change to his wife's Pamp also.
Good luck with Rising Sun, Jim Snell. Last time I tried to ask
him a question I was greeted with, " I do not deal with the public
any longer, please contact your local dealer". Several years ago
he was great to talk to and very helpful. So maybe I got him on a
bad day.
There is also a Yahoo group for the Pampera. You might try looking
through the past posts. Your carb swap info may be in there
somewhere.
Here is a picture of our Pamperas.


Good luck, Jeff