3.5 or 4 HP?

[Motra]

I noticed on this literature that the 3.5 and 4 horsepower minibike engines are both exactly the same dimensions. Same bore & stroke, same displacement, and even the same 2.61 kilowatt power rating, yet they claim different horsepower ratings. Hmmm?

 

[jimh]

Maybe different compression and bigger valves??? That is kind of strange.

 

[Strigoi]

my guess would be the CR or the cam.

 

[Tinker666]

I noticed the air cleaner housing in the PICS. can you still buy those?

 

[blownengine]

You should be able too. They should be extinct yet.
Try ebay.
I got mine from PartsList
Scroll down to E12, "Air Filter Kit"
Some people have had trouble with this site in the past though. His responce time can be a little slow.

 

[minibikedude]

Those look to be the newer power sport engines. I do not know if they the same as the older engine.I ask a similar question to Brandt and he told me that the 3.5 horse has smaller valves and ports and a different cam than the 4 HP engine. He also said the HS40 and HS50 were closer to being the same except for the different exhaust port in the HS50. The flywheels were the same in the HS40-HS50 HP engine and the 3.5 HP engines were different.

 

[Jay Wrix]

thats interesting,

Regardless Whys the kilowatt power the same?

 

[Motra]

All the part numbers are the same and everything. I'm pretty sure they're the same except for the sticker, but who would ever know!

 

[GTO]

I think it's a misprint and they used the same stats by mistake.

 

[ATKRIDER]

The bore is the same. The H35 uses a TINY exhaust valve with the same intake valve as the 4hp. The 4hp has a exhaust valve the same diameter as it's intake valve. The camshafts are the same-same even as a hs40 but they have a compression release built in. I am working on putting the h35 2.500 piston in the old h30 that you cannot get pistons for anymore. The h30 block has the same large valves as an hs40.