Porting for Maico 490

[KTMaico]

I have been trying to get some information on Porting Spec's on Maico 490's from various people and Maico experts around the world with no success. My cylender has the boost finger ports in the liner, but are bloked by the cylinder walls, my cylinder is a piston port version. I know that on Reed valve versions these ports are open and are used, but if I open these on my piston port cylinder will I be adding or taking away from the bike performance?

Also over the years of the Maico 490's there must have been some documented Port modifications for performance increases, Rick Sieman (Super Hunky) recently had a posting put up on this site by Mark (Firko) about the gains on a Maico 501 after porting and othe engine modifications. I would imagine that there must be some similar info for the 490's. Any and all help would be appreciated.

[090]

Do you intend on lengthening your arms?

[JohnnyO]

I have been trying to get some information on Porting Spec's on Maico 490's from various people and Maico experts around the world with no success. My cylender has the boost finger ports in the liner, but are bloked by the cylinder walls, my cylinder is a piston port version. I know that on Reed valve versions these ports are open and are used, but if I open these on my piston port cylinder will I be adding or taking away from the bike performance?

Also over the years of the Maico 490's there must have been some documented Port modifications for performance increases, Rick Sieman (Super Hunky) recently had a posting put up on this site by Mark (Firko) about the gains on a Maico 501 after porting and othe engine modifications. I would imagine that there must be some similar info for the 490's. Any and all help would be appreciated.

My cylinder is the same as yours.. i'd just leave it and ride it as it is, they go ok.

[paul]

standard 490,s go hard enough stock why stuff around with a good thing

[mxmaniac]

I have been trying to get some information on Porting Spec's on Maico 490's from various people and Maico experts around the world with no success. My cylender has the boost finger ports in the liner, but are bloked by the cylinder walls, my cylinder is a piston port version. I know that on Reed valve versions these ports are open and are used, but if I open these on my piston port cylinder will I be adding or taking away from the bike performance?

Also over the years of the Maico 490's there must have been some documented Port modifications for performance increases, Rick Sieman (Super Hunky) recently had a posting put up on this site by Mark (Firko) about the gains on a Maico 501 after porting and othe engine modifications. I would imagine that there must be some similar info for the 490's. Any and all help would be appreciated.

Are u in Victoria?

[Marc.com]

yeah take 2mm out of the top of the exhaust port and sharpen the transfer ports .... that will do it.

[Lozza]

I have been trying to get some information on Porting Spec's on Maico 490's from various people and Maico experts around the world with no success. My cylender has the boost finger ports in the liner, but are bloked by the cylinder walls, my cylinder is a piston port version. I know that on Reed valve versions these ports are open and are used, but if I open these on my piston port cylinder will I be adding or taking away from the bike performance?

Also over the years of the Maico 490's there must have been some documented Port modifications for performance increases, Rick Sieman (Super Hunky) recently had a posting put up on this site by Mark (Firko) about the gains on a Maico 501 after porting and othe engine modifications. I would imagine that there must be some similar info for the 490's. Any and all help would be appreciated.

They will add some usable mid range

[Davey Crocket]

Jeez Kev....you cant even find your pants....so what are you going to shit in if you make your 490 go faster?

[DR500]

he's got to be able to start it first!!!!

[KTMaico]

No I can't ride a stock Maico 490 to it's full potential, it's about getting a bike I could not afford to when I was racing and doing all the things I could to make it the best I could. 30+ years after I stopped racing, I can now afford a bit more and I have more time on my hands to pursue silly dreams. I will try opening the bike up on a track with no pants on so I can add a little jet propulsion.

[East Coast Maico]

Ever consider a Reed valve cylinder?

[KTMaico]

Ever consider a Reed valve cylinder?

Bill I have been tossing with the idea of a new Reed valve Cylinder for two years now, but I have a problem with justifying the cost against the gain. The new Reed valve cylinders with the Aluminium Sleeves with Nicrosil Coating sounds good though. my maico cylinder is at it's last bore (4-5th over) and is currently 515cc so I eventually may have to as a re-sleeve is a eventuality. Plus i am not a Wiseco Piston fan. I would also probably go with a Mosbarger reed setup. At the moment i am trying to sort out getting a fully Blown RM125 done in the states and then brought here to finish off.

[JohnnyO]

The reed valve cylinder is the biggest improvement i've noticed when riding a 490 with one compared to my piston port engine but is it worth the money?? Reed valve 490's are common in the UK but i don't think many of them were the remanufactured nicasil cylinders.

[KTMaico]

The reed valve cylinder is the biggest improvement i've noticed when riding a 490 with one compared to my piston port engine but is it worth the money?? Reed valve 490's are common in the UK but i don't think many of them were the remanufactured nicasil cylinders.

John they are available now, ask Bill. It is a improvement and a big advantage ove the steel liners. Do you want that top to match your pants (freebie)?

[JohnnyO]

I know they're available Kev but very expensive, i was wondering where the Poms sourced the ones they use?
Thanks mate i could use the top, i'll try and catch up soon.. maybe dirt track titles?