Maico 490 Head Modifications

[flyingdg]

That is the way the 440 and bigger maico heads are made ( cut into the stud )

[KTMaico]

Old head and new head



Modified head chamber



Closer look at the head chamber



Repaired Fin, hard to pick after I had to use a Dremel and bead blasted the head.



I still have to do the ceramic coating of the head, piston and the exhaust port after a little port work. Hopefully it will all be done and finished in a couple of weeks (time permitting), and the fun part of run-in and testing can begin. I hope it is worth it all in the end.

Kevin

[Husky500evo]

Any feedback on whether this head mod is worth doing ? I have a couple of projects on the go, that I wouldn't mind having this mod done to, if it makes a noticeable difference.  I am sometimes a bit wary of our USA brothers though, as they can be the masters of hype. Harley Ferguson are the classic example of this, where they can convince people to pay a year 2050 price tag for something that is basically a 1950 product  .

[firko]

I'm having my square barrel 350 head done so I'll let you know when it arrives home Mark. The word in Maico circles is very positive. Brad Van B has it on his Maicos.

[Husky500evo]

Thanks, Firko. I would expect the modification to have a more noticeable effect on a Maico than almost anything else, because the standard Maico combustion chamber design looks very agricultural and primitive (although it seems to work ok). Some of the heads that I want to have done, already have fairly straight forward looking hemispherical combustion chambers, so it may not get the same result to be worth the expense. I don't think that I would get any of my combustion chambers ceramic coated , like KTMaico, because I would logically think that an air cooled cylinder head would be required to radiate the heat out (not hold the heat in). I'm not a rocket scientist, but I think that ceramic coating the top of the piston might be worth trying .

[KTM47]

I agree my 490 needs more power I'm having trouble getting to the 1st corner 1st.  I'm usually 3rd or 4th behind the other 490 Maicos.  Really they don't need to be changed and they aren't necessarily the most powerful, but they do put the power down better than any other 500.

If I get a good jump I'm 1st, the other bike/riders usually get a better jump than me, I can run everyone down except the other Maicos.

The head modification may have more to do with unleaded fuel as I do know it was common to modify 2 stroke heads when unleaded fuel became compulsory.  Please note Classic MX & DT bikes can use leaded fuel. Getting it is the problem.

The real Kevin TM

[2 shocks]

For your consideration Gentleman,

Personally, I dont know why you would want to alter an 81/82 490 Maico, a properly maintained and correctly jetted 490 will hold its own against any Modern 450, ie; with a good rider of course. If you were going down this track, I would definately ring Paul Stacker in Melbourne 039459 9535 and tell him your intentions, Stackers would be the most knowledgable people going around, it might save you time, money and a lot of grief.

Good Luck
Ken Baker #54

[KTM47]

Thanks Ken are you bringing your Maico and your son up to Echo Valley for the Post Classic Champs in April.

Check out the facebook page [url]https://www.facebook.com/events/1382144772030061/?ref=5[/url

Also Harker is # 54

Kevin

[09.0]

I have two with the mod. I promised to do a comparison between standard and modified heads. I'm embarrassed that I haven't yet done it. It shall be done sooner rather than later.

[2 shocks]

Aprils a big month with HBBB and the Aussie Titles back to back, should be right to get there, looking forward to it. 54 is my ex race no from back in the day in Victoria  looking forward to meeting you all.

Ken Baker #54

[Tahitian_Red]

Any feedback on whether this head mod is worth doing ? I have a couple of projects on the go, that I wouldn't mind having this mod done to, if it makes a noticeable difference.  I am sometimes a bit wary of our USA brothers though, as they can be the masters of hype. Harley Ferguson are the classic example of this, where they can convince people to pay a year 2050 price tag for something that is basically a 1950 product  .

HD is not convincing anybody that their bikes are advance alien technology.  People in the Motion Picture Industry, Cable Networks and Print Media have convinced people that the bikes are "cool".

Just like a 1974.5 Maico G.P. is cool, but by today's standards they are junk. 

(I never had any interest in Yamaha DT/RT-1's until Firko and others posted some of their bikes here and I watched "Little Fauss and Big Halsy" for the first time.)

[firko]

HD is not convincing anybody that their bikes are advance alien technology.  People in the Motion Picture Industry, Cable Networks and Print Media have convinced people that the bikes are "cool".

I'm a bit with Jay on this, I don't think Harley Davidson has brainwashed a generation of motorcyclists. I'm sure they're producing bikes for a market that just plain isn't into "crotch rocket" style road race influenced bikes. The fact that they've hardly changed in half a century is the selling point, not unlike modern Triumphs building a visually similar modern Bonneville or Morgan sports cars having changed very little since mid last centuries. These companies have seen a market and concentrated their shtick towards them.

[GMC]

There would be lots of guys in Aust. that can machine squish bands.
The one I know would want the barrel & bottom end including the head and base gaskets so he can calculate the clearance properly

[Lozza]

Rather ironic that with the Aprilia GP program had 100 staff headed up by the worlds greatest two stroke tuner (Jan Thiel) with 2 dynos testing 5 cylinder and head designs for 5 days a week for 13 years settled with a head design like the one on the left above. Jan even thought that head was 10 years ahead of it's time and the design probably came from legend German tuner Jorg Muller.

[Ktm181]

I have two with the mod. I promised to do a comparison between standard and modified heads. I'm embarrassed that I haven't yet done it. It shall be done sooner rather than later.

I like your attitude 090, "can do attitude" is always uplifting, i'd like to know your opinion on the comparison too.  I'd also like to know the chamber volume of both heads as a comparison too, i've ridden a bike with this mod, nice power, long and smooth...BUT it had the compression changed, bore size changed, different carb too..yep the head mod made the difference all right, it was done a fair while ago too, didnt have the "flutes" of the U.s. one but had it welded up an re-machined by a Sydney machinist who is now living the hippy life on the mid-north coast of New South, lucky bastard! He reminded me of this mod late last night over a bourbon, he at one end of the phone and me on the other whilst explaining how his RM250z is running! (no the mod was not on this bike)

n.b. i cant help wondering if, all things being equal other than the combustion chamber shape, if this is not just a detonation fix for a big bore engine?

Kt