GEM Reed Kit

[Kip Kern]

For all of you brave souls who think you have to have a faster 250/400, check out the Gem reed kit offered on ebay under "Penton"

 

[Cathump]

Kip, I have bid on it. What kind of changes can I expect on a MC 5 250?

Rick Terry

[rob w]

Get ready to remortgage the house if you plan on buying that.

Invest a lttle more and have a block and carb spicot cnc machined new, design it around an already existing reed cage and pedals. I'd buy one or two.

 

[imported_n/a]

Bob, Kip, I was thinking of mortgaging the Edsel to pick this up and use it as a model to have them remade.  Of course, I want them to be available to use.  Karl, if that is what you have in mind, be my guest, but I want to reserve two.  

Glenn

 

[tomale]

What can I expect by adding a reed valve to my MC5 250

Thom Green,I own and ride a 76 250 MC5 MX which I bought new.

[Kip Kern]

I have never used one as a stock 250 is fast enough for me.  I have friends who swear by a reed for better power delivery and a few percent increase in HP.

 

[Mike OReilly]

For anyone interested, I have a GEM reed assembly for a 250, and would be quite happy to loan it as a pattern for anyone (Karl?) contemplating having them re-manufactured.
Mike

 

[metalkfab]

Yes,I already 3rd.mortgaged the house.If I get this damm Gem Reed,we will be offering copies-How Soon?? I don't know due to the fact that our other customers are keeping us running from MRP to JIT and back.If I don't land this baby,I will be looking for a unit to copy.

[tomale]

What I am wondering is, would the reed valve smooth out the power. It could be that I need to re jet my bike but it seems to be pipier than I remember. It runs kind of dirty on the low end and then comes on rather strong in the mid range. I am wondering if I need to lean out the pilot jet maybe one size. It is cooler and up here than when I lived in silcone valley and I have not changed anything.

Thom Green,I own and ride a 76 250 MC5 MX which I bought new.

[rob w]

Karl, Investment Casting........Correct?





 

[Mike OReilly]

Thom: Although the 250 Pentons were always a somewhat "pipey" motor, what you describe sounds more like the R.H. crank seal is a bit tired and letting in air;
Karl: If you want a GEM reed cage as a pattern, let me know. No need for the 3rd mortgage.
Mike

 

[john durrill]

thom,
 Just a thought, have you burned out the pipe lately?
 You might just need to clean the carbon and oil build up out. you can use a torch or a wood fire in a barrel. we like the wood fire the best. it does a better job.
John

 

[tomale]

thanks mike and John,
Mike, I just replaced the RH crank seal a month or so ago. It should be ok.
John, I have never cleaned out the pipe. It is not as bad as it sounds. I bought the bike new, right.... well I rode 4-5 times and then a custom pipe was fitted, then I rode it 8-10 times and my life made a significant change..... that was 25 years ago and my bike has only been riden  4-5 times since then. I changed the R seal because I thought it was a good idea since I was planning on riding it regularly. A good cleaning of the pipe is probably in order. I have a fire pit in my back yard that should do the trick. If it was a seal wouldn't it lean the bike out?
the problem may be me, since I have only been on the bike once since I replaced that seal. And it has been a number of years since I rode the bike for more than a few minutes. boy have I missed my bike!
Again I say thanks.... I am finding that I did not really know that much about the bikes I have riden. riding a new bike is pretty easy, just keep up the regular maintance and your pretty much home free, A vintage bike well that is much different, you really need to know your stuff. And I have much to learn.

Thom Green,I own and ride a 76 250 MC5 MX which I bought new.

[JNOYES]

My son and I have a '76 MC5 250 we are prepping to race and are also very interested in the Gem reed kit.  We realize that the price may be astronomical.  Perhaps if we are reassurred that someone will offer a remake of this kit for a reasonable price ($250???)we can keep the bidding down and let everyone win.  Is this likely?  We have also considered the reed kit that Cycle Stop offers for the '73-'74 Elsinore.  It might be possible to adapt this kit to the Penton.
The Elsinore kit is $229 and this seems reasonable to me. I know the bolt patterns are similar.  I think the angle is wrong for the Penton, but perhaps an angled adapter plate would work. Of course, there's the question of how to properly modify the Penton piston.  Anyone out there with the Gem istructions that would be willing to share this info?  Should we fail to win
the GEM auction we will be looking into
the Cycle Stop kit as an alternative.
Although being racers we always are looking for an edge, in the spirit of sportsmanship I will gladly share any information we may
find in this regard with fellow POG members.  

Jon Noyes

 

[[email protected]]

I rode for and worked in a shop in the early 70's that sold Maico's.We got in the GEM kits and I got a freebee so I could promote it's merit to the customer.I was not a good salesman for this product.I did not like the effect it had on the Maico.I put a lot of machine work and time in the project and in my opinion I ruined a good Mahle piston I couldn't afford.But the Maico 250 was a tractor to begin with.So maybe on a more pipey machine it would have merit.Frank