78 MC5 250 stuck forks

[454MRW]

I remember reading about this in a previous post before the site crashed, but couldn't locate it now. The forks on the 78 250 I picked up a month or so ago has the front forks stuck to the extent that when tying it down to bring it home, I could just barely compress the front end even after letting the air out of the schrader valves on the top of the forks. I thought at the time that due to the cold weather, possibly condensation had built up and frozen in the lower fork tubes, but even when it warmed up, they won't budge. I have another pair of 38mm Marzocchi forks and the correct triple clamps I bought that I will put on the frame once it is painted after putting new seals in them, but I was wondering if there is a check ball or valve that is stuck, or how to go about freeing them up for later use. Thanks for any assistance you might be able to give me.

Michael R. Winter
1974 250 Harescrambler
1977 250 MC5 Project
1978 250 MX6  
1979 250 KTM Project
1980 250 MX KTM

[sachsmx]

I too have had this problem with marzocchi forks and found that it was due to dirt built up below the seals sitting for many years. I have used a propane torch to heat the lower tubes (sliders) just below the seals where the bushings are and it will usually expand them enough to break loose. Most of the time there is no damage to either the slider or the tube from the dirt and the heat from the torch will not cause any harm either. All that is needed is a thurough cleaning and new seals. Good luck.

[454MRW]

Thanks! Do you know if Al has 38mm Marzocchi seals, or where the best place to find them is? If I recall correctly, he only lists up to 35mm in his catalog. Looks like I'm going to need a couple of sets.

Michael R. Winter
1974 250 Harescrambler
1977 250 MC5 Project
1978 250 MX6  
1979 250 KTM Project
1980 250 MX KTM

[pketchum]

Mike,

Yes, I've purchased a couple of sets of 38mm fork seals from Al Buehener.  Tell him I said hi.


Phil

[tomale]

I have bought 38 mm seals from Al and they are fine but if you need them faster than that, I have picked them up at almost any bearing shop. They have books to cross reference them and can more than likely give you several choices. The dust boots are another story. but Al should have them. Good idea the use of Heat but be carefull because there are Nylon bushing in there, and it would be a good idea to move the dust boot out of the way. drain the oil too. good luck!

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
75' GS400 (project bike)
72'sixday (project bike)

[wolfmanonapenton]

Off bike take caps off,take springs out,go buy a gallon of liquid wrench at tractor supply,fill half full of liquid wrench,kerosine,diesel fuel,atf,or a combination!let sit a few days or weeks,find a set of aircap tops or find a pair of airvalves and assemle in your caps for for valves? now install leaving your mixurein the fork leggs,now put about 10pds of air in each legg,let sit for a day or longer?do not put more than 40pds in them as seals will blow up and make a mess so best to leave setting out side so incase they pop they won't mess in your shop!if that dont get it I don't know what will!!!![}:)];)never run more than 7pds if your riding bike!