Johnson hd25 success + what material to make gasket from?

[nabiul]

Well it took probably over 50 hours worth of work, but I have my seized, rusted through, corroded heap of junk working, although with medium to low compression. A little cleaning of the points and re soldering the wires to the coils and now it reliably starts. Thanks for all the help guys.

During the rebuilding process I tore up the carburetor/exhaust gasket and replaced it with one made from glossy card paper. Given that the original was some kind of rubber and not metal, could I just cut one from vinyl or use RTV?

 

[gm280]

Post some pictures of what you are working on and we can offer suggestions.

 

[nabiul]

http://imgur.com/joA822x

http://imgur.com/cxDHMH4

http://imgur.com/FAk5OfY

As you can see, the exhaust and intake are connected to the carb and use a single gasket. I have noticed the carb is kind of finicky, one of the screws for cleaning the carbs passages loosened up a bit from the vibration and it was like the motor became scrap metal instantly, would not fire at all.

 

[gm280]

http://imgur.com/joA822x

http://imgur.com/cxDHMH4

http://imgur.com/FAk5OfY

As you can see, the exhaust and intake are connected to the carb and use a single gasket. I have noticed the carb is kind of finicky, one of the screws for cleaning the carbs passages loosened up a bit from the vibration and it was like the motor became scrap metal instantly, would not fire at all.

Interesting old engine. I would go to the auto parts store (most anyone) and buy some gasket material and trace the old gasket and cut out a new one and install. That gasket is really not the difficult to remake... Let us know how it all works out... :thumb:

 

[burnt clutch]

I have the same engine and made the same gasket last month. I used Felpro part # 3157 gasket material and so far it is holding up, bit I only have about an of running time hour on the engine. Here is a neat tip on making gaskets using the mating part as a template. I'm going to try this next time.

http://www.hemmings.com/hsx/stories/2010/04/01/hmn_tips1.html

Good luck.

-Karl

 

[nabiul]

I've gone to all the local stores and the only material they carry is felpro karropak and cork, the cork is too thick and karropak looks like it's just recycled carboard.

I'm in a bind now because while the engine ran beautifully for that one day, when I took it out on the water it fired up once and then died completely. Got it back home, tore it apart and everything looked normal except for an oil film covering every single gasket including the head gasket.

 

[nabiul]

What does it mean if my engine has an easier time starting and running with the throttle valve removed completely and the intake left exposed? Also the engine's RPM is not stable despite no movement in the timing plate.