78 Honda Express Oil in Exhaust

Hello all,

I am new here and everyone appears to be friendly and knowledgeable so its a pleasure joining the community. I purchased a Honda 78 Express a few weeks ago. I am having trouble getting the old girl to run consistently.

I can get it to run for about 5 seconds with a little help from starting fluid. After the 5 seconds I get quite a bit of oil coming out of the exhaust pipe. It has good spark, and im getting fuel to the carburetor. I'm wondering if any one else has had similar problems and solutions. I have a feeling the piston rings are shot. Where would be a good place to begin what seems to be the beginning of a wild goose chase.


Captain Mopedo

Re: 78 Honda Express Oil in Exhaust

Sounds like your gas to air ratio might be off, do you have the gas on the side to control your gas line like reverse gas or gas full on?

Re: 78 Honda Express Oil in Exhaust

Sounds to me like the Express has sat for quite a while and the oil pump is a bit leaky, as they usually are.

Honestly, not a horrible thing, as it will keep everything internally lubed up, but a problem when it comes to running it. Anyway...

Pull the exhaust off dump out any oil and burn the rest out over a fire, lots of tips on here on how to do that. If your feeling really bored and have lots of time on your hands, pull the engine and drain the crankcase of any oil that has leaked past the oil pump and collected there. clean the oil pump and put her all back togerther and fire it up.

Re: 78 Honda Express Oil in Exhaust

Thanks for the advice. I have a feeling it was the oil pump. It runs like a champ now though. I am still getting oil sputtering out of the exhaust though. Is this normal or is there something else i sbould be looking in to fixing?

Re: 78 Honda Express Oil in Exhaust

briny briny /

Too much oil spitting isn't normal. There's likely a bunch of unburned two stroke oil in the exhaust pipe.

Take the pipe off and first pour what oil you can out of the pipe. Make it easier on yourself by heating the pipe with a propane torch to make the oil more viscous. Then pour in some full strength Simple Green and shake and slosh it all around for a few minutes. Leave in the pipe for about fifteen to thirty minutes, shaking and sloshing occaisionally. Full strength Simple Green works great as a degreaser. It's fairly cheap and most importantly, it's non flammable and non toxic. Pour out the oily mess before doing the next step.

For the next step, you may as well decarbonize the pipe by scraping off all the carbon you can in the header and the stinger. Use any tools that work. This will also get rid of unburned oil sludge as well. You can use a drill with an appropriate bit or even a Dremel if you're careful. With the drill motor, you can make a tool (for free) that gets further into the pipe by cutting the straight portion out of a wire clothes hanger, bending one end a bit, and using it like a roto-rooter. Careful with the power tools and only use them at slower speeds.

Then, put fresh full strength Simple Green back into the pipe, shake and slosh it around again, and then let it soak for another few minutes. Make sure to get the solution all through the pipe. Then shake and slosh it around more and finally pour out the mess. After you pour out the oily slop, use a garden hose with some high pressure and squirt what you can through the pipe. This will get rid of most of the unburned oil and sludge.

After the shake, it's time for the bake. Heat the pipe again with the torch and pour out what remaining oil/Simple Green you can. Then, keep heating the pipe by directing the flame all over the pipe and burn out anything left in the pipe. It's going to smoke alot and it's going to get really hot, so be safe when doing this. Don't overdo the heating at the silencer portion of the pipe. In general, you're just looking to make all remaining liquids and deposits go up in smoke and steam.

After the bake step, let the pipe cool. Your exhaust pipe should now be free of unburned oil and sludge and free of carbon deposits. You might want to paint it at this time, and it's a good idea to replace the exhaust gasket at the cylinder. Bolt it back up and you're good to go.

Job done.

Re: 78 Honda Express Oil in Exhaust

Hey Andy, congratulations on your new bike. If you look around online, you will find a YouTube video by Josh Cranston on how to remove and clean your oil pump. That will also give you a chance to check it for obvious mechanical problems. If you continue having serious problems with your bike running, and you conclude that your oil pump is leaky, you can always remove it, block the hole, and switch to premixed fuel. Good luck to you!

Re: 78 Honda Express Oil in Exhaust

i'm with the oil pump idea, youll probably also need to burnout or replace your exhaust

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account