1981 Honda CM400e - carb problems???

[blynch70]

I hope I putting this in the right place ... sorry if I'm not.

I have a 1981 Honda CM400e that I've owned for 6 years. It has spent most of it's time in my garage but it ALWAYS started right up no matter how long it sat.

Cliff Note Version:
Ugly Divorce / Satan's Sister put dirt in the gas tank and I ran the bike about 5 minutes before I thought to check for sand (after 10 years of marriage you get to know a person).

I pulled the tank and cleaned it out ... she actually grabbed dirt (mostly small pebbles that wouldn't fit through the gas line) and when I drained the oil there wasn't any signs of grit or anything to make me think the dirt actually got into the carb BUT I pulled it and cleaned it just to be safe ... seemed fine.

The bike fired right up, idled a little rough but I figured it just needed to work out some creeks. When I pulled it out of the garage into the darkness I noticed that the left pipe was CHERRY RED. I shut the bike down and let things cool off. The right pipe wasn't hot at all.

I am NOT a mechanic (but I have stayed at a Holiday Inn Express) but I figured the best way to learn is to dive right in ...

I pulled the plugs and put my thumb over the hole when I turned it over. There was enough compression to kick my thumb off on both sides. I know that's not the ideal compression test ... but at least it gave me a start.

Next I pulled the pipes to see what was happening in that neighborhood ... left side HOT right side COLD (no surprise there) and I would get flames out of the LEFT SIDE only when I released the throttle.

I went back to the carbs and cleaned them again (because they are so much fun to get off the bike) and tore them right down. Put everything back together and guess what? Left side HOT right side cold. So to narrow down my uneducated guesses even more I poured a little gas into the right spark hole, replaced the plug and turned her over. BOTH sides sounded GREAT for about 3 seconds ... then of course the gas was gone from the right side and I'm back to left hot right cold.

So I am guessing (again I am no mechanic) it's got to be a fuel issue on the right hand side. I am getting fuel into the right side bowl but I am guessing that's as far as it's going.

NOW, when I was putting the carb back on I noticed that one of the throttle cables was busted (pulled it right out of the sleeve ... rusted away). It's not the one that REVS (or opens the carbs) that cable is working just fine and the throttle does return to "idle position" by itself ... so I'm not sure what that cable actually did/does.

Any thoughts? Tips? How To's? Prayers???

Thanks!

[BananaKatana]

first of all, sorry man that sucks. Sounds like you know your stuff really well, but still I would say please be very careful when it comes to running a motor that has something like dirt in the gas and possibly the oil. It could turn a cleaning problem into a major replacement problem. hell have no fury like a woman's scorn....

[mgdavis]

The broken throttle cable should force the throttle to close, in case a return spring comes loose or breaks.

[blynch70]

Yeah ... a woman scorned ... I'd get into it but it's the wrong forum ... do they have a "Guys who took it up the &$$ in the divorce?" forum??? LOL

Bikes all back together and running, both sides getting fuel and it sounds A LOT BETTER ... however it is running REAL HOT! I have adjusted the fuel intake (the ones that sit just in front of the bowls on the carb) like everyone I have asked said ... I turned them all the way in until they were seated and then backed them out two full turns. Problem is once you get the bowls back on there is only a very limited amount of play in how much you can turn them due to a "stopper" on the bowl. Is the running hot due to too much fuel getting in now? I also need to keep the choke pulled wide open for the little basta... er, I mean the little bugger to stay running ... never had to do that before. I have played with the idle adjustment with NO effect good or bad.

Not sure why it runs so hot ... never ran THIS hot before ... any thoughts?

[Axman]

Almost sounds like a rich condition.

[pvo22]

The bike will run hotter when rich?

[Sev]

No, it'll foul when rich. It runs crazy hot when lean.

Check for vacuum leaks after the carbs, but before the cylinder.

[Axman]

Sorry I meant lean wrote rich! My bad!

[Wrench_Whore]

You have fuel delivery issues.
The engine is running lean.
Check for vacuum leaks.
Check the float level.
Clean ALL the jets including the needle jets.
Make certain all passageways are clear.

[crazypj]

Did you remove EPA plugs on pilot mixture screws to clean those passages?
PJ