Cold Blooded Honda

[frugalangler]

Frequently off idle stall is caused by varnished fuel in the jets, there's a different jet for idle vs. power on most carbs, and if it's not been run for a while and was left w/ fuel that could be cause.

 

[eddie48]

frugalangler has it right. If it is running well with the choke partly on, then it is likely that it is starving for fuel. Likely cause of that is as frugalangler said. I've never used Seafoam, myself, so I can't speak to its worth. If I had the problem you describe, I would remove and clean the carburetor paying particular attention to running a very small wire through all of the fuel orifices and using lots of carb cleaner.

 

[Ford850]

Agree with the 2 above... likely a carb issue which might be corrected with cleaning. I do like Seafoam, and have corrected a few rough running engines with it. One was very difficult and I hot soaked plus treated the fuel. Then I had to heavily treat the fuel and ran it that way for several tanks, and it cleared up nicely. Although that was an older B&S Vanguard engine. I have a smaller Honda that surges and SF helped it some, but never has fully corrected the issue. After researching, I found a lot of complaints about Honda engines surging with no good fix even after carb replacements.

 

[NibbanaFarm]

Makes sense, a partially clogged jet. I have always treated the fuel with Star Tron from day one. And it hasn't sat all that long. But could be just a speck of dirt. Unfortunately there's a whole bunch of new snow to deal with first. Thanks for the help everybody.

 

[Sawyer Rob]

It's a HONDA!!!

Honda air cooled engines hate cold weather! A huge pile of money has been spend to "fix" that and all kinds of fancy things have been devised...

Some company's have dumped using Hondas in their products just for this reason.... Like Norwood, they quit putting big Honda motors on their sawmills because of all the complaints about poor running in the cold... A producer of tree trimmers not far from here quit using Hondas on their trimmers, ALL because of cold weather running problems.

Even Honda has designed a shield for some of their motors, to direct some engine heat toward the carb, to make the engine run better in the cold.

SR

 

[Ford850]

NibbanaFarm, Do you still have the aluminum shield on the BCS? I just remembered you built that to protect the engine from snow, and I would think it would hold in some heat too. But what Sawyer Rob says might be the issue if this is the coldest weather you've used the blower.

 

[Kyle_in_Tex]

I just did the annual maintenance so filters and fluids are new or cleaned. Fuel strainer in the carb was clean. Manual choke. When the choke is partially closed it runs good. The only thing I didn't do was change the spark plug. I treat all the fuel that goes in it and it only sat for less than a month. Very hard pulling that engine over. Will try some 0w-30 and a new spark plug.

Not the main jet, but the pilot jet or idle circuit jet in your carburetor is clogged. I have an old wire brush that I pluck a needle/wire from to stick into the very tiny holes that are usually located where the butterfly valve almost closes shut creating a venturi in the main bore. I only use carb cleaner in a can to try and clean the carb's bowl and major gunk out. It usually won't clean out the idle orifices without the wire.

If what Sawyer Rob says is true about cold natured Hondas, then you need to drill out the pilot jet with a very small next available sized drill. This will probably be somewhere in the neighborhood of .010-.015, but measure to be sure. This will enrich the mixture to make it idle better.

 

[frugalangler]

I had a snow blower years ago that actually had a shield over the exhaust that directed warm air into the intake - I've had numerous of the same type engines on summer equipment, but none of them had that shield. That snow blower would run (and idle) in the coldest of weather, it was absolutely amazing how well it stated and ran. I sold it to replace w/ a new bigger machine, wish I'd kept it, it blew circles around the new one!

 

[NibbanaFarm]

It's about 9 degrees F and it just took me about 20 minutes of hard work to get the thing running. I don't have my snow shield on because I'm using it to plow, not with the blower, so there isn't that much blowing snow to get things wet. It might help if I put it on. That's another problem with this engine for cold weather. If there is blowing snow, the snow melts on the engine and freezes the governor.

If Sawer Rob has a link to any of these Honda fixes I'd appreciate. I really hesitate to drill out any jets because I use this tractor in the summer a lot and I don't want any problems in hot weather.

 

[Ford850]

Here's a link to a nice Honda Carburetor troubleshooting guide. The GX390 is covered on pages 3-50 through 3-59.
http://www.ipspower.com/images/docu...buretor-Troubleshooting-Manual-Compressed.pdf