Hello all,
Thought I'd try to get some help on a Honda Tiller I'm working on with a GX-240 engine. The engine starts on first pull but surges badly at idle. Runs smooth at full throttle. I've noticed that if I slide the choke 3/4's, the engine will idle smoothly. So, I'm assuming the engine is running lean. I've removed the carb and cleaned it thoroughly...I've also drained the fuel tank and poured in fresh fuel. The carb did not appear very dirty at all inside. I also cleaned the spark plug and regapped it at .028-.030. Also tried another plug...no difference. Any suggestions out there? When searching for similar problems on the forum, one person said that they discovered the manifold gasket was put on upside down causing the carb to suck air. This isn't my Tiller so I'm not sure what the owner has taken off/replaced. Anyone happen to have a viewable diagram of the manifold gasket placement available so I can check this engine? Thank you.

You can look up part diagrams here:

http://www.superxpower.com/pages/custompages/viewcustompage/952/Honda_Parts_.aspx

Most often then not, it's the pilot jet in the carburetor that's restricted and causing this surging.

I took the carb off again and it appears that the gaskets that are on each side of the carb insulator (I can only get at the outside one at the moment) seem very hard and possibly not sealing very well. They almost seem burned but there is no burn marks. Seems the gaskets/insulator are stuck to the engine...I assume I'll have to pry them off? Does this sound like a good place to start ordering parts? Thanks.

any time you do carb work you should replace the gaskets. I would lean in the direction as pointed out in the other post. you have a clogged pilot valve, or one or all three of the transition holes are clogged .

Sounds like good info to me! I always seem to buy just what I think I need and then find out that I should have purchased a complete gasket/rebuild kit! Thanks for steering me in the right direction! I'll keep this thread going when I discover the cause of the surging.

While a leaking mounting gasket can cause an issue, if they are stuck on they are probably sealing good. An easy way to test for an air leak at the mounting gaskets, is to spray carburetor cleaner or brake parts cleaner around the area while the engine is running. If you notice any change in the running when you do this, then there is a good indication of a leak.

While it's always advisable to replace the gaskets once you break the seal, I rarely replace the mounting gaskets, unless I tear them.

I tried the carb cleaner around the gaskets, no change in the way it was running. Also, the idle or low speed needle (only adjustment on the carb) doesn't respond at all no matter if I close it completely or open it up several turns. What's funny is, I was able to spray carb cleaner out of all the orfices, especially the idle adjustment orfice...everything looked very clean and even the needle looked good. I can clean it again but it seems as though I'm beating a dead horse!?

Fluid can pass straight through the side of the pilot jet, it's the small orifice that leads to the fuel inlet that gets clogged. A replacement carburetor is not expensive for most Honda engines and may actually be cheaper in the long run then replacing parts in the carburetor which can be more expensive.

A replacement carburetor is not expensive for most Honda engines and ma actually be cheaper in the long run then replacing parts in the carburetor which can be more expensive.
I agree, i know that most of the honda gcv engines the carbs retail around 15 to 25 bucks , the gx carbs a more but may be worth replacing to get past the aggravation.

Well darn! I've already ordered some parts, intake gaskets and carb kit. I did look at what a new carb would cost...for a GX240, I think the cheapest I found was about $56 or $66...anyone able to find one cheaper?

need the serial number off your engine or the part number for the carburetor, to see if any of my sources are cheaper.

Well darn! I've already ordered some parts, intake gaskets and carb kit. I did look at what a new carb would cost...for a GX240, I think the cheapest I found was about $56 or $66...anyone able to find one cheaper?

There is a HUGE price difference in the price of a " T " spec carb for a GX engine,vs the non-" T " spec.(" T " stands for made-in-Thailand.)
So when looking up the number on a carb for a gx160 for example,the carb for something like a Gx160TU,costs around $27.00,and the same carb for a GX160 goes for like around $70.00 or so.Might be worth checking out.I've been able to save our customers lots of $ that way.This tip came from our Honda service seminar instructor,by the way.

Steve

Ok, I installed the new carb kit, new gaskets...changed just about everything that could be changed. Still surges like a son of a pig! So, if you guys could help me locate a replacement carb for a reasonable price, I'd be most interested! I have had no luck locating one because some of the numbers that I've found online don't match anything that I have on the engine! Anyway, the GX-240 is on a Tiller. On the front of the motor, it has the serial number stamped in the aluminum block...on top it has FY1*(asterisk), below it has GC04-3126255. Please guys...I'm running out of hair to pull out!
p.s. I did get the carb number but again...can't seem to find any real matches online! BE15KAB. Now, the "A" appears to have a little stamped box around it so...it might be a BE15KB!? Why does Honda make this so difficult? Because they can?

i will run the serial # tomorrow at work and get you a price from us we are a honda dealer.

Ok just found it, its a be15kb the part # is 16100-ze2-a02, I can get it for you for 57.00 + shipping .

rotti1968, Thanks for the response! You know, I forgot to tell you that the carb kit that I got seemed to have all the parts except...the pilot screw (most likely the culprit) did not fit! The tread pattern was different than the original (clearly a courser thread) pilot screw...so, I had to use the old one. By the way, perhaps you could PM me and give the the info so I could order a new carb? Price sounds reasonable.

Rotti1968, I was hoping you'd give me the website or phone number so I could order the carb...just impatient is all. LOL Anyway Rotti or 30yearTech, do you guys think that if I have the new pilot screw (that I didn't get), it would solve my surging problem? From what I've read in this tread, it seems that most everyone thinks that the pilot valve is plugged but it's clean as I can tell...

if you breakdown the carb for cleaning,remove the idle adjustment screw all the way out (black screw) under that screw is a small black rectangular piece,carefully pop that out with a screw driver, this is an area that gets neglected during cleaning that a lot of the time will cause the surge.blow light compressed air through all openings on the carb then put back together and try it.

Thanks rotti...I'll try that in the morning...could you PM me the info so, if this doesn't work, I can order that carb you suggested in the morning? Thanks.

Opps! You already PMed me...thanks!
Keith

Do as rotti suggested, that black plastic plug under the idle stop screw "IS" the pilot jet on this carburetor. There is a tiny orifice on the bottom and it needs to be clear. I would bet this will take care of your issue.

:thumbsup::thumbsup:

Well...might I say...you guys have it together!! I did exactly what you said and walla!! No more surging! I owe you guys! Thank you, thank you!!!:wave::thumbsup::thumbsup:

p.s. rotti1968, nice talking to you on the phone! Also, I removed the plastic pilot valve...there were two of those small o-rings on it, top and bottom. So, I figure in the kit, they gave you two spares!?