Honda GX270 problem

[Nodroz]

IMO, replace the rusty spring and connector with a solid linkage to the carb. You can use a coat hanger or similar. You can have a spring connection but it isn't really required. Also, tighten everything up, you don't want all that slack!

I also have a return spring on the butterfly lever on the carb. This is an extra safety measure if the linkage was to come off.

The short return spring looks crap. I would get a longer stronger one that goes To another position. JMO.

Thanks for your useful information. I changed the throttle set up, but it's still not as good as I want.

However, I have a more severe problem now. I went for a little drive today, after I've set up valve clearance and other small stuff which I posted before.

Everything was going good, but suddenly, after about 3 minutes while driving, the engine died. I got it back home and I saw fuel was leaking out of the carburetor. I opened up the air filter (the whole attachement to the carburetor) and a whole flood of fuel came out of the carburetor.

Apperently, the whole chamber of the carburetor was filled with fuel. I don't think this is normal...
I quickly took my camera and took a picture:

Is there anybody who knows what could be causing this? Some malfunction or something? Maybe some dirt in the carb (although this is unlikely as I toroughly cleaned it... etc

Regards,
Nodroz

 

[landuse]

You might find that the needle is not seating properly, and this is making all the fuel build up in the carb

 

[Brandon1023]

However, I have a more severe problem now.

Actually, this is not a serious problem at all. It happens commonly, and can be fixed for about $10

You might find that the needle is not seating properly, and this is making all the fuel build up in the carb

Yup. Seems like me and Landuse are the only ones on at this time haha. Anyway, what you want to do is remove the bowl from the carburetor and take the float out of the assembly, too. Pull out the needle, and you should see the seat. It's a rubber plug which the needle plugs in to, making a liquid-tight seal. That plug wears out with fuel, wear and tear, age, etc. Most likely, you need to change it. You can get it in a rebuild kit for about $10. Take a needle nose pliers and pull it out. It's not that hard, but can be tricky if it's your first time doing it. Once you get the old one out, ensure that the new one has the little circular groove face down in the fuel inlet. Once it's flat and the groove is down, gently push it in with a screw or a hex key just small enough to fit in the inlet.

 

[Nodroz]

Actually, this is not a serious problem at all. It happens commonly, and can be fixed for about $10



Yup. Seems like me and Landuse are the only ones on at this time haha. Anyway, what you want to do is remove the bowl from the carburetor and take the float out of the assembly, too. Pull out the needle, and you should see the seat. It's a rubber plug which the needle plugs in to, making a liquid-tight seal. That plug wears out with fuel, wear and tear, age, etc. Most likely, you need to change it. You can get it in a rebuild kit for about $10. Take a needle nose pliers and pull it out. It's not that hard, but can be tricky if it's your first time doing it. Once you get the old one out, ensure that the new one has the little circular groove face down in the fuel inlet. Once it's flat and the groove is down, gently push it in with a screw or a hex key just small enough to fit in the inlet.

I have opened the carb and blow out all particles. The engine appears to be running again without flooding. I didn't need to rebuild the needle, nor the rubber sealing pin.
Thanks for your reply!

 

[MCPDC]

Ok, I will put my 2¢ in regarding leaks. I have not read any of the response above so if I am repeating anything, sorry.
I would not use JB Weld (no offence, it has its place but in my experience not for this). The last leak I had of this nature was with my Honda ATC Big Red, engine casing cracked at a motor mount... anyway... I used JB Weld twice and did not work due to its inflexibility. Instead, someone mentioned this stuff to me :

http://www.permatex.com/brand_right_stuff.htm

I was highly doubtful, but did not want to break down the engine, weld the cases and reassemble so I gave it a shot. Well, I followed directions and applied it. Never lost a drop of oil in 4 years of driving the crap out of that poor, poor machine (that I bought for $200 BTW). It never lost any oil between changes that I could tell and the sealer looked like the day I put it on when I sold the bike for $800. For a quick fix this stuff went the distance. The name of the product lived up to its name indeed.

 

[MCPDC]

...and now I went back when I realized there were two pages to this and it does not look like a crack... sorry to jump the gun... but the product mentioned above works well!

 

[Nodroz]

...and now I went back when I realized there were two pages to this and it does not look like a crack... sorry to jump the gun... but the product mentioned above works well!

Hehe, no problem. We learned something about the product you used. Thanks!

 

[Nodroz]

Alright guys, I'm back here.

As you may know, I had a little problem with the helicoils I installed on this engine. This has been fixed now. I used a normal M10 bolt, with a double nut. I would like to know if it would be possible that the engine shakes the 2nd nut loose because of vibrations?
I can get you a picture if you don't fully understand what I'm trying to say.

Next, once I started the engine without any load and I openeing the throttle 0.1 mm, the engine revved very high and because of the power, the engine almost bored himself in the ground. I think this might be some issue with some mis-allignement in the engine? Or does this seem normal?

I can get you a video if you want too.

I got this engine without the governor attached. I do not know if the governor internals have been removed (they most likely are). To be entirely safe, I would like to replace the conrod. Thanks to r_chez, I got this website: http://www.nr-racing.com/390raceparts.htm

They ship international and the total costs will be around $150, which is do-able for me. I'll just take the GX240/270 ARC ROD that costs $109. Is this good for my engine, because there is a more expensive conrod too...

Next question; how to see if I have stiffer valve springs? Is there maybe some text on the spring?

And lastly, I need a new ignition coil with a spark plug cable; would this do?

 

[r_chez_08]

That ignition coil would do fine, but are you 100% sure your spark plug lead doesn't screw out? read this-
http://www.diygokarts.com/vb/showthread.php?t=14928&highlight=coil+wire

I would get some high grade studs or bolts for the head. Wouldn't trust standard threaded bar (which you previously said you used, forgot to say anything.)

Racing honda gx engines often use high tensile studs. These can be bought in a kit but are pricy for what they are.
I have heard of 'grub screws' like these being used as replacement for the bolts-
http://www.ebay.co.uk/itm/M10-X-60-..._Material_Nails_Fixing_MJ&hash=item43a04aaaa5
Just make sure they are the right length and pitch thread.

The advantage of grub screws is that you can use an allen key to thread them in to the motor. I don't think double nutting should be neccesary, just torque them to the correct torque.

You could also use something like this, but not stainless steel and they should be grade 10.9 or above-
http://www.ebay.co.uk/itm/M10-x-70-..._Metalworking_Supplies_ET&hash=item56449f4b2d

the engine revved very high and because of the power, the engine almost bored himself in the ground. I think this might be some issue with some mis-allignement in the engine? Or does this seem normal?

Don't understand. Vid would be good.
However, please try and stay clear of revving an engine with no load- it can damage it.

 

[Nodroz]

That ignition coil would do fine, but are you 100% sure your spark plug lead doesn't screw out? read this-
http://www.diygokarts.com/vb/showthread.php?t=14928&highlight=coil+wire

I went to the repair shop from Honda and the guy said the cable is soldered on the ignition coil.

I would get some high grade studs or bolts for the head. Wouldn't trust standard threaded bar (which you previously said you used, forgot to say anything.)

Racing honda gx engines often use high tensile studs. These can be bought in a kit but are pricy for what they are.
I have heard of 'grub screws' like these being used as replacement for the bolts-
http://www.ebay.co.uk/itm/M10-X-60-..._Material_Nails_Fixing_MJ&hash=item43a04aaaa5
Just make sure they are the right length and pitch thread.

How will these bolts holt the cilinder head? If I use these, the head will just blow off.
I'll take a picture tomorrow to clarify.

Maybe I should just get a high end bolt and use that.

Does somebody know the answer to the tougher springs?

 

[r_chez_08]

You use a high quality nut on top of the grub screws. A high quality bolt would work too. Dunno why studs are used over bolts in racing Honda gx motors?

Measure the internal and external diameter of the springs, I will tell you if gx200 ones fit. Assuming that there are no springs for sale from nr racing.

 

[OzFab]

Measure the internal and external diameter of the springs, I will tell you if gx200 ones fit. Assuming that there are no springs for sale from nr racing.

Also measure the thickness of the wire, that makes all the difference

 

[r_chez_08]

Yeah, I was going to see if the springs were the same size even of they are not the same strength, then he could use gx200 uprated springs.

 

[OzFab]

If they're slightly longer, good idea

 

[Nodroz]

You use a high quality nut on top of the grub screws. A high quality bolt would work too. Dunno why studs are used over bolts in racing Honda gx motors?

When you bolt the nut, won't the grub screw bolt in the thread even more?
Bascially, with these grub screw, it is the same thing as with a normal M10 screw, except it's much stronger.

Do you guys really think a normal M10 bolt will come loose under the pressure? Can't imagine that to be honest.

I'm going to make a video later today, and a the measurements of the spring. Thanks for your replies so far!

 

[Nodroz]

Here's the vid...
http://www.youtube.com/watch?v=-m-ONnXmP4g&feature=youtu.be

 

[r_chez_08]

When you bolt the nut, won't the grub screw bolt in the thread even more?
Bascially, with these grub screw, it is the same thing as with a normal M10 screw, except it's much stronger.

Do you guys really think a normal M10 bolt will come loose under the pressure? Can't imagine that to be honest.

I'm going to make a video later today, and a the measurements of the spring. Thanks for your replies so far!

Shouldn't bolt in any more, no harm if it does though!
Just use high quality M10 bolts. It will be easier and plenty strong.

Have a look here to see how to correctly install the cylinder head without the bolts loosening. The link is for a gx200 but applies to gx270.

The twisting of the engine is normal. This is called torque which is the turning force. When bolted down the engine will be fine.