[ray_peel]

I have repowered my 420 with a Honda GX630, it currently has less than 50 hrs on it, but from day one, out of the box, this engine appears to be running lean. When engaging the PTO for the 60'mower deck, the engine will cough, or stall. The only way you get mower to engage properly is to be partially apply the choke.
The engine's High Speed, or wide open thottle, seems to be too low also. I have double check the throttle linkage, and appears to be adjusted correctly. Is there govenor speed adjustment without changing springs?
Any suggestion would be greatly appreciated.

 

[flymo]

Ray, is there no mixture adjustment? Or maybe you need a different jet?

I wouldn't be surprised if it's delivered lean from the factory - most newer motors seems to be leaned way out, presumably to reduce emissions.

Tim

 

[knottyrope]

California engines are leaned out and there are jet kits on ebay usually to make them richer

 

[tomd999]

Hiya,

What do the plugs look like? Really light tan or white? May want to pop the tamper plugs off the idle mixture screws and richen up the idle circuit, might help a little.

May also be your gasoline/ethanol mix, the more methanol in the fuel, the less power you make and the leaner the mix. May want to see if you can find straight up gasoline and see if that straightens it out.

Other possibilities:
1) leak in the intake
2) Plugged or restricted main circuit in the carb possibly from ethanol corrosion

Tom

 

[ray_peel]

I can't believe that I am the only one that has had this issue, with this repower project.
I am going to try drilling out main jets .004" and see if doesn't help.
I believe you need special tool to adjust Idle mixture screws. where could I purchase this tool.

 

[ab318]

Raymond,
I had to increase the max RPM of my new GX670, it was too low.
I can't remember how I did it but it was very simple without the need of special tools.

I had another problem with premium gas because the engine was too cold and the plugs became extremely dirty.
I agree with Tom, the color of the plugs is a very good indicator to help for a diagnostic.

Good luck and keep posting.
Andre

 

[flymo]

Ray, with a little poking around, you can usually find the adjusting tools on Amazon - at least that worked for my Husqvarna trimmer, which came so leaned-out it wouldn't even run.

Tim

 

[dalekast]

Ray: Before drilling ports in the carb, you may want to check the valve clearance, and ensure both sides are set to specs. I had a backfiring issue, and narrowed the intake valves, in an attempt to alleviate it. It did rob the engine of some power, but I have no problem w/ a 46" deck and PowerFlow, and the engine turns 3500 RPMs. Have you tried disconnecting the throttle linkage, and moving the governor by hand? If you are able to get the RPMs in doing this, then something is not right w/ the throttle linkage. Are the belts on the mower deck moving freely and traveling the correct path? Seems like there are a few options which w/b less painful than boring out the carb.

 

[ray_peel]

Thanks Dale for the reply, but this is a brand new engine, would hope the valve lash would be correct at this time. Like I mention this conditon was right of the box. Have not experiance back firing conditon though carb.
As far as high speed RPM, I had already have disconecting of the thottle cable, to eliminate the cable issue, thats fine. Studied it alittle this weekend, I believe I have to relocate the govenor spring to another hole closer to the falcum or govenor shaft, of the govenor arm, to raise the rpm. It is currently position in the 3rd hole of 4 away from the falcum. To relocate spring, the muffler needs to removed, right now don't have time to do that. It may be winter project.

 

[mikeduwe]

Have you modified the air cleaner system? What exhaust does it have? That stuff affects the carb calibration.

 

[ray_peel]

Mike, the air cleaner is stock, and the exhaust system is what came with repower package from the COMPANY.
Thanks
Ray

 

[woodpecker41]

Raymond have you asked THE COMPANY about your problems. They may have had other kit buyers with similar problems. Roger

 

[ab318]

Raymond,
You said...
"When engaging the PTO for the 60'mower deck, the engine will cough, or stall"
Did you try to engage the PTO at idle speed?
With my GX670 I can't engage the PTO at idle speed and everything is original including the muffler.
If I remember, it was possible with the Onan.
Andre

 

[knottyrope]

my 420 and 430 wont engage PTO at idle

I put it at about 1/4 on 430 and about 1/3 on 420

I cant get the 420 to idle with PTO on and the 430 chugs a bit but will do it

 

[vmf214]

Ray,
I have the GX630 in my 420 and it is running strong. I'll try to get a picture of my carb linkage over the next few days. My kit was from THE Company as well. I engage my deck at about half throttle without issue.

 

[rustyknuckles]

For what it's worth, on my 425 I have to partially choke the engine while engaging the PTO for the mower. This is when the engine is cold or partially warmed up. When it is fully warmed up, it is not necessary to do this.

 

[ray_peel]

Thanks everone on your responses, I always have thottle at half, or at high, and still coughs or stalls without appling some choke.
Now got another problem, its electrical, a erratic condition, can be mowing for about 5-10 minutes and the mower or front pto quites, sometimes engine quites too. Usually the mower will drop out, and then engine will follow. Sometimes it fires right up, and sometimes I have let sit for 10-15 minutes before it will start. When this happens no starter motor. I did normal checks clean battery connections check and clean wire connections, changed out PTO switch, no help. Then noticed that blue wires coming out of iqnition switch were getting warm, so replaced iqnition switch. Warm wire conditon went away, but now when engagine pto the battery light comes on. Check battery voltage engine running with pto off, 14.6 volts. With pto engage got 12.3 volts. Went out tried to mow with this condition, ran about 20 minutes same thing happen, mower quite, follow by engine dieing. When retarted now the Pto would not engage, no lites. Does this sound like a faulty Timing Control module condition?

 

[woodpecker41]

Charging system on the engine is not large enough for the load on it. The reason could be a bunch of things including bad voltage regulator, bad stator, bad wiring, at one time the battery was jumped or connected with the positive and negative posts reversed. Could be the PTO is going bad and drawing to many amps when running and warmed up. It would be easier to trace with the tractor in my garage. A new car with the engine running and all the accessories on is expected to have a voltage in the high 13 volts to lower 14 volts range. At 12.3 volts the battery is draining. Could even be a bad battery that won't charge. Good luck with this one. I doubt it is a timing control module unless the module has a direct short in it. Roger

 

[ab318]

Question for the expert:
The Charge coil options for the GX630 are 2.7A, 17A or 26A.
Is it possible to have this charging problem if this engine is equipped with the 17A and the working RPM is lower than the normal 3600?
Andre

 

[ab318]

Raymond,
The original wiring of the 420 and the wiring suggested by Honda for the GX630 don't use any blue wire at the ignition switch.
Can you show the wiring used with your kit?
Andre