# Honda 5518 engine doesn't respond to throttle input



## timsch75 (30 d ago)

My Honda 5518's engine doesn't respond to the hand throttle input. I can see the cable moving the throttle plate when I push/pull the control handle.. The engine runs fine, just at a set speed. The other day when I noticed this, I was able to get the RPM down by backing out the limiter screw for the throttle plate.

The tractor did sit for a couple of years before I got it. I've not disassembled the carburator for cleaning or inspection other than to see movement from the cable. What would be the most likely problem?


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## Bob Driver (Nov 1, 2017)

Does it respond if you disconnect the cable and move the throttle plate by hand? If it doesn't, the main mixing jet may be plugged and it's only running on the idle circuit


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## timsch75 (30 d ago)

Bob Driver said:


> Does it respond if you disconnect the cable and move the throttle plate by hand? If it doesn't, the main mixing jet may be plugged and it's only running on the idle circuit


Yes, it does. I found that I have too much slack in the throttle control cable itself. Half of the range of the hand control is taking up the slack. There appears to be no problem with the carb.

Thanks for the response.


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## Bob Driver (Nov 1, 2017)

Yep..... Checking the cable for slack movement was going to be my next suggestion if you got a response from manually moving the throttle plate


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## Bob Driver (Nov 1, 2017)

Your 5518 is a really nice machine, but Honda pulled the rug out from underneath you years ago on parts. Baby the hell out of it where you can. Engine parts on that GX640 are pricey (It's a Honda), but they're readily available. Chassis parts are really tough to find.....


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## timsch75 (30 d ago)

Yeah, too bad about parts availability. I've got that in mind going into it. I've got $0 in it now, and won't be getting stupid with it. I took it on as a challenge to get it running again. 

I pulled off the dash and saw that while there was slop in the connection between throttle hand lever and the plate that connects the hand throttle & the cable, the plate was moving full stop-stop.

There is a square piece (seen best in the 2nd picture) that has been welded to this plate which reduces the range of throttle travel. It looks like an afterthought, but the paint on it looks original. Can anyone verify that the range should be restricted like this? I could grind it off easily enough.

In case I answered the earlier question wrong when asking about the throttle plate, I'll add that I moved the lever on the carburator itself, which did get me what seems to be from idle to full speed.


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