Engine Accelerating

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randymir
United States of America
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Joined: Wed Sep 16, 2020 8:05 am

Engine Accelerating

Post by randymir » Sat Oct 24, 2020 6:30 pm

I just recently purchased a 710K. When driving it home it was sputtering and backfiring anytime I went up a hill. I upgraded to SSI and replaced the plugs, hoping this would resolve the problem. The plugs had black soot, so I am assuming this is a carburetor issue. Since I'm not familiar with working on carburetors I decided to wait and see if the problem came back. Today, it came back and was much worse than before. I could barely make it up a slight incline unless I was in second gear. Anything else and it was lose it.

The real concern was the engine started to race out of control. It was as if I was giving it full throttle. My wife about jumped out of the Pinz. I pulled over and cut the engine. Every time I started it, the engine would race. I discovered if I gave the gas pedal some back-pressure it would ease up. At times, it was fine and then kick in again. Granted I haven't looked at anything yet, but thought I would throw this out there to see if anyone else has had a similar experience. It could be a couple of problems such as carburetor, linkage, etc.

I know the first thing to do is work on the carburetor, timing etc. For the timing, I assume I need a 24 volt timing light, yes? I have a 12 volt, so could I just connect it to a 12 volt supply and use that? I'm mechanically inclined, but should I take this to someone familiar with working on carburetors or do you think I could do it myself, with the right tools and help from this forum.
'74 - 710K
Randy
WB6OSK

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pcolette
United States of America
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Joined: Sun Dec 10, 2006 7:38 pm
Location: Southwest Wisconsin

Re: Engine Accelerating

Post by pcolette » Sat Oct 24, 2020 7:02 pm

Use your 12 volt timing light with a seperate car battery. I've done this for years and it works fine. However, if you have PinzSSI there is no need for a timing light. Simply follow the directions that came with the SSI kit.

Your engine racing problem may be as simple as a broken or disconnected spring on the throttle linkage. Or the linkage(s) may need adjusting. I would start by just giving the engine a good hard look over with the appropriate diagrams in hand. While strange and challenging at first look, the engine is really pretty straightforward.

I've never been great at rebuilding carbs and the Pinz carbs are relatively sophisticated in my opinion. I would consider sending them to Jim LaGuardia at Goatwerks in California.

Good luck!
Paul C.
_________
'73 Swiss 710M
'89 Puch 230GE
2002 MB G500

ChickenPinz
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Re: Engine Accelerating

Post by ChickenPinz » Sat Oct 24, 2020 7:27 pm

I second that. If they've never been rebuilt, just pull those carbs and send 'em off to Jim L. for some TLC. He does them all the time, and will run them on a test engine to ensure they're working well before shipping them back to you.

Mine was very balky and prone to backfires when not throttle-pampered before carb rebuild, but afterward all those nasty personality quirks went away and it was much smoother. Better starting, and better running. It's still a cold-blooded machine that needs a few minutes to warm up before you ask for horsepower, but once warm it's much better than before carb work.

As to racing, as mentioned by another, just check the linkage to see that it's all smooth. Things are a bit exposed under the gas pedal, so there could be rocks/spiders/sticks/gunk getting in the way there.
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pcolette
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Joined: Sun Dec 10, 2006 7:38 pm
Location: Southwest Wisconsin

Re: Engine Accelerating

Post by pcolette » Sat Oct 24, 2020 7:50 pm

Here's a photo showing the spring that keeps the linkage tight and the accelerator pedal up. The bracket can be rotated after loosening the bolt to adjust the spring tension.
IMG_3474.jpeg
IMG_3474.jpeg (399.38 KiB) Viewed 679 times
Paul C.
_________
'73 Swiss 710M
'89 Puch 230GE
2002 MB G500

randymir
United States of America
Posts: 13
Joined: Wed Sep 16, 2020 8:05 am

Re: Engine Accelerating

Post by randymir » Sat Oct 24, 2020 8:36 pm

Thanks for the replies. I will look into Goatwerks. The nice thing is they are only a little over an hour from me. That's not Pinz time. :-)

Pcolette - Thanks for the pic.
'74 - 710K
Randy
WB6OSK

randymir
United States of America
Posts: 13
Joined: Wed Sep 16, 2020 8:05 am

Re: Engine Accelerating

Post by randymir » Sun Oct 25, 2020 2:13 pm

I found the problem with acceleration. The back carburetor's linkage fell off. Reattached, but still getting the sputtering. I had thought it had the SSI kit, but was mistaken. It has a new coil, wires and spark plugs. Looks like I need to purchase the SSI and get that installed, so timing could be an issue.

Waiting to hear from Goatwerks and will work with them to rebuild the carbs.
'74 - 710K
Randy
WB6OSK

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