Motorcycles, Snowmobiles, Go-Carts, ATV's and Golf Carts - 1973 Honda 70cc Trike

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View Full Version : 1973 Honda 70cc Trike


quincyj68
08-11-02, 11:26 AM
This trike was just given to me and it won't start. The previous owner said it was running before storage. I removed the spark plug, turned the engine over and there was a spark. I suspect it's a fuel problem. I disassembled the carburetor, cleaned it and reinstalled it - it still doesn't fire. I choked it, etc.

Do you think I need a carb kit? Any other suggestions?

Thanks.


mikejmerritt
08-11-02, 09:25 PM
Hello quincyj68, Ah, the ATC 70, brings back many memories. What I think you should do first given the fact that this 3 wheeler has been in storage is a compression check. This will tell you if this engine has any chance of starting. If you need a compression tester I think Auto Zone has loaner tools and you won't need it long. Pull the plug, screw or hold the tester in the spark plug hole and roll the engine through a couple of times. Check the reading and hope it is around 80 lbs. at a minimum. If you get a low reading spray a good shot of WD-40 into the plug hole and test again. If you pick up 20 or so lbs. that would indicate worn rings, cylinder or both rather than say a bad valve. If you have good compression the next step would be to replace the plug, remove the air filter and give it a shot of starting fluid and attempt to start. You may have to try this a few times but it should hit at some point. Once you know the engine is capable of hitting a few times it will be time to worry about the carb and getting some gas to the engine. Verify that fuel gets to the carb by removing the fuel line at the carb and opening the valve and catching a little gas in a cup. Make sure the fuel you catch isn't orange from rust or have small pieces or rust in it. Replace the line if you have flow and the fuel is clean. Now verify that the float is working properly. You can remove the float bowl and operate the float by hand and letting it down should produce fuel flow and gently holding it up should stop the flow. If all is well to this point reassemble the carb and try starting it the same way you did before with the starting fluid and after a few times it may pick up and run. If not you probably have some sludge restricting the fuel flow in to the engine. This should give some idea where to start on this. I'll check back daily if you would post back your results and any more questions you may have. Best of luck on your little machine......Mike

cheese
08-11-02, 09:27 PM
Hello quincy!

70cc engine? That's small for a trike. Is it a 2-stroke engine? Is the carb bowl filling with fuel? Have you tried dropping a few drops of fuel into the spark plug hole and then starting it?


mikejmerritt
08-12-02, 09:38 PM
Hey cheese, I suppose quincyj68 is still plugging away at that little 3 wheeler. The ATC 70/90 was a staple in our lives in the 70's and for the most part it is a scaled down ATC 185/200 and it is 4 cycle like its bigger counterparts. Check this link for some pics http://www.3wheelerworld.com/yHondaAtc070picturepage1.shtml



Mike

quincyj68
08-13-02, 02:14 PM
Thanks for the URL. That little red one on the right is the one we have. It's a toy (albiet a respected one) for our 9-year-old.

I will pass along the info and I hope we can manage to get it going. Our son is excited at the thought of it working.

I'll keep you posted. Thanks again.

cheese
08-13-02, 09:51 PM
Mike, I guess we were responding at the same time, lol. I guess the term trike threw me. Thats what I call a 3 wheeled motorcycle...made for the road. I've always heard the little off road ones called ATCs or 3wheelers. There aren't many around my area anymore...not since they got outlawed. By the time I started working with small engines, they were all but gone.

Quincy...good luck with it. Let us know how it goes.

Super
04-28-08, 01:34 AM
First thing to do is try a new spark plug as you said you had spark. Ensure that you have cleaned the small wire filter in behind the fuel tap on the carby (remove the 2 screws & the fuel tap lever comes off then access the filter). As others have said ensure your fuel is OK.
Depending on the type of carby fitted, check that the choke is working & in the right position (remove the air filter & look in the carby). You will need it on to start. If you flood the carby, remove the spark plug, clean it & refit (have several new spark plugs on hand).
I have had 70cc Honda trikes for 30 years +. My first one was 2nd hand when I got it in 1977 & now my son & his 5 year old daughter are still using it (it's bored out to 90cc).
My latest projest has been to put a 125cc 4 stroke electric (Thumpster) style motor into the 70cc frame. It is a beast. Had to fit a disk brake to slow it up.
Good luck - Super (Australia)