ATC 70 - pic - z50 engine

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I have a 1985 atc 70 with a honda z50 engine (off a dirt bike), but is using the stock 70 carb... when i got it it was wired incorrectly, i rewired it and it started on the first pull everytime, however it would always wind out at over half throttle every time (wasn't full throttle cause i could push the throttle and it'd still rev higher), i figured the carb needed cleaned/rebuilt... i took the carb off cleaned it inside and out, got it back together and now i can only get it to backfire every now and then.

My brother was saying that it could've jumped time by reving high when starting it, is there any way to check if the timing chain itself is off a tooth or more without tearing the motor apart? If it has jumped a tooth, is there any way to adjust the points to compensate for the jump?

i've checked points and the gapping is within specs, has a new spark plug, good spark and it's getting gas, any opinions?

i also have the complete original 70 engine for parts, but it's in pieces...

** i already have the 70 and z50 manuals, they are no help with my particular question So if anyone can help, it would be greatly appreciated!

here is a pic of my 70 with the z50 engine (fender/seat and pull start removed)...



Jason

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[night4creeper]

as for the timing, I don't see it jumping unless it stripped a gear; to check your going to have to remove the large round cover on the left side of the head.(its held on by a bolt that goes through the cyl head; the bolt head is on the right side of the cyl. head). then align the cam gear to its mark and the crank to its mark like is shown in your books.

From your initial description, I would have guessed the slide was not in the carb properly and that was causing it to rev up right away. BUT since you have taken it apart and cleaned it and now it will not fire, I'd suggest you take it back apart again and verify everything is clean and the pilot screw is set per the book to start out.

Also you might try holding the throttle open a little--1/4 to 1/2 when starting.

[Gag_Halfront]

Complete shot in the dark:

All you did was take the carb off, do some magic with some chemicals and compressed air, and put it back on? And now it's misfiring? Seems unlikely that the cam chain jumped the last time it was running and you didn't notice. Also seems unlikely that the points would have changed just from pulling the carb. Assuming that you did a good job with the cleaning, what seem more likely are that the slide is in backward, the air or idle screws are fscked, the float is set way way wrong, or the needle is jacked way up.

To me, the occasional pop makes it sound like it's _way_ too rich. Look at the floats and the slide/needle first.

[dcreel]

Make sure that the cable is opening the slide on the carb open all the way