Planet Minis

HaiSpeedZ50R · 07-10-2009, 07:14 PM

Hey guys I just got a '85 ATC70 bottom end that I'm about to take apart for the transmission and was wondering if I can use the oil pump to upgrade my z50 stock unit? Does it have more oil flow? Just trying to figure out what other parts I can take from it so I can get all of my money's worth.

kawik01 · 07-10-2009, 07:24 PM

i'd imagine that it would give more flow beacuase bigger motor=more oil needed but you may have to mod the mounts or something

HaiSpeedZ50R · 07-10-2009, 07:50 PM

Yeah that's what I figured too but I think I read somewhere about the "drive" apart of it being different. Hmm I wonder if the cases or crank are good for anything?

kawik01 · 07-10-2009, 07:51 PM

i wouldnt know

mexicanyella · 07-11-2009, 12:35 AM

"Hmm I wonder if the cases or crank are good for anything?"

Sure, they're perfectly good for spares. The cases are not ATC-specific other than the serial# stamped in. The clutch cover will have the kickstart hole blanked off, but you can find other clutch covers to fix that issue if you want to build a kickstart motor around one. The flywheel cover will have the pullstart assembly, and a little hole for the gear position indicator spindle, and I'm not sure if the flywheel is the same as a 6V points 2-wheeler flywheel or not once you remove the pullstart cage. The little gear indicator pointer screws into the shift drum and on a bike would normally be a plain bolt covered by a rubber plug. With a bike-specific flywheel cover (and maybe flywheel; not sure if ATC flywheel requires deeper cover or not) and a different clutch cover and the bolt/rubber plug in the shift drum instead of the pointer, you've got a bike engine.

Well, in your case I guess you'd need to add a top end and some transmission innards too.

I think all ATC70s used the 6V points ignition, and will have a particular taper on the flywheel end of the crank which is different from later CDI motors. But I thiiiiiiiiink that taper will be the same as a 6V points-ignition bike, so it could be a spare for an automatic-clutch 6V points engine.

*I'm basing this off of examining a '77ish ATC motor I have here. Most of one, anyway. There may be changes to the 80s ones I'm unaware of. Chime in, anyone?

HaiSpeedZ50R · 07-11-2009, 01:04 AM

Spares would be nice. . . if I had another atc..hehe. I'm using this bottom end as a donor for my Z50R's 3 to 4 speed conversion. You're right about the gear indicator thingie..other then that I guess it's identical to a 6v 50 motor.

07-10-2009, 07:14 PM	#1 (permalink)
HaiSpeedZ50R PM Newbie Join Date: Jun 2009 Location: Palm Beach Posts: 92 My Mood:	Difference in ATC70 and Z50 Oil pumps? Hey guys I just got a '85 ATC70 bottom end that I'm about to take apart for the transmission and was wondering if I can use the oil pump to upgrade my z50 stock unit? Does it have more oil flow? Just trying to figure out what other parts I can take from it so I can get all of my money's worth.

07-10-2009, 07:24 PM	#2 (permalink)
kawik01 1st Gear Member Join Date: May 2009 Location: ky Posts: 203 My Mood:	Re: Difference in ATC70 and Z50 Oil pumps? i'd imagine that it would give more flow beacuase bigger motor=more oil needed but you may have to mod the mounts or something

07-10-2009, 07:50 PM	#3 (permalink)
HaiSpeedZ50R PM Newbie Join Date: Jun 2009 Location: Palm Beach Posts: 92 My Mood:	Re: Difference in ATC70 and Z50 Oil pumps? Yeah that's what I figured too but I think I read somewhere about the "drive" apart of it being different. Hmm I wonder if the cases or crank are good for anything?

07-10-2009, 07:51 PM	#4 (permalink)
kawik01 1st Gear Member Join Date: May 2009 Location: ky Posts: 203 My Mood:	Re: Difference in ATC70 and Z50 Oil pumps? i wouldnt know

07-11-2009, 12:35 AM	#5 (permalink)
mexicanyella El rey de los puntos Join Date: Aug 2008 Location: Troy, MO Posts: 984	Re: Difference in ATC70 and Z50 Oil pumps? "Hmm I wonder if the cases or crank are good for anything?" Sure, they're perfectly good for spares. The cases are not ATC-specific other than the serial# stamped in. The clutch cover will have the kickstart hole blanked off, but you can find other clutch covers to fix that issue if you want to build a kickstart motor around one. The flywheel cover will have the pullstart assembly, and a little hole for the gear position indicator spindle, and I'm not sure if the flywheel is the same as a 6V points 2-wheeler flywheel or not once you remove the pullstart cage. The little gear indicator pointer screws into the shift drum and on a bike would normally be a plain bolt covered by a rubber plug. With a bike-specific flywheel cover (and maybe flywheel; not sure if ATC flywheel requires deeper cover or not) and a different clutch cover and the bolt/rubber plug in the shift drum instead of the pointer, you've got a bike engine. Well, in your case I guess you'd need to add a top end and some transmission innards too. I think all ATC70s used the 6V points ignition, and will have a particular taper on the flywheel end of the crank which is different from later CDI motors. But I thiiiiiiiiink that taper will be the same as a 6V points-ignition bike, so it could be a spare for an automatic-clutch 6V points engine. I'm basing this off of examining a '77ish ATC motor I have here. Most of one, anyway. There may be changes to the 80s ones I'm unaware of. Chime in, anyone? Last edited by mexicanyella; 07-11-2009 at 12:38 AM.*

07-11-2009, 01:04 AM	#6 (permalink)
HaiSpeedZ50R PM Newbie Join Date: Jun 2009 Location: Palm Beach Posts: 92 My Mood:	Re: Difference in ATC70 and Z50 Oil pumps? Spares would be nice. . . if I had another atc..hehe. I'm using this bottom end as a donor for my Z50R's 3 to 4 speed conversion. You're right about the gear indicator thingie..other then that I guess it's identical to a 6v 50 motor.

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