Planet Minis

mxracer49 · 07-25-2008, 08:48 PM

Was having problems with my kids' 70. I went ahead and tore it completely down tonight.

Ordering a new top end gasket kit, high volume oil pump, 52mm ring set (88 kit). Putting in new valve guides. Going to lap the valves also. Heavy cam chain and getting an aftermarket cam.

I need the 2 small 17mm bolt on valve covers. I haven't seen these on any of the sites except dratv but it says they are for 50s. I need a cam sprocket bolt also. I can probably get this at the hardware store but just in case. Haven't taken the flywheel off yet going to do that tomorrow. May as well go in there and see if anything shows signs of wear while I have the motor out.

So if anybody has any of these parts they want to get rid of let me know or turn me on to some online deals.

Thanks
Darin

firepower354 · 07-25-2008, 09:13 PM

The new guides are likely to need to be reamed to size once installed, then the seats cut to match. I've seen several 70 heads with worn guides, but 50's seem to last forever

Might be cheaper/easier to get a deal on a TB/E22/etc head???

70 pump is higher volume than the 50 pump. 50 covers and cam bolts are the same as 70's. Might want a cam chain, for peace of mind.

mxracer49 · 07-25-2008, 10:31 PM

I'm confused. Are you saying the valve guides are not just a quick replacement part? I'd really like to stay with the stock 70 head and go with a larger cam. But if worst comes to worst I suppose I could just get an E22 from dratv for 88 bucks. Not real thrilled about that, though.

Then you say the 70 oil pump is higher volume than the 50 pump. Am I wasting my money buying a high volume pump? Should I just stay with the stock 70 pump with the 88kit?

firepower354 · 07-26-2008, 06:46 AM

Correct on the guides. Not a drive out-drive in deal. I really like the 70 head, once ported to remove the bowl machining steps and the runner pinch. Maybe the guides would be ok with new valves?

I feel the 70 pump is plenty, but it's not much money for a HV, and shouldn't hurt anything.

07-25-2008, 08:48 PM	#1 (permalink)
mxracer49 1st Gear Member Join Date: Oct 2007 Location: Kansas Posts: 111	Need a couple stock XR70 parts Was having problems with my kids' 70. I went ahead and tore it completely down tonight. Ordering a new top end gasket kit, high volume oil pump, 52mm ring set (88 kit). Putting in new valve guides. Going to lap the valves also. Heavy cam chain and getting an aftermarket cam. I need the 2 small 17mm bolt on valve covers. I haven't seen these on any of the sites except dratv but it says they are for 50s. I need a cam sprocket bolt also. I can probably get this at the hardware store but just in case. Haven't taken the flywheel off yet going to do that tomorrow. May as well go in there and see if anything shows signs of wear while I have the motor out. So if anybody has any of these parts they want to get rid of let me know or turn me on to some online deals. Thanks Darin

07-25-2008, 09:13 PM	#2 (permalink)
firepower354 3rd Gear Member Join Date: Oct 2006 Location: Flint MI Posts: 6,255	Re: Need a couple stock XR70 parts The new guides are likely to need to be reamed to size once installed, then the seats cut to match. I've seen several 70 heads with worn guides, but 50's seem to last forever Might be cheaper/easier to get a deal on a TB/E22/etc head??? 70 pump is higher volume than the 50 pump. 50 covers and cam bolts are the same as 70's. Might want a cam chain, for peace of mind.

07-25-2008, 10:31 PM	#3 (permalink)
mxracer49 1st Gear Member Join Date: Oct 2007 Location: Kansas Posts: 111	Re: Need a couple stock XR70 parts I'm confused. Are you saying the valve guides are not just a quick replacement part? I'd really like to stay with the stock 70 head and go with a larger cam. But if worst comes to worst I suppose I could just get an E22 from dratv for 88 bucks. Not real thrilled about that, though. Then you say the 70 oil pump is higher volume than the 50 pump. Am I wasting my money buying a high volume pump? Should I just stay with the stock 70 pump with the 88kit?

07-26-2008, 06:46 AM	#4 (permalink)
firepower354 3rd Gear Member Join Date: Oct 2006 Location: Flint MI Posts: 6,255	Re: Need a couple stock XR70 parts Correct on the guides. Not a drive out-drive in deal. I really like the 70 head, once ported to remove the bowl machining steps and the runner pinch. Maybe the guides would be ok with new valves? I feel the 70 pump is plenty, but it's not much money for a HV, and shouldn't hurt anything.

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