just acquired a redmax 8001 with blown piston, couple questions

kilabeez0

LawnSite Member
Hello, noob here. Ive rebuilt a few motors in my day so I'm familiar with the process. My neighbor owns a landscaping company and I was helping him out doing fall cleanups when one blower wouldn't start after shutting it off. The next day we started it in the morning and just let it run for 6 or 7 straight hours because we needed to get through the day :laugh: Anyway it finally stopped running and he offered it to me for cheap. We haven't figured a price but I might just work a few hours for him in exchange.

I pulled the top end off and saw the piston had melted an indent in the middle and had cracked along the dome. The cylinder seems ok but I need to get a look in better light. So far I have a list of of about $30 in parts and $10 shipping which consist of a piston, 2 rings, pin, and base gasket from redmaxpartsdirect.com

I was going to reuse the circlips on either end of the pin and hopefully the cylinder and be in this for cheap money. My question is would you recommend the wrist pin bearing and keepers or should they be ok? Any tips I'd appreciate. Like I said I've rebuilt motors but mostly 4 strokes and a couple snowmobiles. Thanks in advance:drinkup:
 

BigFish

LawnSite Fanatic
Location
chesapeake, va
NEVER ever re-use piston pin clips! I would replace the bearing, why not?
A tip, when you install the clips, make sure the opening faces the piston crown.
 
OP
K

kilabeez0

LawnSite Member
i hear u on the pin clips lol. i'll get those. bearing is another 10 bucks not including keepers. i was just trying to go as cheap as possible. :hammerhead:
 

dutch1

LawnSite Silver Member
Location
Jayhawk
There's nothing wrong with trying to the job as cheaply as possible but if you want the rebuild to last, don't leave any stones unturned. Take a good look at the jug and the needle bearing on the crank/rod. If the piston actually did melt it's likely a result of a lean running condition, an improper mix ratio or a poor quality oil.
 
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kilabeez0

LawnSite Member
I mean if the needle bearing has no slop or play it should be good no?
Posted via Mobile Device
 

dutch1

LawnSite Silver Member
Location
Jayhawk
Do as Fish says, replace the piston pin bearing.

The crank/rodbearing is another story as the crank/bearing/rod is sold as an assembly and will be pricey. If there isn't any excessive play, I'd say you're good to go.
 

RickyDL77

LawnSite Senior Member
just some advice, after you get it running again, dont go cheap on gas and 2stroke oil.. those models in particular are very picky.. 300+ redmax units, 40 of those the EBZ8001RH models and 2/3 of those burnt the pistons just as your newly aquired unit has. the guys use regular unleaded 10% ethenol fuel and regular none synthetic oil. all the other units seem to do fine just the EBZ 7001-8001 models and the 8001 in particular.

Perhaps redmax got skimpy on the thickness of those pistons, nonetheless they state mid grade fuel or better and their synthetic blended oils for best results and to avoid voiding warranty.

one other note, make sure it is not running to lean. if it was not the fuel... then something caused it to overheat and melt the piston.
 

ed2hess

LawnSite Fanatic
just some advice, after you get it running again, dont go cheap on gas and 2stroke oil.. those models in particular are very picky.. 300+ redmax units, 40 of those the EBZ8001RH models and 2/3 of those burnt the pistons just as your newly aquired unit has. the guys use regular unleaded 10% ethenol fuel and regular none synthetic oil. all the other units seem to do fine just the EBZ 7001-8001 models and the 8001 in particular.

Perhaps redmax got skimpy on the thickness of those pistons, nonetheless they state mid grade fuel or better and their synthetic blended oils for best results and to avoid voiding warranty.

one other note, make sure it is not running to lean. if it was not the fuel... then something caused it to overheat and melt the piston.
I was surprised at the low cost of the piston and.....how in the world did a piston melt down and not damage more stuff?
 

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