installing a new powerhead
01-31-2009, 04:37 PM
#1
Thread Starter
installing a new powerhead
I want to install a new stock powerhead on my Zenoah 260 . Do I need to heat the head up in the oven before it will slip over the piston ? If I do what temp. does it need to be ? I did a search but couldn't find anything on that topic .
01-31-2009, 06:22 PM
#3
RE: installing a new powerhead
Heat is never needed.
In short - Align the head the right way relative to the crank. Make sure you have your gasket in place. Line up the piston ring with the locator pin in the ring groove. Compress the ring into the groove with the fingers of one hand and slide the cylinder on with the other. Dont force it - it should slide with minumal resistance if the ring is compressed. NEVER rotate the cylinder once you are over the ring as you will break the ring.
In short - Align the head the right way relative to the crank. Make sure you have your gasket in place. Line up the piston ring with the locator pin in the ring groove. Compress the ring into the groove with the fingers of one hand and slide the cylinder on with the other. Dont force it - it should slide with minumal resistance if the ring is compressed. NEVER rotate the cylinder once you are over the ring as you will break the ring.
01-31-2009, 06:22 PM
#4
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RE: installing a new powerhead
Dana, are you installin' an m5, or is that the replacement for the one w/ the stripped spark plug hole? BTW, what is that NGK plug#? I also cannot stand Champion spark plugs, unless it's for the mower!-CE
01-31-2009, 06:47 PM
#6
Thread Starter
RE: installing a new powerhead
I bought a new stock zenoah from WWH . It came with a Champion plug , I hate Champion so I went to remove it and it came out 1/4 turn then stopped . I knew I was in trouble but needed to remove it . The top threads of the cylinder was stuck to the plug . I emailed Tony at WWH and he said ship the head back and he will replace it at no charge . Now I'm ready to reinstall it . I figured someone here could give me some good tips since I'm not an engine guy 
) . Thanks for all your tips , I'll see what I can do .
) . Thanks for all your tips , I'll see what I can do .
01-31-2009, 08:03 PM
#7
Thread Starter
RE: installing a new powerhead
I can't see how this is going to fit . I took my digital calipers and measured the outside walls of the piston and it's 33.91 . The inside walls of the cylinder is 31.90 . I'll call Tony on Monday . I may just ship the whole thing back . Or is it possible I received a 230 head instead ?
01-31-2009, 08:36 PM
#8
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RE: installing a new powerhead
I have one in bits, cylinder diameter on a 260 is 34.1mm. (approx- I used vernier calipers too)
Piston is a sahde under 34mm.
Seems you have a problem there. I find they go in pretty easy when they are right, just squeeze the ring in nice and easy when it is over it's pin and it goes into the cylinder nicely.
Glenn
Piston is a sahde under 34mm.
Seems you have a problem there. I find they go in pretty easy when they are right, just squeeze the ring in nice and easy when it is over it's pin and it goes into the cylinder nicely.
Glenn
01-31-2009, 08:42 PM
#9
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RE: installing a new powerhead
Sounds like a 231 cylinder at 32mm bore, the 260 is 34mm.
[link=http://zenoah.net/products_hobby.html?tbl]Zenoah specs.[/link]
[link=http://zenoah.net/products_hobby.html?tbl]Zenoah specs.[/link]
01-31-2009, 09:01 PM
#12
Thread Starter
RE: installing a new powerhead
GEEE's I bought this engine on sale . Now it seems I'll pay more in shipping twice then if I would have just paid the regular price . Thanks for clearing that up for me .
