900 jugs on 800 crank

custom polaris 600 · Jan 20, 2012

Has anybody put a 900 top end on a 01 800 bottom end. I burnt a piston a am thinking on building it while im in there. If some one has what thing to look for and what thing did you have to do to make work (trimming case ect.)

G-man · Jan 20, 2012

should bolt right on. They both use the same bottom end. Just finished rebuilding one of each and have a 1010 D&D on an 800 bottom end. Just have to change jeting on carb models. Not sure on the EFI models if the ECU needs a diferent map. I would cross check part numbers if EFI.

kidrman · Jan 20, 2012

No 800 EFI until 2002.

Idcatman1 · Jan 21, 2012

If your 800 cylinder is toast they can be bored and replated to take the stock 900 piston. I wouldn't go any bigger than that because the bridge between the main exhaust port and the boost ports gets really thin and will crack. I have seen 800 cylinders bored to 1010 and there isn't much left of that bridge.

Booster · Feb 13, 2012

It also helps to swap to bigger pistons for the larger cylinders too, just to keep the rattling to a minimum.

Idcatman1 · Feb 14, 2012

Yes, pistons to fit the bore is always a great idea. Helps with compression also. One thing that hasn't been mentioned is the exhaust valves. If you bore 800 cylinders the stock 800 ones can be ground to fit. If you use 900 cylinders you will need the 900 valves. They are just enough different that the 800 ones will not work in a 900 without a lot of work. Hope this wasn't too confusing.

triedit · Feb 14, 2012

800

need to cut the head for the bigger pistons

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900 jugs on 800 crank

custom polaris 600

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G-man

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kidrman

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Idcatman1

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Booster

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Idcatman1

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triedit

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