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Discussion Starter · #1 ·
I got my XCR 800/ edge apart (compression on the low side at 125 per hole)I don't have any experience with these motors yet. The cylinder and pistons look great for 6000 plus miles. Doug flanery did some nice trail porting.Anyhow Im going to take it all the way down and rering it but I don't see any markings on the pistons except for a 79c are these a Polaris piston or after market so I can make my Polaris order complete with the right rings.Any other advice on what else I should replace after a Polaris manual inspection outline.Thanks in advance for any advice.
 

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at that many miles I personally would just get new pistons as well,

for base gaskets i would get cometic rubber coated steel ones, they are cheaper and far better than the paper from polaris, as well as reusable.

personally i would send the cylinders out for a hone job and inspection. there could be a good chance that they are a little out of spec and 1 of them might need a rechrome.
 

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Discussion Starter · #3 ·
yeah the more Im thinking about it new pistons are the way to go why take the chance to much money if a skirt is going bad plus allot of fatigue on them.Do you have any suggestions on a good place to have the cylinders checked and rechrome if needed.I have a dail bore gauge and a ball hone the chrome appears to have no scrathes or ware marks. Do these cranks have problems like the bigger twins.Im also replacing the green slides polaris list a part as 3131252 is that right.I think the oil lines and fuel lines could need replaced.The t they use for the center and pto bearings looks like its lacking oil any mod on this .If I have this thing apart I dont want to miss anything . THX
 

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650indy1 said:
yeah the more Im thinking about it new pistons are the way to go why take the chance to much money if a skirt is going bad plus allot of fatigue on them.Do you have any suggestions on a good place to have the cylinders checked and rechrome if needed.I have a dail bore gauge and a ball hone the chrome appears to have no scrathes or ware marks. Do these cranks have problems like the bigger twins.Im also replacing the green slides polaris list a part as 3131252 is that right.I think the oil lines and fuel lines could need replaced.The t they use for the center and pto bearings looks like its lacking oil any mod on this .If I have this thing apart I dont want to miss anything . THX
if you have a bore guage then just get the piston clearance from polaris, measure the bore and then measure your new pistons,

i deal with millennium technologies, have had very good luck and its only 15 dollars a cylinder for a hone and inspection.

the cranks are a very solid crank other than normal wear, i would have it checked, welded and trued since you have it apart.
 

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Discussion Starter · #5 ·
madcow said:
650indy1 said:
yeah the more Im thinking about it new pistons are the way to go why take the chance to much money if a skirt is going bad plus allot of fatigue on them.Do you have any suggestions on a good place to have the cylinders checked and rechrome if needed.I have a dail bore gauge and a ball hone the chrome appears to have no scrathes or ware marks. Do these cranks have problems like the bigger twins.Im also replacing the green slides polaris list a part as 3131252 is that right.I think the oil lines and fuel lines could need replaced.The t they use for the center and pto bearings looks like its lacking oil any mod on this .If I have this thing apart I dont want to miss anything . THX
if you have a bore guage then just get the piston clearance from polaris, measure the bore and then measure your new pistons,

i deal with millennium technologies, have had very good luck and its only 15 dollars a cylinder for a hone and inspection.

the cranks are a very solid crank other than normal wear, i would have it checked, welded and trued since you have it apart.
 

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Discussion Starter · #6 ·
Thx for all the info can I PM you with just a few more questions The 2001 polaris performance manual glosses over the xcr 800
 

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I just got my XCR apart today, green carb slides, PTO side was broke, luckily the piece was stuck in the reed cage and didnt enter the motor... My sled has 130, 133 and 138 in each hole.... thought that was pretty good for the triple?
 

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Discussion Starter · #8 ·
mdmaniac said:
I just got my XCR apart today, green carb slides, PTO side was broke, luckily the piece was stuck in the reed cage and didnt enter the motor... My sled has 130, 133 and 138 in each hole.... thought that was pretty good for the triple?
Ive heard of these problems with the green slides thats why Im replacing mine with the black ones. Are your carbs on the 600 38mm? The compression on yours sounds good but Ive heard they shouldnt vary more the 10% but Im not sure so many different opinions.One my reeds dont look good it has v force ones hard to find replacement pedals.Might go with the three's but some say they arent as good as the older for triples
 

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V-force 2 are a little hard to find, but v-force 3 replacement petals are available all over.
 

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on the xcr 800 going from stock to v-3s noticed nothing different, the xcr 800 already has to much of a good throttle response to feel any differences.

the biggest thing you can do is sharpen the transfer bridges on the bottom of the cylinder on each side, there is a little casting that goes from the cylinder to the wall, put a knife edge on that. that is usually worth 1-2 grams in the primary and a little gain in throttle response, dropping the stock heads .009" and advancing timing 1-2 degrees at the stator plate really help make some more power and snap. premium gas only then.
 

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Discussion Starter · #11 ·
madcow said:
on the xcr 800 going from stock to v-3s noticed nothing different, the xcr 800 already has to much of a good throttle response to feel any differences.

the biggest thing you can do is sharpen the transfer bridges on the bottom of the cylinder on each side, there is a little casting that goes from the cylinder to the wall, put a knife edge on that. that is usually worth 1-2 grams in the primary and a little gain in throttle response, dropping the stock heads .009" and advancing timing 1-2 degrees at the stator plate really help make some more power and snap. premium gas only then.
the cylinders have been ported and the transfer bridges cleaned they checked out with no taper Im just waiting for the new pistons to check all the clearances I have already ordered the cometic gaskets here are some pics of the cylinders 2010322161312535_21419.jpg
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sharpen that little bridge up, make it knife sharp. dont look like any work has been done,

on the top picture you see the little rectangle, chamfer both side all around on that little port.

on the bottom picture where its white and opens to the ports, take about a 1/16 off of that area.
 

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Madcow, would you want to polish as well? Take all that rough casting surface and smooth it out to allow air to flow past it without disturbance?

Or do you want the disturbance to keep the atomized fuel suspended?

I know with cars you want them smooth, but 2-strokes are a different beast.
 

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Ugly_old_Poo_kid said:
Madcow, would you want to polish as well? Take all that rough casting surface and smooth it out to allow air to flow past it without disturbance?

Or do you want the disturbance to keep the atomized fuel suspended?

I know with cars you want them smooth, but 2-strokes are a different beast.
if you do the exhaust ports you want them polished super smooth... not shure on the intake tho.
 

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Discussion Starter · #15 ·
also how about someone who can rebuild the water pump on the xcr 800 and is the part number for the black slides correct 3131252 THX for the porting info these mods keep it trail still right
 

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Black slide part number is correct, I have the 800, I believe it also has the 38mm. Mine has VF2 reeds but so far thats all that looks non-stock.
 

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it will be very trail friendly, if you dont drop the heads and keep timing the same you will be safe for 87 octane.

i am not home to be doing shop work. but this winter i might be home at some point.

the intake doesnt have to be polished, just get rid of any lips or edges that air can hit.
 

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Discussion Starter · #18 ·
madcow said:
it will be very trail friendly, if you dont drop the heads and keep timing the same you will be safe for 87 octane.

i am not home to be doing shop work. but this winter i might be home at some point.

the intake doesnt have to be polished, just get rid of any lips or edges that air can hit.
Im waiting for some porting tools (burr set and abrasive tapers)
It looks like the transfer ports have been raised. I cant tell I dont have a stock cylinder to compare it to.The crank seems to be with in spec for run out.The case has had some work done to it but there is one think that concerns me take a look at the pics see what you think (its the top pic where they ported to what looks like a dowel pin hole but the cylinders dont have pins).What manual do you like for xcr's this edge chassis has a 2001 motor in it.I have the 2001 polaris performance manual and it covers many models but it glosses over the xcr.Any info is highly appreciated THX 2010328175923490_21419.jpg
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in the second picture down, look by the crank, see how the case goes over the crank, that little lip you can straighten that out and round it off better.

raising the intake ports is the last thing and dumbest thing to do on an 800 xcr, they are tall enough from the factory to spin 10grand with the right pipes.

the exhuast port can be raised about a mm and widened some if you want to port something, for the case and bottom of the cylinders open them up and then match.
 

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Discussion Starter · #20 ·
Ok I got the tools for some cylinder cleaning.I sharped the transfer bridges and started to polish and port the exhaust to match the gasket.It went pretty smooth just have to take it slow as not to take off to much material.With this little clean up is re jetting necessary. 201044192611104_21419.jpg
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