[i_play_bass]

Yep the black coating is normal on the SPI pistons. I set my digital caliper to 65mm, locked it in and went around all 3 cylinders at top and bottom. Very tight to the 65 all around on both the spare block and the one that was running. I cleaned up the spare block and it's got the pins and heads in better shape so I'm going to hone the surface rust off the cylinders and hopefully use the spare.

It'll probably be over the summer before I buy the new parts, but I'll get the flywheel off, then pull the rest of the engine out of the bay, get everything cleaned up in the belly pan, and do some of the smaller stuff before tackling the rebuild over the summer

 

[kccats]

My home made is way better than the 3 prev I had!

 

[i_play_bass]

I hope to only have to use mine once a decade haha.

 

[cadillac_al3]

"very tight to the 65 all around": I see we have different standards of precision. Must be close enough

 

[BC_Dan]

I agree, those pistons look like they were after-market with coated skirts.

 

[i_play_bass]

"very tight to the 65 all around": I see we have different standards of precision. Must be close enough

I know some people who are super slack and some who are perfectionists... Which end of the spectrum are you on?

This is my first engine teardown so I'm all ears for how precise this needs to be... Aside from shipping a 25 year old engine halfway across the continent haha.

 

[i_play_bass]

I agree, those pistons look like they were after-market with coated skirts.

Dan, I saw an old comment you made about degreasing/cleaning. Still recommend Simple Green? I'm gonna to get all the 25 year old grime out of the engine bay while it's missing its tenant and give the chipping paint a fresh coat of high temp black. I've got a small bottle of Super Clean but the Simple Green is cheaper.

 

[BC_Dan]

I like it because it pretty much rinses completely with water. I buy the stuff by the gallon. I've used other degreasers but keep going back to Simple Green...

 

[stevem5215]

Those pistons were coated. That's what's left on the sides of them. It's designed to wear off after a period of use. That engines had work done. I'd be cautious as to all clearances, flat head and cylinder deck too. Gasket looks like it was layered up. Maybe a crank job already and maybe even an extended crank. Check everything. Or swap in something less messed around with!

 

[i_play_bass]

It looks like the gasket is three layer manufactured. I don't know much about head gaskets, but it's got coated top layer, bottom layer then a metal layer in between held together with a grommet.

What clearances should I be checking keeping in mind I don't have a full mechanics shop in my garage, just your basic tools and I don't mind picking up a few cheap tools, like I need a honer still.

Also, if doing the oiler mod, where can I find a fitting for the oil line to press into the case once drilled out? I assume it's a different fitting than what runs to the block for fuel mixture by the carbs right?

What should I be looking for on the crank when I get it all apart? I might just take it to the shop that rebuilt my clutch and see if he can tell me how it looks. I'm thinking of doing over the crank bearings anyway while I have it off, but would a person typically swap the interior bearings also or just the outside ones?

I priced things up, cdn dollars:

3 ProX piston kits with rings, pins, bearings and circlips, full winderosa top end gasket and crank seal kit: $345.

PTO bearings (2) & mag bearing: $120

4 line Oil pump: about $120 cdn incl fitting & line

Also going to do my jackshaft & driveshaft bearings. Already have one brand new kit I bought but never put on yet, and kit for both: $50

Honer: $35

My carb boots are in good shape. Nice and soft, no cracks.

$670 taxes and shipping all in gets top and bottom end done, drive bearings all redone. I may need to pick up carb needle and float bowl gasket kits but that's about the only other expense.... Besides replacing my duct tape seat someday I might need someone to pull and press crank bearings and inspect the crank and maybe the block but hopefully that's it.

Correct me if I'm wrong but that seems like a reasonable price to pay (about 530 usd) on that much work/benefit since I'll do it myself?

 

[cadillac_al3]

All you need is a feeler gauge to check the piston to wall clearance. If you can slip a .006" feeler gauge in there you can start to worry a little. I have never taken apart a Fuji with less than .005". That is insanely loose in my book but they seem to run fine for a long time with that much clearance. When I used to race dirt bikes we used to shoot for .0015" clearance and Weiscos needed a loose .003". I would probably let them Fuji pistons go at .006" but that is getting pretty loose. I wouldn't mess with the crank bearings if they turn nice and smooth. If you can't detect any roughness they are probably ok. I have had computer issues and no free time to post lately. good luck.

If you have the extra parts for the oil pump mod then you might as well use them. I wouldn't stress over it. I would just drill out the PTO oil hole like the others and call it good.

 

[i_play_bass]

Ok, I have feeler gauges, so I plan on first checking my ring end gaps with a new set of rings to see how they look, but then for piston clearance do you just measure at the piston head with rings still on between the piston and the cyl?

I'm completely open to whatever mods or improvements can be made while it's all apart. Some swear by the oiler mod, but I need to get the pump for that.

My XLT Touring is with the 34mm carbs, no triple pipes, bone stock. I know the ones that really had issues were the higher performance XCRs and modded xlts, so they tended to burn down more often but I'm all for making mine rock solid whether it be drilling out the current oiler holes or adding that 4th line. Obviously one is cheaper but $100 isn't make or break for me.

 

[BC_Dan]

Here's a video of a guy doing the oil hole mod, it shows why and gives an example. I looked briefly for someone posting the oil pump mod and did not see one. I've never owned an XLT, so have no experience breaking one to rebuild it The vid has a good example of installing the PTO bearings, as well.

Like Coolhand said, if the interior bearings are smooth and turn without any gritty feel, I would not change them. If they are gritty, that would mean a visit to someone who does cranks, and the more, the better. Keeping the crank in phase and in line is really important. When I had my 650, when that engine got new bearings, the place also spot-welded the crank to keep it in phase. But I would want someone doing that work that knows what they are doing.

 

[i_play_bass]

Here's a video of a guy doing the oil hole mod, it shows why and gives an example. I looked briefly for someone posting the oil pump mod and did not see one. I've never owned an XLT, so have no experience breaking one to rebuild it The vid has a good example of installing the PTO bearings, as well.

Like Coolhand said, if the interior bearings are smooth and turn without any gritty feel, I would not change them. If they are gritty, that would mean a visit to someone who does cranks, and the more, the better. Keeping the crank in phase and in line is really important. When I had my 650, when that engine got new bearings, the place also spot-welded the crank to keep it in phase. But I would want someone doing that work that knows what they are doing.

Thanks Dan. I have seen this one, seemed to give a good walkthrough.

I'm ok with replacing parts and such, it's moreso not having the engine experience to diagnose a problem. Last thing I'd want to do is rebuild everything, have something like the crank being an issue and then I've sunk all that $ into fixing nothing. The shop that rebuilt my clutch was a former mechanic at the Harley and Polaris dealership who worked on the sleds for decades. He just branched off to his own bike shop but he's got a great reputation for good work and knowing his Polaris stuff. Might be cheap insurance to take the crank to him to inspect before I sink start buying my rebuild parts. If crank needs any significant work I'm better off doing in a full engine from a 1998/99... Or making the call on whether I cut my losses, sell the parts and buy something different!

 

[BC_Dan]

That is always a hard thing to do.. it's difficult to judge where to stop tossing money into something. Been there, done that. Some times it's not about the money, it's about not letting that ^#%@$ sled get the best of you!

But when it's all over and you are riding it, there's a great sense of satisfaction knowing that what you did is working perfectly

 

[stevem5215]

That reason was why I sent the 87 Plus down the road for $300. Enough was enough ! Time for "better" !

 

[i_play_bass]

Lol yep. If the prices weren't so crazy in my area nowadays I'd consider it even more but I'd be spending 3 grand on something just as old or as poorly maintained, and since our winter here in the Canadian Maritimes only end up being at best 2 months with a few thaws mixed in there, it's tough to justify buying a lot newer or financing what will sit in the garage for 10 months of the year. Quads have limited legal trail systems here so that one's tough to justify too!

 

[stevem5215]

Ha, you think you have it bad in the far north of PEI ! You should try living in the "deep south" of Pennsylvania ! We barely get snow here at all. It really sucks owning a snowmobile let alone being what I like to call "the southern most state with an organized trail system". That's PA . Go any further south and you get basically nothing for snowmobiles even though yes, Maryland has some trails we are organized here more so than them. Ohio, yes has some trails next to the BIG lake but otherwise nope nothing for them. They have to ride in PA or NY or Michigan. Quads here in PA outsell sleds by 7 and 8 times us sledders. And they have basically no trail system other than some organized road riding and "pay as you go" riding parks. No one wants them on any public lands either. State Forestry and State Parks restrict it to only the areas where there's nothing being used. It's pretty sad really.
Anyway, thought I'd just mention it.
Heck, get that sled rebuilt. Run it on the grass some to test it out. I run mine in the fall on the "down and back" I like to call it run to make sure it's working good. Doesn't get too hot doing that one. And it's a good test of the sled.

Steve 14' Zr8000lxr
Check out the pictures on my webpage of the riding too!

Snowmobiling Page by Steve M in Pittsburgh PA

 

[i_play_bass]

Ha, you think you have it bad in the far north of PEI ! You should try living in the "deep south" of Pennsylvania ! We barely get snow here at all. It really sucks owning a snowmobile let alone being what I like to call "the southern most state with an organized trail system". That's PA . Go any further south and you get basically nothing for snowmobiles even though yes, Maryland has some trails we are organized here more so than them. Ohio, yes has some trails next to the BIG lake but otherwise nope nothing for them. They have to ride in PA or NY or Michigan. Quads here in PA outsell sleds by 7 and 8 times us sledders. And they have basically no trail system other than some organized road riding and "pay as you go" riding parks. No one wants them on any public lands either. State Forestry and State Parks restrict it to only the areas where there's nothing being used. It's pretty sad really.
Anyway, thought I'd just mention it.
Heck, get that sled rebuilt. Run it on the grass some to test it out. I run mine in the fall on the "down and back" I like to call it run to make sure it's working good. Doesn't get too hot doing that one. And it's a good test of the sled.

Steve 14' Zr8000lxr
Check out the pictures on my webpage of the riding too!

Snowmobiling Page by Steve M in Pittsburgh PA

Some days I'd take where you live and no snow compared to my bit more snow... I've been a HUGE Pens fan for over 30 years now, since I was a little feller! 66 is my hockey hero. Only player jersey I own.

 

[cadillac_al3]

Ok, I have feeler gauges, so I plan on first checking my ring end gaps with a new set of rings to see how they look, but then for piston clearance do you just measure at the piston head with rings still on between the piston and the cyl?

I'm completely open to whatever mods or improvements can be made while it's all apart. Some swear by the oiler mod, but I need to get the pump for that.

My XLT Touring is with the 34mm carbs, no triple pipes, bone stock. I know the ones that really had issues were the higher performance XCRs and modded xlts, so they tended to burn down more often but I'm all for making mine rock solid whether it be drilling out the current oiler holes or adding that 4th line. Obviously one is cheaper but $100 isn't make or break for me.

IMO you can't do anything until you know if it needs a re-bore or not.; to buy pistons or not to buy pistons. The cheap easy way is the feeler gauges.. Slip in in from the bottom side and with the piston an inch down in the hole. That will give you a close enough ballpark figure. It has aftermarket pistons so it could already be overbored with nice tight pistons or somebody just slapped new pistons in worn bores just to sell it. If it already has tight pistons, that won't explain why it ran like crap. If they are loose pistons then maybe that could be a cause. If they are tight then all you need is a gasket kit. If it's low miles I wouldn't even split the cases. If it is 10k miles or so then I would at least change the crank seals and drill the pto oil hole since it's already apart.