Viper Blow-by

I used a three stone flex hone that I rented from Auto Zone. It worked good and did better than a scotch brite pad can do. I dont think it took any material away either. I'll post the compression numbers after I assemble it. The new ring end gap was around .015 so its a little tighter. I'm not gonna baby it this time.
 

Mac said:
Heres a link to ebay for a 320 grit ball hone.
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Mac...
daman said:
Do not use a Ball type flex hone...

ball hones are junk and they dont cut evenly in a 2 stroke, the balls flex in and bounce off the sides/edges of the exh port and transfer ports, you get a much better job with a 3 stone spring flex hone..
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The finger hone worked fine. Its alot softer than the plating. The cylinders are fine with a cross hatch at about a 25-30 degree angle. Just about to bolt on the head, than I'll do a compression test.
 
you wont get a true reading on compression until you get the rings set in to the grooves in the cylinders. so expect it to raise from 5-15 psi.
 
Well right now the PTO is 115, center-135-mag-145, just assembled. The mag had some coolent in the crankcase which is now burned out now, I'll do another reading when cool and recheck. It started in 2 pulls and smoked like a biatch with all of that coolent in the crankcase, but all is well now and no leaks.
 
sxr_700 said:
Well right now the PTO is 115, center-135-mag-145, just assembled. The mag had some coolent in the crankcase which is now burned out now, I'll do another reading when cool and recheck. It started in 2 pulls and smoked like a biatch with all of that coolent in the crankcase, but all is well now and no leaks.
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You running yamalube right now?
 
Ahh I believe there might be some left in it, I ran it low then switched to amsoil interceptor. I would think they will still seat just fine, I gotta put it under a good load (wide open burst, hills, deep snow etc) My bikes have been fine with using synthetic to break in a fresh topend. Infact my YZ250 is pushing 250psi with nothing done to it other than a wiseco topend.
 
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cold compression pto 115 center 135 mag 135, they should go up more when there seated as redsnake 3 said.
 
How do you check for blow-by? I just replaced the head on my viper and noticed the cylinder walls were a very dark brown and there was some very light scratching. I wasn't able to catch a fingernail in any of the scratches so I didn't worry much about them. I did however do a compression check post head swap. I got 125, 125, 125 with 22cc domes and ~.060 squish on all three. I thought that was OK? Now I am thinking I should pull it back apart? Sled is an 04 Viper ER with ~5000 miles on it. Here is the compression tester I used, it has a rather long hose on it so I attributed the lower numbers to that.

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JeepTherapy said:
How do you check for blow-by?
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Either a leak-down test will give you and idea or looking
at the pistons for dark spots down the sides of the pistons,eather
pull the exhaust off and look threw the port or pull the pistons.

but if you got 5k on her stock you'll have some blow by..
 
Well I pulled my head back off to take a new look at my cylinders. Snapped a couple pics while I was at it. I took a clean rag saturated with some sea foam and wiped out the cylinders. I was amazed at how good they looked after simply cleaning them off. They went from the nasty brown scratched look to relatively clean silver with a nice cross hatch pattern. I have decided that I have no fears as to the condition of my cylinders anymore. I was afraid they needed to be re-plated. I am going to run it as is this year and see where I am at for next year. Lord only knows what I will want to do with it at the end of this season if we get enough snow to get some riding time in.

I did however find the condition of the exhaust ports somewhat perplexing. Can someone explain the difference in appearance between the manifolds? All three cylinders have the same jets 165/55. The motor has only been ran at an idle with those manifolds, jets and pipes installed. Is that an indication that my pilots are too big on the center and too small on the PTO? I didn't think the pictures are good enough to show blow by on the pistons?

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Them cyl's are pretty darkened and carbon'd,you sure you don't have allot
of blow by? what kind of oil you run?

my cyl's have never looked that brown(from what i remember)..
 
I have ran yamalube in it since day one, and no I don't know how much blow by it has. Learning as I go here and looking for help when I need it. Do you think I have further issues that are causing the dark cylinders? This is the first time I have had a 2 stroke apart.

Also, if my rings were to the point where I have major blow by wouldn't that also drop my compression dramatically?

Oh, one other thing. Last time it was run I pulled the oil cable all the way open to fill it with oil to store it. Would that have a bearing on how they look?
 
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If you ask me that looks like blow by, i'd throw some rings in the ol girl.

can you look through the exhaust port with a flash light and see the piston?

look just bellow the ring lands for dark spots down the piston
 
If you would have used KLOTZ your motor would NOT LOOK that way!!! YES!!!! It's time for a RINGJOB!!!!!! By the looks of those cylinder walls,,,, It looks like it was time for a ringjob a few THOUSAND MILES AGO!!!!!... I am sorry if I appear to be a little rough on you,,,,but,,,,,nevertheless,,,,,a RINGJOB is in order.. I AM NOT going to recommend the type of HONING or cleaning up of the cylinder walls because of some discrepancies between myself and others on this forum,,, but I CAN SAY that SYNTHETIC lubricants MAKE RINGS last longer!!!!! Gary Oles nosboy
 
Do a little reading on the website www.brushresearch.com and read about the nikasil cylinders BEFORE you take different guys advise on how to clean up the cylinders!!!! CHECK a few websites on other types of hones and see for yourself.. Personally, I would rather see a hone RADIUS a transfer port edge that SHARPEN IT!!!! maybe spun around 200rpm's !!!! JUSTMY OPINION GUYS!!!!!
 
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