06-14-2010, 09:50 PM #1
SBT cylinder exchange program review
Well after many people saying "dont do it" "sbt is crap" and what not, i was worried since i had already placed an order for a 1200pv cylinder exchange. If your not farmiliar with how the program works they send you a re-sleeved cylinder (they bore the oem nikasil plated ones out and press in sleeves) and a matched piston and ring kit, plus all the gaskets needed. Now i would like to say some things about SBT in general, but before i get started i just want to make it clear, I AM NOT SAYING SBT IS WONDER FULL! This is my only experience with them and i noticed they don't have the best track record, i can only speak for mine.
Now with that out of the way, i placed my order on a Friday with a friendly woman who told me the cylinders were in stock but not re-manned yet so it would be 5-7 days before they shipped, but happily they showed up the Wednesday after! They either slammed them out and shipped them Friday, or just had them in stock and didn't know. Either way, when it got here they threw in extra gaskets, i was told id get just the manifold gaskets for both sides, and the base and head gaskets. However i got a full intake, exhaust, and top end gasket kit, with extras in each. Very cool
The gaskets were different, but fit the same and work just fine. Now onto the cylinders, i noticed there was a lot of people saying there ports don't line up and/or aren't chamfered. And they may appear to not be chamfered but they indeed are, 30 degrees in fact. The ports line up 90 percent perfect, which is good enough and the transfer ports now are a MARGIN smaller since they are cut in half by the sleeve in 2 spots. Anyone concerned about the power loss from this tiny difference should probably not be running this setup anyway so that's out of the picture.
Moving onto the bore, i measured the bore in 6 spots with an inner mic, sorry i didnt take pictures i was too excited to put it together. However it checked out none the less when i measured the piston and calculated the piston to cylinder clearance called out by sbt to be .0045-.0055" if i remember correctly.
The only issue i had with quality did upset me a bit, there was a missing restrictor in the water jacket of one cylinder (assuming that's what they are) but i just took one out of mine before sending them back and let sbt know which was not a problem, but what upset me was that the other two were barely tight and without any loctite to stop corrosion. Maybe im just anal but i would have expected it to be done.
They sent new piston pins and wrist pins with the pistons and cir-clips obviously and once it was all together i rebuilt my power valves and carbs (with an issue or two that have been sorted out thanks to beerdart) then fixed a few other issues that needed attention in the hull. By the way my crank checked out OK so i didn't replace it.
The moment of truth went well as i expected, just a little hard starting with dry fuel lines (want a primer kit) and i broke the motor in according to sbts guides plus a little of my own theory on it im running 32:1 yamalube premix with hardly any smoke, no loading up either so ill stay 32:1 but experiment with oil brands. The motor is a little noisy but it was before too.
NOW, my impressions after break in, i thought initially that the different port sizes might have been ruining my power band since 4200-5100 rpm was un usable it kept falling in and out of power band, but i discovered i forgot to adjust the free play on the yvps cables tighter, and ordered some wave eater couplers to take the rest of the slack out, and hope that fixes this as its already much better. The motor has a lot of punch and still turns max rpm, no mechanical problems to report yet, and i don't expect any. The sbt gaskets held just fine too.
So all and all i have had no major issues, and hope to get a long life out of my top end, i know some people are concerned about a cast iron sleeve not dissipating heat as well, but i find this very hard to believe that the cooling system cant keep up with the marginal extra retained heat. Either way ill be reporting back mid way and all the way threw summer, and fallowing up with a compression test result in a few days once i run one more tank through it.
SO to sum my rant up
-The exchange program for me worked out GREAT
-No major issues
-Great customer support
-Pretty good build quality
-EXTREMELY cost effective considering prices of oem stuff, your getting a NEW bore and piston to match which is the best and most reliable way to rebuild instead of using an old tapered out of round worn bore with a new piston
-Did i mention cost effective?
Feel free to ask questions!!!
06-14-2010, 09:51 PM #2
AND! A thanks to lee carson for the help with the yvps as well as beer dart for holding up the trip a few mins while my lost ass found your house haha
06-14-2010, 10:12 PM #3
Yeah ive been around the block with motor builds a few times, this is my second hobby, my m3 is my main lol. Used to race motocross too, so im not new at it, i think the issue with the sbt motors could be there "techs" that put them together. I trust my work, and i checked theres before i slapped it together. On another note my good friend has a gp760 with an sbt motor in it and has 20 hours on it so far without an issue, lets hope for his sake itl keep it up.
06-14-2010, 10:36 PM #4
06-14-2010, 10:58 PM #5
Ive been building skis for almost 20 years and bikes even longer. I bought my first two sbt long blocks back in about 2000 when a guys gtx limited and xp limited both gernaded cranks-it just wasnt economical for me to build a new crank-repair cases etc. I have had good luck with there top end exchange program(i currently run a ski rental and can usually get the kit faster than waiting to get my cyl bored). Only issues ive run into are small ones on complete long blocks. Ive bought a couple used skis with sbt long blocks and bought a couple long blocks myself and I always dissasemble them-buy anouther gasket kit and reassemble them. Ive found rotary valve seals installed backwords-crank seals in backwords-piston pin clips not seated in the groves and so on. So my advice is to always just check and recheck the small details yourself before installing there motors-but ive never had a problem with there parts or machining.
06-15-2010, 12:11 AM #6
06-15-2010, 08:40 AM #7
Glad to help. Now we need to ride... For payment get me a Sunnyside Sticker
06-15-2010, 06:38 PM #8
+1Glad to help~! Keep us updated. Lee
06-15-2010, 09:58 PM #9
06-15-2010, 10:24 PM #10
- Join Date
- Oct 2009
- Green Cove Springs Florida
My inlaws had an oil line drop off thier xl800 and after a teardown, decided to go with the SBT cyl exchange also. I would agree that the customer service was great and the ease and quickness of the exchange with the included shipping and fed-ex pickup at your house, it's about as easy as it gets. No major issues with the parts other than a couple of small burrs from what looked liike the sleves being installed which we removed and cleaned. We've had the ski out a handfull of times with about 15+ hours on it and it runs like a champ. My only real gripe was that it came with all the same gaskets and mentioned above but didn't come with PV gaskets which have to be removed to install the kit bit included a couple of exhaust gaskets which were not needed. Just my expierience.
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