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Discussion Starter #1
Changed the top end on our 87 a few weeks ago, by choice not necessity. After an easily 400+ hour life, here's how good the piston looked. That was right as I pulled the jug off, no wipe down, no clean up of any sort. Cyl wall was just as clean. A new set of rings would've done it if I wouldn't have had my heart set on a completely fresh top end for that bike.

 

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wow looks good, you do a comp test? just curious to know what it started at and what made ya decide to tear down..
 

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wow looks good, you do a comp test? just curious to know what it started at and what made ya decide to tear down..
It started at 185 in 2006 and that was the last compression test for that top end. Periodically it was torn down for preventative maintenance, cleaning or replacing powervalves, etc. The rings were always within spec and everything looked good so back together it went. One of those teardowns, we even split the cases and replaced all the bearings and seals down there, checked crank balance, etc. Top end was reliable (read: bulletproof) and still looked good still so back on it went. I decided to replace it this time because it was starting to feel a little sluggish. Part of that was a faulty powervalve. Other reason is there's been a nice ported cylinder with fresh bore, new piston and a few rare pipes out in the garage that have been asking to get put on and tested.
 

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Discussion Starter #6 (Edited)
Thanks climb, I agree it still looks pretty healthy. It'll stay in the trailer as a spare in case we ever need it at the beach.

It's always been fed 92 octane mixed at 40:1 and sprayed through a 38mm Lectron. 2006 and 2007 I ran Maxima 927 in all the bikes because I do prefer the castor oil. Unfortunately it was gumming up the powervalves on the T4s and I was fed up with breaking them monthly. It was then that I switched to Maxima Super M. It's been great. All the bikes play well with it, it doesn't break powervalves and it doesn't foul plugs. Combined with proper tuning and maintenance I expect to continue getting these results.

I'll round up a pipe pic for you climb
 

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No I don't. The gumming up is THE REASON why castor based mix oil works so well these engines. It creates that gummy film that protects so well when warmed up. When its not hot enough, it prohibits the powervalves from turning and then they snap. If we ran the engines in the higher rpm more often, the gum would take longer to accrue. Since we don't, we'd have to clean the pv's after every trip to keep from breaking them. When Maxima Super M provides just as good of protection for our riding conditions without all of the fuss its an easy choice for me.
 

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How would you rate your lectrons compared to other carbs? I have a lectron distributor a couple minutes away.
 
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