|
|
Post by iwiketuddlz on Oct 15, 2015 20:12:00 GMT -5
Darn man I hate that for ya .... It does seem that 14lb is a bit much sometimes when I torque heads and stuff I kinda tense up ever time!!!
|
|
|
|
Post by oldgeek on Oct 15, 2015 20:15:29 GMT -5
Surprisingly even to me I did not get mad, it was more like a oops! At worst, it was a $125 USD mistake as the streetrace kits price have come down a bit. I don't really think its that big of a deal, but I could be wrong. I was glad to hear moofus02 has one similar and it does not seem to hurt anything. I dont think sealing it up will be a problem at all, however I guess it could cause a hot spot and eventually cause a sealing issue? I may try to braze it or something as Corrosion suggested, but I will have to research joining cast iron. IMO it really does nothing but provide cooling to that area. |
|
|
|
Post by tsimi on Oct 15, 2015 20:16:52 GMT -5
I torqued my BBK with 10ftlb(14Nm) since that is what it said in the Yamaha service manual. And so far all is good.
|
|
|
|
Post by oldgeek on Oct 15, 2015 20:31:43 GMT -5
I have always torqued them to 15ftlbs. I have a nice craftsman torque wrench that starts at 2ftlbs I trust it completely.
It is hard to describe how it happened, but I caused it by using a poorly sized spacer that was off center. I also have never fully torqued a cylinder just to check the durations. It is not really necessary for my builds I just got a little silly I think. If I ever try it again I will make a torque plate to distribute the pressure.
|
|
|
|
Post by 90GTVert on Oct 15, 2015 21:01:31 GMT -5
I did that with a brand new 54mm jug once. I welded it back together, trued the sealing surface with sandpaper and glass, and used it for many miles after. It's posted on here somewhere, I just can't find it now. It's been a while. EDIT : It was the Venus' engine. That thing had LOTS of miles on it without any more trouble related to the break/repair. 49ccscoot.proboards.com/post/12848/threadFair warning... I did no research into the best methods. It broke. I had a welder. I figured it was junk if I didn't do something. It worked. |
|
|
|
Post by moofus02 on Oct 15, 2015 22:10:46 GMT -5
Mine broke on the outer edge of the bolt hole. When the guy I got it from pulled the shroud the fin feel out lol. I think it was dropped before it went on and feel apart in use lol. I'm going to use it
|
|
|
|
Post by oldgeek on Oct 16, 2015 15:08:54 GMT -5
I decided to try and braze the cylinder to repair it. So I took an old used 50cc cylinder and broke it like the streetrace cylinder so I could practice technique. It came out pretty good I think, but I dont know how strong it is.  The test cylinder setup and brazed pretty easy. I beveled the top edge of both pieces just a little and held the broken piece in place with a steel tie wrap. The streetrace cylinder was not so easy. I guess I beveled the edges just a bit too much and it was hell to get it set up and stable so I could braze it. I also forgot to take pictures of the beveling before I put flux on it, but here is a picture just before I brazed it.  Work called in the middle of brazing it, so I forgot to take a picture after I brazed it, but I will go back over to the warehouse later and take one. It turned out ok I think, but time will tell if it works. |
|
|
|
Post by oldgeek on Oct 16, 2015 21:15:00 GMT -5
It did not turn out as good as the test piece, but It should work.  |
|
|
|
Post by iwiketuddlz on Oct 16, 2015 22:46:01 GMT -5
Well done good sir well done!! Brazing takes sKill IMO...
You shall be Braaaaping once again s00n!!!
Woooot
|
|
|
|
Post by Lucass2T on Oct 17, 2015 4:58:43 GMT -5
It might come loose from vibrations...but it doesn't have to hold a big load since the whole mating surface bears the load from the torqued head bolts.
I like your solution btw, hope it works out man!
|
|
|
|
Post by Corrosion on Oct 17, 2015 11:14:40 GMT -5
looks good!
|
|
|
|
Post by derbiman on Oct 17, 2015 18:15:21 GMT -5
Fine looking job!!! I used to do a lot of brazing before they brought out the mig welder. I used to braze patch panels at a body shop. The main thing is to keep the metal cool to prevent warpage. Braze a little and cool it with a wet rag then do a little more.
|
|
|
|
Post by oldgeek on Oct 21, 2015 20:17:15 GMT -5
Back to where I started a week ago, checking port durations. I noticed something tonight while looking at the degree wheel. The transfers are 2 degrees different from side to side. So depending which side you are looking at, one stays open for 130 degrees the other 134 degrees. I don't know if it is a common occurrence but it is noticeable to the naked eye on this one if you really look at it.   I am having trouble getting this one set up, exhaust duration is 195 and squish is around .60mm for now. |
|
|
|
Post by oldgeek on Nov 1, 2015 9:34:19 GMT -5
I was planning to finally slap this thing together over the weekend but as I started cleaning and prepping the parts yesterday I realized that the new wrist pin bearing is the wrong size  I may just use the old bearing, but I really hate to. |
|
|
|
Post by oldgeek on Nov 1, 2015 19:51:32 GMT -5
With a little help from my riding buddy we got the 70cc streetrace running again. I took it for a few short runs and it seems to be pretty good. I have some carb tuning to do on the low side, but wot sounds good for the very short runs I did. The OR CVT definitely needs some attention, as I never got it dialed in completely in the first place. I hope it holds together a little longer this time around.
|
|
