SRX 1108 Race Sled Buildup

Headed out this morning, and I found the issue. It had nothing to do with the timing, but I am pleased to have found the problem. Now I can try taking timing out again. Slowly making progress.... :)
 
I'm not sure if I will be 100% ready, but I will be there. It will probably end up just being a tuning day there, since it is going to be raining here the next 2 days, and I won't be able to get ready.
 
Argh.....having fuel issues and running out of fuel. I have a feeling i was collapsing the pulse line since I was only using fuel line as the pulse line. I found a few specs of dirt in the fuel pump, and noticed that the hole in the needle/seat was smaller than that in the 680 mains I am running, so I enlarged it to accomodate. I'll get this thing figured out eventually. The next set of races are Feb. 16th, and 17th, and I should be ready for them.
 
Well, I was out today. The track is completely screwed up, so I couldn't hold it down for very long. I did make a few 1000-1200' passes, and the motor is working fine again. I ended up spending $50 on braided automotive fuel line, ran an extremely hard pulse line, and re-plumbed my cooling system a bit. It was restrictive. I will head out somewhere tomorrow for some actual 2000' testing.
 
Ok. Today was a much better performance. I finally have the motor figured out, and have solved all of my fuel and temperature issues. I am running it at 14 degrees of timing after 7000 rpm, with VP C-16 fuel, and it is alive. Mind you, it is not completely burning the fuel and my pistons are wet, but it is still running well. I don't have enough compression for 16, but wanted to start safe, and it is.

For the first pass I took it very easy off the line, rolled into it, and pulled 143.1 mph. For the second run I tightened my loose track and put on a new belt and ran 145.4 mph with no traction off the line. I had to get off the throttle 3 times.
For the third run, i put a bit more transfer back into the sled, and it solved my traction issue, but by then the wind had changed to a strong side/head wind, and pulled a 145.5 mph.
The final pass was 146.0 mph. I had good traction, but fought the wind again. RPM is just a hair low. Pistons are still wet. Wash is large. Motor is still running :)

Now I can finally start to do some tuning.
 
I attended the races again today. I only was able to run one good pass due to weather conditions, at 146.3 mph, and found another issue. The new wider 8DN belts are actually riding all the way up in the 8.5" MicroBelmont primary, and are therefore too short to run because it is shifting too far. The belt is tightening up near the 1800' mark. Luckily I did not break any belts, but it is limiting my speed. I am going to start to throw some gear at it becuase I am pulling a rediculous amount of overdrive anyways. I am only geared 23/36 at the moment, and have an unhappy chain angle as it sits with a 68 link chain. I wonder how much overdrive I am actually pulling to run 146. I'm sure it's damn large. It looks like I'm geared for 127.61 mph using this calculator, which equates to 15%.

http://www.snowmobileworld.com/tools/index.php

I'll throw a 24 tooth up top, and see how it pans out for my first gear test.
 
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I agree toydoc, but only to the point where it is shifting out fully in the larger 8.5" primary. The belt is a few mm too short for a full shift out.
 
Well, I went up one tooth on top to 24/36, and pulled a 148.0 mph pass. The rest of the day I spent messing around with fuel with poor results. Then, today, developed a new issue yet again. I have some homework to do now.
 
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