I Hate to Admit It....But I Might Have Overlooked Something...

I went back to a more conservative jetting setting and within 5-6 kicks. I took a short video for Julian to show him that the bike was actually running and to demonstrate the popping that I told him the bike was experiencing. When I reviewed the clip, I noticed that some of the popping was coming from the head gasket, that puffs of smoke were coming out when it popped! I suspected that maybe the head bolts needed a little tightening. Indeed they did!

I checked the bolts and some were so loose that I could unscrew them by my finger strength! I guess it's my fault that I didn't think of this earlier, since the motor was freshly built. But I would have thought that Paul should have told me that after heat cycling the motor a number of times, I should tighten up the head bolts!! Details, Paul!

I tightened the bolts to 17 ft/lbs. in a criss-cross pattern across the entire head, since it's a one-piece head. Amazingly afterwards, the bike started on 2 kicks! And that's when the engine was dead cold from a sit overnight!! I heat cycled and cooled the engine 4 or 5 times and retorqued the bolts over and over again. Funny thing- the popping went away!! as well as the puffs of smoke!

So the loose head could explain a bunch of things going wrong. First of all, the engine wasn't getting good compression, which would make it hard to start the bike. Also it made it harder to reach the top end, running out of power. Secondly, the fuel ratio in the combustion chamber was more lean, because every time the piston moved downward to do a filling cycle, it would be pulling in additional air through the head gasket leak! So suddenly my A/F mixture was all off and all the testing I did has to be done all over again!

After a little testing, I calculated that I would be able to move down to a smaller pilot again. So I popped in the 30 pilots and I put in smaller mains, moving to 250's. I took the bike out on a run and it ran nicely on the low end. (I still have to work on the mid-range.) I took her down Isabel and yanked on the throttle WOT. The bike actually pulled up to 8500 rpm, that's the redline!! It probably could have gone into the red, but I didn't want to hurt the motor just yet. Just after that, the bike died, running on one cylinder. At first I thought that maybe I seized the engine, but after testing I believe that I just fouled one of the plugs. I looked at both the plugs and they were a pretty nice tan. I think maybe one of those old spark plugs just gave out. I'll pop some newer ones in and do more testing tomorrow.

Engine Cosmetics Just About Done!

I'm meeting up with my engine builder on Sunday to drop off all the parts. It's my last push to paint, polish and shine all the exterior engine parts, before handing everything over.

For the past 3 months, I've been trying to buy everything needed to get this motor done right. I've bought almost all Yamaha OEM engine parts, with the exception of the connecting rods, some gaskets and miscellaneous parts that were sourced by Yamaha at the time i.e. Sudco seals, etc.

Here's some before and after pictures of the head.

The first thing I did was strip down and polish the Daytona head. I actually started the stripping process 10 years ago, but then just stopped. I've had to buy a used right side engine cover, since one of the allen bolt tabs was broken off. I probably bought the bike like that. All the covers were cleaned, degreased, paint stripped, then painted with PJ1 satin black. I media blasted both cylinders and the inside fins of the head with walnut shell, then painted those with PJ1 high temp flat black paint. Afterwards I took a Dremel flap wheel to the edges. Everything came out fantastic!

Originally I thought I was going to media blast the engine case too, but in the end, I just took some aluminum polish to it and polished it up by hand. I bought some stainless steel allen bolts for the covers on eBay. The finished product should look fabulous!

The build process should take about 3-4 weeks, depending on what Paul has got going on in his private life and how many parts might need to be ordered. I'm pretty confident that he will have all he needs to get complete the job. After the initial build, I'll install the motor, finish the build, and hopefully the bike will start up. I may just bring the bike back to Paul on a trailer, before the inaugural start up, just in case I missed something critical in the build process.

Here's a quick mock-up of the motor- just a glimpse of the what the motor might look like when it's done.