Like 95% There....

As for the electrical, I kind of knew that I would be handing that over to someone else, as my electrical skills are quite limited. It's actually somewhat of a small miracle that I got the bike to start and even run in the first place. I had a basic understanding about how schematics work, but had to do a fair bit of guessing in some areas. Additionally, the old Yamaha schematics are not 100% accurate anyway!

No matter what I tried, I could not get the turn signals to work properly. And I couldn't even get the brake light to light up at all! Lots of different factors going on here. I'm changing out the incandescent turn signals for LED's as well as the brake light, so I wasn't even sure if they needed to have inline resistors. The brake light claims that no resistor is needed, but I wasn't confident with that. I know that the rear brake switch was brand spankin' new, as I literally pulled it out of an OEM bag to build the brake system. (I bought it 30 years ago and never used it- don't ask me why I even bought it.) Also could it be my bad wiring? So many questions! I just want the stuff to work!

I took the bike back to Alan & Sons. I had talked with Alan at the end of last season and he said that this kind of electrical is something that he can do. I dropped off the bike and gave him the scoop. I even supplied him with another LED brake light, in case the mounted one was actually dead.

About a few days later, he called me and said the bike should be ready for pickup in the next day or two. I drove by at the end of the week to retrieve the bike. The invoice was $409!!! Yikes! No one really likes to do electrical, so if he's going to have to do it, I guess he's going to make it worth his while. He showed me that the rear LED was working- brake light and running light, but only for the rear brake. He believed that the front brake switch was bad, something that was totally possible, since it was the original. The LED signals worked, but didn't blink. He demonstrated that when activating the switch for the left side, it is about 50/50 and suggested that I just give it a good cleaning and that should take care of it. He did have to do a bunch of electrical troubleshooting. He found that some wires were hooked up wrong and that one of the wires going to the rear was broken (no continuity) and needed to be replaced. He also had to solder resistors for the signals. He also connected my little LED's for the license plate, something I didn't even ask him to do.

I found a cheap front brake switch off of eBay- cost me $8. (An NOS one would've cost about $50. I don't think that anyone buying this bike later will even care. I sure don't care.) I finally had some time off from work today to actually test it out and get it mounted. Alan was right about that dead switch! I works now! Now I have front and rear working brake light circuits! That's a really big deal! Now, I can actually ride the bike at night and not worry about someone whacking me!

The next step is to try and get the LED signals to actually blink. I just cleaned out the turn signal switch, as Alan had suggested that I do, since when signaling left, it's kind of iffy. That didn't seem to help. I threw the original flash relay back on, but the left still didn't want to cooperate. The flash relay was crackling and making all sorts of sounds, when I activated the turns. I don't think the switch itself is the problem- it sounds like it's all about the flasher unit. I bought a bunch of flash relays from O'Reilly, mostly electronic ones. I think I just need maybe a 2-prong mechanical one. I'll check that out on Thursday.

Other successes I've had lately with the bike are getting the chamber silencers removed. I had to take them to my favorite local machinist, where he was able to throw some serious heat at them and coerce them to come off. I cleaned up the baffles and got them packed with new fiberglass stuffing. I mounted them back on the bike and did a little alignment on the left pipe. Ready to rumble!

Making Progress!

Well, today felt a bit better. I was still suspicious that the pilot, needle and main jets were all related, so I did some fishing around in the ol' interweb. I bumped into a web page published by Factory Pro, a very reputable shop in San Raphael. They are one of (I believe) two motorcycle tuning shops in the entire Bay Area that tunes by Dyno! I am familiar with them, because I have bought parts from them before for my SV650S. Excellent quality and well thought out and tested stuff.

All the tuning tips pages I have read so far start with tuning from the bottom up- get your idle going, then mid-range and lastly WOT. Their method has you start with the main jets and then you work your way down, since the main jet has an affect on the way all the other ranges operate. This made total sense to me and it is what I had suspected. With their methodology, you do not go to the next step until you complete the current step, since the fatter jets play major parts on tuning the smaller jets. Also this tutorial had a blurb in there about adjusting the float heights, where no one else even breathed a word about that. I changed my floats from 23mm to 24mm, effectively lowering the fuel in the bowls by a smidge.

By the end of the day, I had my bike running well into the red line and pulling pretty substantially! Best of all, not a single plug fouled all day!!

The last range I worked on today was the idle range. I had been running the 30 pilot jets all day, so just for yucks, I swapped out and put in 27.5 pilots. Amazingly, the low range suddenly had a crisp snap and got off the line without dogging! How could this be?? I fiddled with the A/F screw and took my final test ride at 0.75 turns out, basically trying to richen the pilot close to as much as possible. The bike ran well with no real flat spots, and the rpm's would climb steadily. I took her on the freeway for a couple of miles. The bike ran easily at 65-70 mph @5500 rpm. But the engine just wasn't as powerful as I thought it should be. I'll have to work on that- maybe raising the needle one more position or going back to the 30 pilots- we'll have to see.

Anyway, it was a very encouraging day indeed. Tomorrow, I'll be taking Angie into Alan & Sons to have them take a look at my electrical, signals and brake light specifically. Once those are sorted out, I'll feel okay about taking the bike out at night. 

Trying to Keep Sane....

I'm just taking a few minutes to reflect. Building the bike was [somewhat] easy. Sure there were lots of little one-off problems to solve, as is with any "custom" situation. But having to tune carburetors goes to a whole new level!

2-stroke bikes are a completely different animal already, so we're already starting off at a disadvantage- everything has to be just perfect. Then there's the fact that these bikes have been around for so many decades and everyone has them set up differently! Ported cylinders, modified heads and higher compression rates, different air intake systems, expansion chambers, crossover tubes and bottles, reed cages, spacers, etc., not to mention differences in altitude, climate and fuel. So one bike's setup isn't going to be the same as another. And since these bikes are so old, if you've got a more rare pipe, it'll be harder to find someone with another to help you. Yes, there are plenty of forums and QA websites to help, and there are general formulas and methodologies to help get them dialed in, but in the end it's still your headache.

Plus when starting with a freshly built bike and something's not working right, it's not always easy to figure out what is the issue that's hold you back. Since the entire bike is a "system", one area/component can cause another to not function properly. i.e. if your electrical isn't functioning properly you may not get a spark, so the motor won't fire. Or more recently in my case, the head bolts weren't tightened enough, so I was loosing compression hence making it harder to start. So in order to work on one problem, you have to know that the other factors are working.

Last week, I did the famous Dave Feist carb mod (which is a refinement of the Dale Alexander carb mod), which basically reverts the "modern" RD carburetors back to the older R5 carburetors. As I understand it, the R5 carbs were using the primary-type needle jets and had amazing fuel flow. When the RD series came along, the bleed-type needle jets were employed, introducing better gas mileage and emissions. I bought the various Mikuni parts from EconomyCycle.com, as I already had some of the included items in their packaged kit. The conversion simply opens the air jet to 2mm by drilling out the brass ball, then swapping the bleed jet to primary, then swapping out the needle for a more compatible needle. So much fuel is free to flow that smaller main jets are needed that if using bleed-type jets.

I'm still in the process of tuning the carburetors. I just want to be able to pop wheelies like the bike's supposed to, and to know that if I take it out to the track or on a hard ride, the engine will be fine (not seize or foul out). And I know that if I can't figure, I can always bail and hand it over to BRG Racing to stick a sniffer up her ass and Dyno tune her.

Since the Dave F. carb mod, I'm feeling more confident about not hurting the engine (although now I hear ticking noises coming from the top end). I keep a long running Excel spreadsheet with all the different combinations of carb variables i have tried. For a while, the engine would keep dying on me when I take her out for test runs. After the first time, I just bring extra spark plugs with me, since the issue seems to be plug fouling. I'm still learning lots as I go and I'm not always sure what's happening to my engine. But as far as I can logically reason, if the bike dies and new plugs bring her back to life, then the plugs are fouling, which is most likely caused by a fuel mixture that is too rich. As long as the oil injector is working (and is hooked up), then the fuel is getting lubrication and the engine [in theory] shouldn't seize. I'm finally getting out on some longer test rides that demonstrate that the plugs are darker than they should be. I do believe that I have the pilot jets and needle positions figured out, so it's just the main jets now.

I'm constantly feeling that I may just have to resign the bike to a professional tune. But if I have to get the bike up to 500 miles on the new motor first, chances are good that I have effectively figured out the jetting anyway. I'm about half way there now on miles. We'll just have to see...

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.

The 2T Shuffle

It's been a couple of weeks now that I've been fiddling with the jetting off and on. There was a point where I had the low end cracking pretty nicely into the mid-range, but when I tried to hit the open throttle, the bike would just bog, never really getting past 6500 rpm. Making the change to a larger pilot jet really helped the low end, plus I raised the needle just a bit.

In my quest to perhaps still take the bike to someone for tuning, I called and left messages with a couple of parties- Roland Cushway, a well-known internationally famous 2-stroke tuner who worked with Erv Kanemoto, and has won 5 national titles! The other was BRG Racing. I wasn't even sure that it was Roland's phone number, but I left a message anyway. To my surprise later the next evening, I got a call back! He told me a little about his history, but he's very modest about it. He told me that he's more of a machinist. I told him what I've got and he gave me an education in 2T theory! He did have some very good suggestions, some that might be a little over my skill set. The conversation lasted about an hour- I was very surprised that he was that engaged! I really felt honored to have even been able to speak to this man of such greatness!

I also got a call back from BRG Racing. KC called me. He's the owner of the shop. He told me that it would probably be about $400 to do the job, which included about 4.5 hours of labor and dyno runs. They would change the timing, gaps and needles as needed- everything was included in the price. I told him that I would give him a shout in about a month when I've got more miles on the new motor.

Meanwhile I answered a Facebook post to someone who was looking for an RD400 engine case. Turns out that he actually lives in Livermore, so I replied that I've got one. He messaged me and the next day he came by the house. A nice fellow by the name of Julian. I've seen his pictures on the Internet- he's built quite a few bikes and he really knows his way around the Yamaha 2-strokes. I showed him what I've got cooking in my shop. He brought me an assortment of larger Mikuni main jets for me to try out. When he asked me how much I wanted for the case, ti told him that I was going to give it to him- that stopped him dead in his tracks. I really feel like this Yamaha 2-stroke thing is a community. I've met so many helpful people over the decades all having to do with this bike, if he could use the case, he can have it. But I did ask in return that he help me get my bike running and that I may need to borrow some tools. We agreed it was a deal!

A couple of days passed. I tried making some more changes to my carbs, going BIG, but the bike didn't want to start. That's when Julian came over, while my carbs were all over the place. He brought over a couple of timing dial gauges and asked if I wanted to do my timing change to 2mm BTDC now. I said sure!

I showed him a new method that I just pinched off the Internet where you actually use the spark of the spark plug to see when the points were opening. We got the left side set up and found that my original timing wasn't 1.8mm like I thought I had it set- it was more like 1.3mm. That could've definitely had an affect on my top end not going so well. He set it to 2.0mm BTDC. The other side was even worse! It was reading 1.1mm!!! Man, I suck! So he dialed that one in to 2.0mm also.

Then he asked if I want to try and start her up. Oh, shit! I have to assemble the bike under the watchful eye of this 2T stud!? Ooohh, the pressure! Plus I can hardly even breathe with this N95 mask on with all this Covid shit going on! I was sweating and panting! But I did get it back together. And wouldn't you know it? it wouldn't start! I kicked and kicked. We threw a spot of fuel down the right cylinder. Still nothing. Maybe the battery needed more of a charge? Perhaps. He suggested pushing the bike down the street to compression start it, but I said no, because we would just have to push it back. I'll leave it till Sunday. But now I'm just dying to see how the bike pulls with the timing set correctly!!

Cool Your Jets!

Change of plans. I figured if I was going to turn the bike over to the shop in Martinez, they need to have 800-1000 miles on the new engine first, which means that I still need to get the bike started again. I've got plenty of time to work on the jetting, so I decided to get her going this week.

Not so easily done. I tried firing her up and she wasn't having any part of it. I was confident that the starting issue was almost strictly an air/fuel mixture problem, since it was running before. So I systematically started to change the A/F mixture keeping track of exactly what I was doing. I first started incrementally turning the screw out counterclockwise, but was having no success. I would periodically check the plugs and they were pretty dry. I did a spark test on her last night to confirm that the plugs were still firing. Yup. Everything looked good. Well, it can only be a small number of things- spark, fuel, compression or timing. I was sure that the bike was good for compression and timing, and I just checked the spark, so I was on the right track changing the fuel mixture.

Today I started turning the screw back in. Around one full turn out, the bike started acting like it wanted to start. As tired as I was from kicking, I continued my attempts after resting in between tries. After about 3 cycles, the bike started running again, but the idle really needed to be turned up.

I started working from the top of that pdf worksheet on carb tuning, recording meticulously everything I was doing. The bike was running its best around 0.75 turns out. I got the bike to idle at 1800 rpm's. I took it out for a ride working in the 0-1/4 throttle range. Everything seemed pretty good, so I put in a fresh plug and did a plug chop. When I pulled the plug out, it was so white! Not barely even a hint of tan! So this engine is idling super-lean. That's probably why it's having such issues getting started. And the A/F screw is almost turned in all the way, being as rich as it could go, while still having a little adjustment left to it. That was a sure sign that I need larger pilot jets. So I put in an order to EconomyCycle for a could of larger sizes of pilots, and a leaner range of main jets, because I'm pretty sure that I'm running really rich on top.

The jets should arrive in a few days, then I'll be at it again! The jets cost me roughly $50. If I could save that $500 from the shop cost, that would be awesome! I don't need it to run race ready, just good enough to be smooth and enjoy! I'll just take my time and be systematic about the process and I think I can have a good outcome.

SIP Update

Well, I'm pretty bored with this whole Covid Shelter-In-Place thing. I don't have it quite as bad as some others- since I'm a healthcare worker, I need to go out and get to my job. But still, on my days off, I'm here at home trying to keep busy with whatever I can.

Today, I decided to get working again on Angie, my RD400. When I left off at the end of last season, I still needed to get the bike properly jetted. I messed around with a few carb configurations, but it actually resulted in killing the bike altogether. For about a week, I tried to get the motor to fire, but it was a done deal :(

I woke up early. Got some coffee in me and started picking at the bike. I hunted down the original carb configurations for when I had my first successful start and I figured I'd go from there. I swapped out the main jets from 280's back to 260's. I found that I had put in 27.5 pilot jets, so I returned them to 30's. I checked the needle position and the A/F mixture screw. I double-checked my plugs to make sure that I wasn't running 7's. I made sure they were gapped to 0.025-0.028". I wasn't entirely sure if which plug wires went to which plugs, so it was going to be a crapshoot. After a few unsuccessful attempts, the bike finally roared back to life! It ran hella smokey and the idle was high, but at least it was running again!

While I was tooling around the bike today, I also installed the aftermarket horn, although I didn't bother yet to clean and paint the mount.

Last year, when I put her to bed, I was thinking of doing to jetting myself, but now I think I'm over it. There's a shop in Martinez that can tune it in. I spoke with them last year. They had just finished doing an RZ350 and they were comfortable with 2-strokes. I think they quoted me around $500, which is pricey, but I just want it done correctly.

The majority of what still needs to get done is the jetting and the last parts of the electrical that I haven't been able to get working yet- the brake light and the turn signals. I found a small shop in Livermore that said they could hunt down the electrical problems. I'm in the home stretch!