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I really need to get more sleep. Good news is that the intake air temp sensor is mounted and wired in, along with the coils. I'll be able to figure out the gas tank fitting and rewiring the points in the next few days. Thanks, Joe
Update: I've got the head temp sensor wired in, along with its mounting point on the head. I've only got to wire in the o2 sensor, fuel injectors and tps sensor and I'll be able to start cleaning up the wiring.
I also machined the head to fit my bore size. The squish band is 50% of the bore area and at a 17 degree angle. the second angle is at 46 degrees going all the way up to the plug hole. This gives me 19.5 cc's. The stock heads were at 21.5cc's and the kawi heads were 16.5cc's stock. This should bump my corrected compression from 5.9 to 6.4:1. I've still got to feather in the bit by the plug and chamfer the edges.
I got the manifold adapters bored out and finished. The throttle bodies now have a functioning idle adjustment and the throttle cable works.
I plan on finishing up the heads and mounting the o2 sensor tomorrow. After that I'll only have the few things more to wire up and I can start messing around with the computer. thanks, Joe
Although I've got no pics of the bike for this update, its still pretty significant. I finished the wiring and double checked all the connections. I decided to switch to tunerstudio instead of megatune based on the reading I've found. After installing the drivers for the serial port to usb adapter, I switched on the key and was able to connect the microsquirt to the computer. I've already calibrated the tps and temp sensors. Honestly, I spent about 5 minutes just moving the throttle to see the needle move around the gauge.
I've got the gas tank modified for a simple 5/16 hose fitting and I've also decided to repaint the tank correctly. The first time I did a little bondo work and it was ok, but I now have much more experience with bodywork and have really made the tank look great. I also filled in the badge clips on the tank as well. Both the tank and the sidecovers are going to have no badges on them, you'll have to guess at what the bike is. The final color will be an urban grey metallic. Heres what it looks like on a subaru:
I've also gone as far as redesigning the seat as well. I went the easy way out the first time by using the back of a gas tank for the bumstop and the cutup seat pan. Again, it doesn't look horrible but I want to make it look good. The new one will be about 2 inches skinnier at the widest while still keeping the same width in the back and front. The original is very wide and can be uncomfortable on the inside of my legs when riding, while this new design should be much better. I'll be using 1/8" aluminum for the main seatpan and a fiberglass bumstop. Maybe I'll loose a few pounds here, because my first one is quite heavy. Plan on an update Tuesday or Wednesday when I'll be painting the tank and by the end of the week I'll be able to kick it over. Thanks, Joe
Good color pick, that'll look great! I'm so pumped about the fuel injection, you're doing some great work here, man! I haven't done too much reading about either, but I'm curious, What kind of advantages have you found/read about in regards to going Tunerstudio instead of Megasquirt?
Hey about your old seat... Your bike is (currently) the same color as my T250 And I'm looking for a seat. Maybe we could work something out? Feel free to shoot me a PM, I'm in Michigan (right outside Ann Arbor) so you wouldn't have to worry about shipping it... That and I'd love to see your bike in person!
Good progress Joe. Unfortunately we need to go with the rather larger MS3X for sequential injection on a triple - now that it's available. Just need to work out where teh second injector goes. Shower types are good with vertical intakes , but not so suitable for horizontal types. Maybe I'll have to put them straight into the reed boxes.
It's been a while, but I'm very close now to starting it up. I had some trouble with getting an ignition input. I had to use the vrin input instead of the optin. After I got spark to both sides, I couldn't get the timing light triggered. Turns out that the coils are getting the needed power, but the spark plugs were still gaped at the original .020". I used a universal plug tool to expand the gap to 3/8" and I got the trigger working. Now both sides are timed correctly. I also wanted to see what the power of the coils was. I kept opening the gap until I got to 3/4". It was sparking consistently at that length. So power wise these should be more than enough.
I also noticed that the fuel pump wasn't kicking on for the initial prime. I assumed the computer would trigger the relay on the switched power pin. Turns out it is actually the ground for the relay. After some soldering and connectors, that is working well. I need to pressure test the fuel rail before starting, but I don't have too many doubts. The tank will be painted on friday, so hopefully I can get it going this weekend. Thanks, Joe
I've got the tank painted, and the aluminum for the seat. The paint turned out perfect. I'm very impressed and it will look great with the rest of the work I've done on the bike. I think I can put a couple hours into the bike tomorrow and pressure test the fuel system with a little mockup gas tank and possibly start it.
Here it is in primer. As you can see, I skinned over the badges on the side. I final sanded it with 400 grit.
This is it with the final coat. The metallic looks stunning under florescent lights, I cannot imagine how it will be tomorrow when I can get it in the sun.
On the last pic, the dark ridge at the top is the shadow from the fork on the lift truck. Pretty good for spray paint. Its a single stage acrylic enamel that was custom mixed at my local paint supplies place for $18 a can. It stands up to abuse and gas pretty well.
Re: '75 suzuki gt250...Running with fuel injection
Pretty big update. It took a while, but I finally worked all the bugs out. I ended up going with the original coils, so the microsquirt will be fuel only. I had some difficulty with getting a clean signal from the triggering wire for the coils. It seems to be a common practice to set it up like the diagram below:
This gave me a pretty good signal on tunerstudio. One thing I ran into was the rpm would register, but the injectors wouldn't fire. This was due to some firmware corruption and after erasing and reinstalling the firmware, I was able to get the injectors to fire. Heres the video of it running:
http://youtu.be/_aAfptmI4jU
I did get it running earlier for a few minutes, but the rpm started spiking to 50,000 and caused the bike to run poorly. After checking the tach input from the coils, it read 12volts and dropped to 1.1 volts when triggered. It has been like this since I first tested it, but I knew in the back of my mind that it should drop to zero volts, not 1 volt. It then hit me. Why trigger off the coil when I can run another wire from one of the points itself? I've now got one wire from the points, and one wire from 12+ with a 1k resistor that is then y'd to the input on the microsquirt. This gives me a solid 12volt to 0 volt signal that only passes a very small current through the points. This doesn't affect the function of the spark or the points itself. It now has a consistant signal on tunerstudio. Now the next step is welding in the o2 sensor bung and fabricating the new seat. The future seems bright! Thanks, Joe
I'm using the points as the signal for now. After I get things going smoothly I'll make up a toothed plate and replace the points with an actual hall effect sensor. The nice thing with the points though is that they are quite reliable and very cheap to replace and fix if necessary. I was able to weld up the o2 sensor bung and took the bike for a spin. It idles around 14-15, but jumps to over 18 when I put a load on the engine. I have a very good feeling that its something to do with fuel pressure. I'll put a pressure gauge inline and see what its at. Thanks, Joe
Do you have the fast idle solenoids connected? Sounds like that system adding more air.
Toothed wheel is even more reliable than points and less "misfires/false positives" caused by arcing or points bounce. Ignitech have sensors and toothed wheels really cheap, but then you also have to have an ignition system to drive the coils.
I tested the fuel pressure and it's consistent at 50psi. There are no arrangements for idle solenoids on the bike right now. What I believe is going on has to do with the acceleration enrichment. I haven't touched the settings at all, and they are way off. I dropped the low rpm limit from 2500 to 1500(a little above idle). I also think the accel enrichment never kicked in because the tpsdot threshold was at 200%. What I have done is lowered that down to 50% which should be about average. I've also ran the bike at idle and was able to verify on the accel table that it is kicking in above the rpm I specified. I was messing around with the old seat and ended up cutting it into pieces to get a good idea where I want to go with the new one. I should be able to test the new settings in a few days.
What I have been up to is a new aluminum seat. I picked up a harbor freight 30" slip-roll/brake/shear. It handles the 1/16 aluminum pretty well for the slip-roll and for small pieces(12") for shearing and bending. The seat is made of 1/8" aluminum with a 1/16" top. It's pretty light and should be more than strong enough for what I'm using it for. I still need to make up some brackets for the rear and box in the back to hold the tail light. I'll be going down to just one flush mount light for this seat. I chopped off the original front seat bracket and machined a new aluminum block to bolt the front down at the correct height. I have lots of grinding on the welds before paint, but at least I can work with something. The last pic shows an exaggerated view of what it should look like when complete. Thanks, Joe
I think this is the most interesting thread I have read on here. Kept my attention to the end and I didn't even skip any pages! You have done a amazing job, looks and sounds amazing, congrats!
More work done on the seat. I just need to make rear mounting tabs and smooth out the welds. I've purchased some new tail lights: http://www.ebay.com/itm/170814735382?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_1303wt_1270
I think I'm going to have two aluminum strips on the top of the seat that will look like fins. they'll have a small taper going back to the end of the seat having the lights flush with the end. Its hard to explain, so I'll post some pics later this week when I get them machined out of aluminum. Heres how the bike looks so far. I did notice the rear of the seat has to come down a bit to be parallel with the frame. I'll keep that in mind when making the tabs. I did weigh the seat. The original modified one was about 8 lbs, the aluminum one is just over 4 lbs. Thanks, Joe
joeschuit, Awesome stuff man. I've been watching this thread for a while now with anticipation, only registered to comment now. I've been browsing the suzuki2strokes.com forums mostly, but then came upon your bike. Great work, really awesome as I am looking forward to doing EFI on a t350; Your thread here has saved me countless hours.
The thing that made me comment now is, and please don't take offense, I think you should consider matching the corners of your tail section to the radius' of the tank corners. Doing this will go a long ways in connecting the visual form language to the rest of the bike.
This is the tail section I am working on right now for my t350
Again, thanks for your contribution here, this has given me much more confidence about going to EFI.
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