fulltilt Posted April 17, 2015 Report Share Posted April 17, 2015 I just got a TY from Canada, about 3,000 feet or 1,000 meters higher than Maine here at sea level. It won't run without the choke at idle. There's green slime in the carb on everything made of brass. I'm wondering if a re-jet is required, I know it needs cleaning at least. Are there recommended jet sizes to start from? Also, someone removed the oil injection, but I see a line to the intake in the front of the carb from the pump, and I was wondering if that should be plugged off. Back in the 80's, I removed the oil injection off a Suzuki TS185, but I drilled holes above the main bearings so fuel mix could get in there and lubricate them. Before I tear this all apart, I was wondering if just removing the pump and lines is good enough. And what oil/fuel would you recommend? I run 80:1 in my Beta, but it's made for that. The pilot jet looks something like "b125" And the main screw cap says "248" stamped on the outside, but I don't see a number on the main jet itself. The slide needle is in the middle hole. Any help would be awesome, thanks. Quote Link to comment Share on other sites More sharing options...
feetupfun Posted April 18, 2015 Report Share Posted April 18, 2015 To start with what carby is on it? There are two different design Yamaha-Mikuni carbies that came on TY175s and they have different jetting. A photo may be helpful with identification Yamaha TYs will work fine just by plugging the oil nozzle and running premix. Completely different concept to the TS185 You will need more oil in the premix than for your Beta because the TY is air-cooled. Once you can say what carby it is, then people can help you with jet sizes Quote Link to comment Share on other sites More sharing options...
fulltilt Posted April 18, 2015 Author Report Share Posted April 18, 2015 To start with what carby is on it? There are two different design Yamaha-Mikuni carbies that came on TY175s and they have different jetting. A photo may be helpful with identification Yamaha TYs will work fine just by plugging the oil nozzle and running premix. Completely different concept to the TS185 You will need more oil in the premix than for your Beta because the TY is air-cooled. Once you can say what carby it is, then people can help you with jet sizes Great, thanks. I know it's a mikuni, I'll get the size and picture. Quote Link to comment Share on other sites More sharing options...
fulltilt Posted April 18, 2015 Author Report Share Posted April 18, 2015 Here's the pic's. The throttle slide is about 23mm OD. After cleaning the carb, it ran much better, but still lean, so I know I have to re-jet. It is actually 4,000 feet higher where this came from. I'll move the needle up one clip until I can get the right jets. The rubber "O-ring"n on the main needle tube and main jet screw look a little rough. Can I get them at any shop that sells mikuni's? Quote Link to comment Share on other sites More sharing options...
feetupfun Posted April 19, 2015 Report Share Posted April 19, 2015 You can get those orings from bearing shops I think that is the 525 model carby. It should be stamped 525 on the side of the body If it is 525 model Yamaha-Mikuni, the standard main jet is 240. I run 220 main at sea level and 200 main at 3000 feet ASL on that carby with a standard TY175 motor, reeds, air filter box and exhaust The standard pilot jet is usually fine at sea level and at 3000 feet, as is the standard needle clip position 1 Quote Link to comment Share on other sites More sharing options...
fulltilt Posted April 23, 2015 Author Report Share Posted April 23, 2015 You can get those orings from bearing shops I think that is the 525 model carby. It should be stamped 525 on the side of the body If it is 525 model Yamaha-Mikuni, the standard main jet is 240. I run 220 main at sea level and 200 main at 3000 feet ASL on that carby with a standard TY175 motor, reeds, air filter box and exhaust The standard pilot jet is usually fine at sea level and at 3000 feet, as is the standard needle clip position What is the standard pilot jet? It has a pilot jet that runs up from the float bowl parallel to the emulsion tube. It runs OK now, but has a really bad flat spot just off idle. And it seems to get worse as the engine gets hot. I tried raising the needle one notch, but didn't notice any difference. Quote Link to comment Share on other sites More sharing options...
feetupfun Posted April 24, 2015 Report Share Posted April 24, 2015 Flat spots like that are usually because the pilot jet is partly or fully blocked. I will look up the standard size pilot when I get home to my workshop. My memory is saying #25 1 Quote Link to comment Share on other sites More sharing options...
feetupfun Posted April 24, 2015 Report Share Posted April 24, 2015 Have just checked the parts book and yes the standard pilot jet is #25 1 Quote Link to comment Share on other sites More sharing options...
shipdamite Posted May 14, 2015 Report Share Posted May 14, 2015 My TY175 didn't have the oil pump and the p/o had not blocked off the intake, although the pump area was properly blanked off. I just used a small section of pipe and a self tapper set in petrol proof sealant. the bike runs on 50:1 Castrol power 1 fully synth 2t oil. the bike is standard apart from boyseen reeds. it ran badly on the standard 25 p.j, slightly better on the 27.5 and now very well on a 30p.j - this also doesn't block up, where as the smaller jets did. otherwise, jetting is as per the book. I used the ty trials carb repair kit that had the o rings and gasket for the float bowl - that made a huge difference, as worn o rings let air bypass, messing up the mixture. I also burnt my whole exhaust out on a bonfire and repacked the end can - that made a really big difference to the running, as did a new airfilter - I use putoline filter oil for that. hope that helps. cheers Andrew 3 Quote Link to comment Share on other sites More sharing options...
fulltilt Posted May 15, 2015 Author Report Share Posted May 15, 2015 My TY175 didn't have the oil pump and the p/o had not blocked off the intake, although the pump area was properly blanked off. I just used a small section of pipe and a self tapper set in petrol proof sealant. the bike runs on 50:1 Castrol power 1 fully synth 2t oil. the bike is standard apart from boyseen reeds. it ran badly on the standard 25 p.j, slightly better on the 27.5 and now very well on a 30p.j - this also doesn't block up, where as the smaller jets did. otherwise, jetting is as per the book. I used the ty trials carb repair kit that had the o rings and gasket for the float bowl - that made a huge difference, as worn o rings let air bypass, messing up the mixture. I also burnt my whole exhaust out on a bonfire and repacked the end can - that made a really big difference to the running, as did a new airfilter - I use putoline filter oil for that. hope that helps. cheers Andrew The previous owner cleaned the exhaust and now it's really loud. I think I need to pack fiberglass in the silencer, but haven't gotten around to it yet. Thanks for the tips, I'll double check the o-rings and jet sizes. Quote Link to comment Share on other sites More sharing options...
fulltilt Posted May 15, 2015 Author Report Share Posted May 15, 2015 Have just checked the parts book and yes the standard pilot jet is #25 Thanks. I'll check it out as soon as my broken ribs stop hurting. Quote Link to comment Share on other sites More sharing options...
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