oldbikerehab Posted March 14, 2012 Posted March 14, 2012 Hey classics fans. I'm hoping to get my DT175E restarted and out for a break in ride today and I'm not quite sure on a few things. Here's where I'm currently at: -All new electrics back on the bike and a quick check shows that when I turn the key, my tail light light and rear turn signals work along with the flasher light on the tach, and horn just makes a click when I press the button. I'm guessing that I need to create a better ground for the front flashers as I only grounded them to the handlebars and not the frame like I did on the rear, and the horn is probably dead from rust. -New piston and rings in a freshly honed cylinder. I put a new cylinder base gasket in and coated it with Yamabond 4 semi drying liquid gasket, but have since noticed in the forum that I should have left it dry. Anybody know if this will cause any compression issues or problems? Should I leave all remaining gaskets dry except the magneto? -About to install a new copper head gasket. Regarding the raised ring that just goes around the cylinder opening- Does it need to face up or down? And, is plain old high temp/ high pressure wheel bearing grease ok to coat it with? -Last question, (hopefully), I'm using an aftermarket throttle cable from one of the UK suppliers that is a fair bit shorter than my old one. I tried to connect it last fall and gave up and switched back to my old one without putting much effort into adjustments. Besides the adjuster on the cable, is the adjust plate on the oil pump my only other parameter to work with here? My Clymer manual mentions different adjust shims but I'm hoping I don't have to order more parts. Thanks for any input and wish me luck.
Moderator Cynic Posted March 14, 2012 Moderator Posted March 14, 2012 Hey classics fans. I'm hoping to get my DT175E restarted and out for a break in ride today and I'm not quite sure on a few things. Here's where I'm currently at: -All new electrics back on the bike and a quick check shows that when I turn the key, my tail light light and rear turn signals work along with the flasher light on the tach, and horn just makes a click when I press the button. I'm guessing that I need to create a better ground for the front flashers as I only grounded them to the handlebars and not the frame like I did on the rear, and the horn is probably dead from rust. Yep the lights really need a good earth, the headstock is not a reliable earth path. The horn may come to life with a bit more juice with the motor running, have you earthed it too? mine just croaks too with the motor off. -New piston and rings in a freshly honed cylinder. I put a new cylinder base gasket in and coated it with Yamabond 4 semi drying liquid gasket, but have since noticed in the forum that I should have left it dry. Anybody know if this will cause any compression issues or problems? Should I leave all remaining gaskets dry except the magneto? Smear of grease would have been fine, people get too carried away with all the modern stuff available and forget these bikes are 30 years old. What would you have done in the late 70's, smear of grease. -About to install a new copper head gasket. Regarding the raised ring that just goes around the cylinder opening- Does it need to face up or down? And, is plain old high temp/ high pressure wheel bearing grease ok to coat it with? This time you do leave it dry, as to top or bottom i'm not aware of a right way TBH. -Last question, (hopefully), I'm using an aftermarket throttle cable from one of the UK suppliers that is a fair bit shorter than my old one. I tried to connect it last fall and gave up and switched back to my old one without putting much effort into adjustments. Besides the adjuster on the cable, is the adjust plate on the oil pump my only other parameter to work with here? My Clymer manual mentions different adjust shims but I'm hoping I don't have to order more parts. You probably had the wrong cable, there are many variants and the lengths are pretty important for the correct pump/throttle relationship. As to shimming the oil pump, why? 'If it aint broke' applies perfectly here, just use the cable adjusters. Thanks for any input and wish me luck.
Moderator Airhead Posted March 14, 2012 Moderator Posted March 14, 2012 watch out with pattern cables, i bought one last year (a TSX brand or something like)...and the oil pump pulley cable was far too long so coudnt align the raised 'pip' and the peg ! yes check the distance of the pump stroke and shim it if necessary, the stroke tends to reduce with wear.
oldbikerehab Posted March 14, 2012 Author Posted March 14, 2012 Thanks for the quick replies. I actually have the opposite problem with my aftermarket cable. The oil pump cable is only 11cm, whereas the length on my old cable is 14cm like yours. Looks like I'm delayed again. Time to track down an OEM cable and wait . . . And in other setback news I rebuilt the clutch, got it set and jumped for joy at the smooth action until I realized that the kickstarter needed to go in first. I don't suppose anyone knows a workaround so that I don't have to take the clutch apart again?
Moderator Airhead Posted March 14, 2012 Moderator Posted March 14, 2012 Pretty sure you can get it in there but it's awkward...just working of distant fading memory though
oldbikerehab Posted March 14, 2012 Author Posted March 14, 2012 Great! I'll see what I can maneuver. I possibly have a throttle cable lined up at the salvage yard so I might not be as delayed as I thought. I'll get some pics and maybe a video up when everything comes together.
oldbikerehab Posted March 14, 2012 Author Posted March 14, 2012 Right now I think the only thing I need is a different throttle cable. I got the kickstarter in without removing the clutch and and it turns everything over just fine, but doesn't return to the up position. I think I remember someone else with the same problem on here so I'll have to look for their solution.
Moderator Airhead Posted March 14, 2012 Moderator Posted March 14, 2012 The parts list is a free download? make sure the inboard travel stop is in the right place and fit the spring thus
oldbikerehab Posted March 15, 2012 Author Posted March 15, 2012 Success! I had been using those exploded parts lists and my manual but couldn't make sense of alignment for the spring but your pic helped put it together. Kickstarter is working again, without removing the clutch! They were able to modify my old broken cable at the shop so I can use that until I order a new one. I guess the aftermarket that I bought is a bust. Countdown to startup is taking longer than planned, but I'm back on track . . .
Moderator Airhead Posted March 15, 2012 Moderator Posted March 15, 2012 you will no doubt find that the OEM cable is sold in seperate pieces (see the parts list)
oldbikerehab Posted March 16, 2012 Author Posted March 16, 2012 you will no doubt find that the OEM cable is sold in seperate pieces (see the parts list) Two unfortunately pricey parts. I'll have to make do with my repaired cable for a while longer. The bike is just about together. I guess I'm going to go with the ridge on the top end gasket facing up. It just seems to look right that way. I'm also going to tighten it down dry per Cynic and a few of the local wrenches I've talked to, though I'm curious why they Clymer manual says to smear it with grease. Are there any performance related issues? I can't find an answer. The gap between my front wheel and spoke seems pretty tight to me. It's just shy of 1mm. The front axle is torqued to spec, the boss is in the groove and the wheel turns fine. I'm not sure if I should take it off and try to re-mount. The electrics are all working right now with a better ground and I'm getting a really nice blue spark at the plug, though I'll have to wait for startup to check the headlamp which is a German 6V halogen in a Husqvarna lens. I guess all the electrics are aftermarket. I've got a decent coat of Pennzoil 2 stroke in the cylinder and wiped the reeds and inside of the carb with Seafoam. I've heard mixed opinions about gas after a rebuild. I've heard some say, to just add a tablespoon of 2 stroke oil to the tank, others to go straight gas and just put a teaspoon of 2 stroke oil in the cylinder, some say to add a bit of Seafoam to the tank and keep the cylinder coated just so it doesn't puddle at TDC. I'm leaning towards the latter Any thoughts? Getting closer . . .
Moderator Cynic Posted March 16, 2012 Moderator Posted March 16, 2012 Re the oil question. There are a lot of miss informed myths floating around about that. My take is the oil i used on assembaly will be enough for the initial start up then the pump will take over. Its far better at adding the right amount of oil and is THE best invention Yamaha dreamed up. Adding 2 stroke to the tank is less than ideal as once the autolube is checked and bled you will be running oil rich, which by obvious deduction means fuel weak, bad news for any 2 stroke. Oil down the bore.. First class way to foul the plug if you ask me. You have me on the Seafoam? Good luck with the first run.......
oldbikerehab Posted March 16, 2012 Author Posted March 16, 2012 Thanks! I couldn't agree more on the autolube pump. It blows my mind when I see commenters in forums say that they want to disconnect it. Seafoam is motor treatment that is supposed to be good for storing engines and bringing them back from storage/rebuild. Since the only thing that didn't get taken apart on this project is the bottom end, (flywheel was solid, if it ain't broke, don't fix it type thing), I've had a few people suggest it might be a good idea to help loosen up any junk in the crank case. Now that I think about it, I think I'm just going to probably go with gas and oil and let this machine do its thing. http://www.seafoamsales.com/gasoline-engine-faqs.html
Moderator Cynic Posted March 16, 2012 Moderator Posted March 16, 2012 Thanks! I couldn't agree more on the autolube pump. It blows my mind when I see commenters in forums say that they want to disconnect it. I think its because the racers didn't use them they thought it was better to add your own 'blend'. The fact they left the pump in place so it would still drag on the crank nullifying any benefit was lost on them. Or the busted pump seemes too expensive to repair. They are cheap compared to a set of pistons. Either way i think there daft.
flyday58 Posted March 16, 2012 Posted March 16, 2012 Just crossed 100 miles on my rebuild, new 66.5mm piston, rings, fresh bore. Put a little grease on the head gasket per Clymers with no ill effects (so Far). Also placed the gasket ridge-up, as it just seemed right. Put a light coat of oil on the cylinder walls and put it all together. The first 20 to 30 miles had a fair amount of blue smoke above 3000 revs (not going over 4000 revs for the first 50 miles) but that gradually cleared as the rings seated. After 50 miles I did short bursts to 5000 rpm before settling back to 4000 or less, and today I took it to 7000 for the first time. All good so far... I after 50 miles I purchased a 45-tooth rear sprocket to get the top speed up. Here in the good ole Estados unUnidos alot of us live in rural areas, with four-lane and divided highways/ motorways prolific. At 40 mph with the 49-tooth standard sprocket I was only doing about 35 or 36 mph at 4000 revs, way too slow with a jacked-up Ford Super Duty riding your taillight. Or a Prius driven by an over-anxious cellphone-weilding teen, for that matter. I now get 41 mph at 4000 rpm, so I'm pleased with the arrangement. The clearance issue on the front forks: mine is nearly identical, maybe a tad wider around 2mm. Hasn't been an issue riding. I did have a problem on initial start-up. This was 5 or 6 years ago, and the bike ended up sitting in my shed in a forgotten corner until the petrol in the carb turned to a lovely varnish. The problem was the engine would not rev over 3000 rpm, no matter what I did. When it got to 3000 it just sounded like it was firing once a second or so, just kind of a pop-pop-pop. I rode it around the yard but of course, not very quickly. Tried all kinds of adjustments, ohmed everything I could think of. Finally threw it in the shed and forgot about it. When I decided to re-resurrect the project this December, I did a lot more research but didn't discover this forum till February, so didn't have much good intel. I decided compression was keeping the thing from revving, as I could pit a stick of gum between the cylinder and the piston. Needless to say I was a trifle upset when the machine still refused to rev! THEN I discovered this site and was steered to the source coils. Mine were pretty smarmy-looking, the pulser wire had a bare spot near where the flywheel turned, causing a possible short, and source coil #1 was giving me strange readings on the meter. So I purchased a stator that looked in good shape from that place we all get this stuff, and EUREKA! Revs all the way up now. I just wish I had documented everything I did, and that my last computer hadn't died and taken the early pics with it. I am currently shopping for a DT 360 or RT-1 to restore and will definitely document document document. Can't wait to see your beast run...
oldbikerehab Posted March 17, 2012 Author Posted March 17, 2012 Thanks for the info flyday! I'm sure I'll fog the neighborhood as well if she starts up and all goes well. Everything is back together, torqued to spec and fluids filled. The only thing I'm thinking about changing out is the oil line coming out of the oil tank since it's a little bigger diameter than my old one and I'm not sure if it will have an effect on the pressure in the oil pump. It's dark now so I'm going to wait until morning to give it a once over safety check in the daylight before turning the key. Otherwise, I gave a few kicks without the ignition on and the compression sounds solid and I have a feeling it should be a quick start. I hope . Regarding your sprocket swap: Mine came with an 18 tooth sprocket on the front and the 49 on the rear. When I was riding before the rebuild I never went over 55mph because the bike was a little creaky and I didn't want to push it, but I don't remember my rpms climbing very high at all. I'll definitely post my results after the break in period.
Moderator Airhead Posted March 17, 2012 Moderator Posted March 17, 2012 I think theres something reassuring about seeing the oil in the line so I use clear tube, its cheap too http://www.ebay.co.uk/itm/YAMAHA-DT175-DT175MX-DT-MX-2-STROKE-OIL-LINE-KIT-/270830601613
Moderator Cynic Posted March 17, 2012 Moderator Posted March 17, 2012 I think theres something reassuring about seeing the oil in the line so I use clear tube, its cheap too http://www.ebay.co.uk/itm/YAMAHA-DT175-DT175MX-DT-MX-2-STROKE-OIL-LINE-KIT-/270830601613 Saved me when i picked up the wrong oil. Same make, same colour bottle but a snazzy new lable. Next day the bike is running hot, and its immediately obvious the new stuff won't pump. There are big gaps in the contents of the pipe, thankfully i hadn't gone very far. On investigation in the smaller print on the back of the bottle of said universal 2 stroke was little print giving the premix ratio. Doh. The TDR and the DT get the same stuff now bought a gallon (£20 odd for semi synth sports stuff) at a time from a motorcycle service/sales place along the A5 from me.
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