flyday58

Thanks for the link. And thanks for clearing up who Flybe is, always wonder about the labels on the side of airliners over yonder!

So everything is on site and ready to be installed, now I just have to find time to get to it. Hopefully Friday or Saturday I can post a ride report. I had trouble finding someone to set the rivets in the clutch basket for me - Here in the US we are fond of giving up the fine arts of keeping the old stuff running in favour of football (not futbol) and following Trump tweets and the latest mass shooting. Damn, I wish the forum name "Cynic" was still available, cos it's ME!! Regardless of all that, I found an oldster locally who has, for me, a dream shop of old motorcycles and parts. He has a stack of Yokohama tyres for Enduros that he "may" part with some day; He has a Yammy 175 with a head that could be from a WWII Corsair or Hellcat, pre-reeds cylinder, an expansion chamber pipe I don't recognize, and a weird front fork arrangement. I was in Heaven! He didn't even charge me to drive the rivets on the basket as he had never seen one apart before and appreciated the experience! So keep tuned, we should be riding again shortly...

Update: almost there. I replaced the bearings and seals in the rear wheel so it's ready to go. I received the correct internals for the clutch basket, now it's just a matter of getting the rivets bucked and I can install it and put the engine back in the frame. I am anxious now to see how it's going to run and ride. Alas, it will be next week before I can get the basket to a local recommended machine shop to get the rivets set. Stay tuned.

Plus it's brand new!!

I swear it wasn't me!! Never had a good look at it though. Guess I should look at the front wheel... Some ancient history: I went to what we call in the states a junkyard, specifically a motorcycle yard, back around 1997 or 98, as near as I can figure, in search of a project bike. I had been out of touch with scoots for quite a few years, but something gave me the bug and I went looking. I found two 1978 DT175 basket cases in this yard and picked them both up for $125 US. It took quite a few years to get it sorted to one rideable bike, with copious support from a then-budding ebay. About the only thing original from that rust-infested junkyard is the frame and engine. I'm pretty sure the wheels both came from ebay, and they just got bolted on. I think. Lots of water under the bridge of my memory, and I can't find the pics I'm sure I took as I went along. Pre-digital camera days, so not on my computer. So waiting on parts, the true sign of an avid Yamaboy. At least I have the TW200 to ride whilst I wait. It's a fun little thing, for something with valves, that is. I have 32 miles on it so far; I've been sorting the jetting on it with the help of peeps on its eponymous forum.

Um. Update from Mr. Stoopid. Firstly, thanks to all on this site for your valuable {can'tthinkoftheword} through the years. It's great to have a forum with such knowledgeable and nice chaps/chapettes to come to. Unlike many US-based forums. Insight! that's the word!! Your valuable insight! And if I had come back to this thread I would have purchased the correct clutch hub cushions the first time; all I had to do was watch the vid Sir Hat of Black posted. Now I am waiting for the second set to get here from Thailand. Engine is together and ready to install, sans clutch basket, which is awaiting said cushions. So I was installing an NOS brake lever on the rear wheel to pass the time, and noticed a teeny bit of wobble with everything still tight. Teeny, like a quarter-inch of front-to-back play on the left bearing side. So Señor Dumbass removed the axle, and there's no way anyone on this forum is savvy enough to guess what I found. Just NOOOO way. What? Did you all say a shot bearing?? Really? Everyone knew to check this but me??? I'm fairly certain where my vibes have been coming from now. I should know better. Additionally I discovered the internal spacer is missing from inside between the bearings. WTH? I know I didn't leave it out, and I've had the bike at least 20 years now. Curiouser and not so much. So the saga continues this side of the Big Water. "Richard, use The Force! Don't give in to hate, that way lies Harleys..."

I DO know about rotating those darn plates! Interestingly, the left-hand case I didn't reuse has the original bearing still in place and it has a good bit of wobble with the crank installed also. Right side seems okay, must be a leftie thing!

Depending on where the bike has been stored I would do a thorough check of all the wiring. Oops, just noticed the post date. Still there?

Thanks for the link. I will try to get the basket apart tomorrow and see what it looks like in there. I was discouraged with some crank play I found so I decided to tear the motor apart. Good thing, it looks like whatever case sealant I used 10 years ago failed; it appears that the 2-stroke oil was leaking into the crankcase, causing the foul odor and cruddy-looking case oil. The left main bearing has a ton (tonne) of movement up and down so I'm going to replace it. I've forgotten the history on this motor but I think I swapped the left crankcase out without bothering to renew the bearing. I'm hoping a new one will take care of the vibes issue; if not I will see if I can renew the bushes in the clutch basket. '78 and up clutches are scarce to non-existent right now, although I did locate one on UKbay. Also CMSNL claim to have a new unit in stock, but I cannot justify the price just now. So renewal parts are on the way, I've got a tube of Yamabond standing by, once more into the breech, as Ghandi used to say...

Wow, thanks for the vid. Is it possible then to source the cushions and rivets? I will check around, maybe the NL parts site will have them...

So still trying to get this sorted. I've spent so much time trying to figure out the overheating issue that I set aside the vibration problem till that was solved. Now it's sorted I am back on the vibe deal. When I rebulit the 2A7 years ago I put all new bearings in. Except for the clutch basket 'spacer'. I remembered this recently so I am channeling my energies in that direction. So the vibe comes in all gears at somewhere between 3500-4500 rpm, and again up around 6000. Knowing I replaced all bearings except anything dealing with the clutch I decided to start pulling the clutch side apart. There is a rancid smell coming from the clutch parts and maybe elsewhere, an odor similar to a fridge that has been "accidentally" shut off by a neighbor whilst we were on vacation...don't ask. The oil is fresh, only about 50 miles and 8 month's worth. The bike is an indoor girl when not being ridden. The question is this: the clutch basket is a two-piece affair, held together by rivets; is there supposed to be any free play between the outer driven gear and the inner basket? I have about 5 or 6 mm rotational play between the two components. I do not feel any shock-absorbing material in the basket so I am thinking there should not be any play. If this is so I would think that would account for my vibration issue. I don't have an extra basket to check against so I am calling on you subject-matter experts for advice. Hoping all is well across the Atlantic. We have Trump. Richard

Yes, I believe I was. Glad to finally get it sorted. I'll turn 60 in April so good to be alive into the bargain.

Evening all, thought I'd check in. I have some good news, well, at least for me. I finally have resolved my overheating issues with the 78 DT175. Turns out the little Yam actually needs the oil that gets injected or premixed, as each of us prefers. We all thought it was seizing due to running too lean, and while that may have been partly true, I discovered an error on my part that could have done serious damage other than heat seizure. It finally occurred to me that the large air gap in the clear plastic Yamalube tube was, in fact, preventing proper delivery of said oil. I thought that normal running would remove the air gap. Alas, 'twas not so. Things were made a little more problematic because this year model injection pump lacks the thumb primer wheel. SO I never bothered to try to clear the air gap. I hear y'all laughing, don't blame you. I finally saw the light and wised up, eliminating the air gap by removing the cylinder end of the tube and letting the engine run until the oil reached the full length and dripped out, shutting off and reattaching the tube. No more air gap. No more seizure. Next: getting the jets dialed in for my 4000m mountain heights. Thing just sputters and pops and will not go above 5000 rpm at WOT, only bogs down. I had a 150 main jet in there, and once again, light bulb. I had cleaned up the tap again, and knew it was functioning because I have a small in-line filter installed, and when I close the tap I can see the gas drain out. AHA, methinks. I'll let it run the carby dry; if I can get full revs as the petrol goes, then I'll know the solution. I'm sure everyone can guess what happened - motor revved to 8000 before the supply ran out. I was pretty much elated. I ordered a range of leaner jets. I am currently running a 120 main and a 20 pilot jet. I forgot much fun this little Yam can be, it's got its soul back. I'm having a blast zipping up and down the mountain. Some next steps will be to exchange the OEM-profile rubber (Shinkos) for a more agressive tread for rocky mountain riding (suggestions welcome). A gel battery will be ordered as soon as I post this. I need a touch more oil in the forks, I think. Coming over a berm I can feel them top out to full extension. AND I need to address the petrol tank issues, what with no ethanol-free strains available here the rust is hard to keep at bay. I guess I'll Creem it but suggestions, again, are welcome. So that's the latest in the Blue Smoke Saga from the the land of Trumponomics. I hope you are all well these days. Get out and ride, I am. More to come. Richard

So there's also the 71 AT-1 and the 74 GT80 to talk of. I've been working with the jetting on both bikes, leaning them out for the high altitude here ( around 4000m). I think the AT-1 is close but I'm waiting on a new air filter before going further. It seems as if the 125 is not getting enough air, and the filter, while clean, looks almost original. So waiting on a filter. I went from a 150 to a 120 main and a 20 pilot jet on this (same jets as now in the DT). Runs better but bogs quickly going uphill, and the airbox sounds almost like a resonator, like it is laboring very hard to pull air through. I don't want to run it without the filter due to dusty conditions here, so we wait. The outfit I ordered from on ebay somehow overlooked my order; when I asked they were upset to learn they had missed it, sent me the filer AND gave me a refund. Score one for the home team! The GT80 improved quite a bit with just the main jet swap; pjmotorsports.com did not have the proper pilot jet for the little Yam that could. Went from 94 to 85, then 80. Very peppy now but I think even my slight 11 and a half stone is a bit much for it. I talked my dearest friend out of it and he was the original owner, so it stays unless he ever wants it back. As soon as I get the AT-1 sorted it goes on the auction block. I always lusted after the thing from the time the first one showed up in my neighborhood in the early 70s in its glossy candy red livery. I came across this one in Denver three years ago and jumped at the chance to own one. But I don't have the stamina to look after this many bikes and do them all justice anymore. plus I'm sorta looking at getting a brand new TW200 so need to make room and got to keep the 80 and the 175 and the 1200 something has to go wifey is threatening bodily harm. What? I didn't say nothin.... Now we are caught up. Richard

Bought my 78 carcass in a local junkyard and rebuilt it from ebay and a few online houses for the bits like screws, packings, gaskets, and bearings. I recently moved and got rid of all my extra 175 parts except a seat and a couple of petrol tanks. Sorry! I've used Yambits, Partzilla, Bike Bandit and CMSNL for most of the small bits.

Thought I still had some DT stuff but all that's left is a couple of gas tanks, a fender and a bottom end. Except for the whole bike, that is.

Um...dang, I actually helped for once. At least you know what you got now. Not why but hey, it's a start!

There may be a number on the harness which identifies it, near the steering head I think. If you find one it would tell you if the harness is the correct one or something a po fitted for whatever reason.

Many thanks, Mr. C!

Wowzer, great info. Does most of this apply to the non-motos? I never knew the caps were resistor types, something I must look at on the 175E. Surely there is an alien civilisation four or five light-years away marvelling at the brilliant minds on this site and wondering how best to get in touch. Y'all smart!

Decided to give the old mill an extreme makeover. Started the teardown and will post the pics when I return home from snowy NYC in a few days. So far all looks okay. The armature popped right off the left side of the crank, so that concern is past. There IS pretty good vertical play on that side so new main bearings are in the offing. The piston head is well carboned, and there is definite wear and some blow-by at two of the intake ports on opposite sides of the cylinder. Sadly on this side of the Big Water it is getting harder to find shops or garages to do the sort of work I may need, like cylinder boring. Don't EVEN get me started on rechroming! However, I am sure I will overcome! Again, pics to follow...

What I really should do is take the young lady down to airier climes and see how she runs with atmospherics she can sink her teeth into. The PO was riding it in the mountains of Colorado but he was. You know. Old. May not have noticed it running poorly. My truck currently resides under almost a metre of the white frozen stuff so will have to dig it out first, then unload said stuff from the bed before I can load up the AT1. Unfortunately my back is on vacation somewhere and hasn't told me when it's planning on returning so it may be a while before anything gets done round here. Getting old ain't for wimps, apparently...

Okay, bizarre behavior on the site with pics since I last visited, but got it done. Was finally able to get a good view down the bore at about the 5 o'clock position and it does look like a blind hole on this model Mikuni. I have a spare and they are the same. Replaced the 140 main jet with a 150 and dropped the needle one notch leaner, plus emptied the old gas and put in fresh. No extra pilot jet so it is still stock. Seems a little better but it may just be our old nemesis, age. I think I will remove the motor and start a core rebuild with all new crankcase seals and bearings, maybe go to oversize on the piston. Biggest issue I will have is I now live in an area with even fewer prospects for bore jobs and the like. Only 3100 miles on it, so maybe just new rings. I will document the teardown if I decide to go that route and post to the forum, so look for that. Richard

I'll pull the carb back off and take some pics. As for the plug, it is darkish tan and dry. And this is on the AT1/ 125. And to be clear, I have yet to malarkey with the jets! I'll pull the carb back off and take some pics. As for the plug, it is darkish tan and dry. And this is on the AT1/ 125. And to be clear, I have yet to malarkey with the jets!