Cynic

1/4 inch installed is a bit much. The black under the piston if its excessive generally indicates that the piston crown is getting too hot, could be lean mixture, ignition out by a few degrees (one of the few things these engines are sensitive to). Knackerd rings won't help as you will as a result be running weaker as the compression getting past the rings reduces the draw from the cases.

It is a little depressing don't you think. My 175 is flat out at around 60. Why the fasination with fast. 60-70 is all that small capacity bikes do. Not bad really considering the work the motors doing. I got a big reality check from my DT several years ago. It broke down (entirely my fault for not routing a wire properly) and i had to push it home. From that moment i have never questioned the performance of an engine, (so long as its running well of course). Surely the point of a cruiser is to cruise. I can make my DT pretty big when i need to if the traffic is getting carried away and people still crap themselves when 6ft and counting heads their way in bike kit looking like a Mad Max refugee

Hang on champ, if you have never pulled a smoker down slow up. They ARE a different animal. The rod having side play but no vertical movement sounds fine, up to 2mm or .0787in is fine. The rings on a DT can have a gap of anything from 3mm .1181in to 8.5mm .3347in and be within spec depending on model. A 78 US spec 125 'should be' around 4mm .1770in for the top ring and 5.5 .2165in for the bottom ring. Its the installed gap thats more important. Thats more like .15 to .35mm or .0059-.0138in for both rings. By installed i mean compress the ring so it sits in the bore, then using the piston push it into its normall working area in the bore and check the gap. If there is a pronounced lip at the top of the bore you can feel with your finger it may be the bore is worn too far (normally they sieze first though ). A far simpler method for checking the rings, if the piston sides are as black well down past them they've had it.

The only question i have is this, perfectly straight genuine question. They are in trouble and are expecting help from us, what if WE needed help?

Thats their only flaw, big doesent mean better with 2 strokes. By the time you are up at those cc's the 4 stroke is catching up, sneaking in with driveability and fuel economy that the stroker can't match. Nothing and i mean nothing sounds or smells as sweet as a big smoker running old school expansion chambers though

+1 Like what they are rattling on now with the middle east. "we should do something", with what exactly.

Nah doesent matter at all, more modern 2 strokes like the DTR125 and my TDR250 for example, the carb feeds direct into the cases. 2 strokes are a masterpiece when it comes to how they work. Its all to do with pressure waves, thermal expansion, positive and negative pressure all working together. I love them. Boring (nerdy) info for you. A 125 cc 4 stroke engine takes in around 100cc of fuel/air mix each cycle which takes 2 crank rotations. With the fasinating way a 2 stroke works the 125 takes in getting on for 150cc (yep, more than should actually fit) of fuel air mix on each cycle that happens every rotation. Shows how 2 strokes are both more powerfull and use far more fuel/make far more power than a 4stroke. Why we can't develope them to be clean i'll never know.

Cor thats not being verbally abused on here . Only proper ankers get that treatment.... Its just your type of question is normally a single post, glorified wanted ad thats all. Personally i think its a pipe dream as anything RD500 shaped, even ringers on e-bay are selling for 3500quid upwards. Genuine low mileage UK bikes can go heading for twice that, more if they have some fancy history or are REALLY low milage. They have some silly quirks too, cranks die at or around 20000 apparently, the exhaust cooks the rear shock as it sits between the bottom pipes under the motor. The engine is really sensitive to set up, 4carbs and 4 powervalves, which all have to work precicely together but you are hamperd buy induction differences between the front and rear cyl's. As to finding one to do up...... I wish you all the luck in the world with that, fellow i got my TDR250 from had one he'd done up to as new and had bought a busted one for parts and that had took him over 2 years most of which was time spent searching for stuff, the busted up one was a write off and it was apparently a bargain at a 'couple of grand' IIRC, he was selling the TDR to finance finishing off. Best of luck

Yes but it really sucked when we used to reply to a problem, which can sometimes take a while, what with looking manuals or online searches in sites that will give the info and then get bugger all thanks. Esp when if you look in the profile they have been on after your reply. So they have turned up asked the question, got the answer then fked of without so much as a please or thank you. I think the intro bit is a very valid and worthwhile part of the forum and does seem to stop the oneposters.

Lucky sod the only time i get sun riding to work is for about 10 days around midsummers day , mind i am riding to work at like 4am

Its here, 3 positive cases of 'scammel starter button syndrome' showing on the yummy mummies of Loughborough today. More in Northampton Brrrrrilliant....

He deserves a special prize.............

I wouldn't think that 2 stroke pump would lift oil over that distance. It only shifts a tiny amount of oil so drawing oil down a pipe that length is at best a hope. Considering how important the 2 stroke oil is, if the tank will go nowhere else then i'd be blanking the pump off and using premix. Is that engine not a little weedy for dragging a trike chassis around?

Can't help with the fuel issue but 'workshop' would be the place to ask.

No problem i'll see him over the weekend, i'll send you a pm when i know more.

Neighbour of mine is a coded welder/ metal fabricator (like he's certified to work on neuclear/oil metalwork work). If the pipe you have is still in reasonable shape i'm betting he could patch it pretty damn close for nothing like the STOOOOOPID money of that new one. Like i said as long as its still got the original shape, that was the only reason we couldn't save my old DT pipe as my half arsed welding attempts patching it over the years had made it go all half cocked so he couldn't fix it, well he could but i fell lucky and got the new one and that was far easier/better.

It was up in the for sale section for long enough. I have the front end for a DTR i can't give away. A good brake disk too.

This is all over the net and there isn't a definitive answer. If you go through the usual villans as far as it goes a good quality 5wt oil will suffice. Can't say more than that and i don't think there is any real answer as Yamaha are not going to announce whats in it as they want to sell it. Another example of progress or is that profiteering?, i'm glad my bikes are stuck in the 80's

Looks good, biggest problem i can see is the rusty pile of shite you rested it on for the photo's

Sure the red one isn't a CT3, that tank don't look DT to me. The fluted area up to the headstock and the flat sides is more like the CT's As far as DT tanks go they should be the same, you may have a change over tank thats a bit of both MX and twinshock as they would have started tooling for the MX but i think its unlikely. Yes my feeling is you have a CT tank on the red one and a DT tank on the white one. Sorry, mind neither are technically wrong i suppose. Don't help with the graphics though.

Onion breath, with all that student totty round your gaf. Mind you their students so it may be a bonus I deliver to the uni every so often and it has to be the biggest collection of inteligent stupid people i have ever seen.

Loads of usefull info Here. After that this could be worth a look too?

At least your gaurantee'd work now, well money at least. The way our lot run we are on pretty much 30day notice, they want you gone its 30days unless they can catch you with something for 'gross misconduct' which seems to be just about anything they fancy and your gone.

Me too, 50 - 100 - 125 - 175 - 350 - 600 - 250 as you may note from the numbers, i'm a 2 stroke man through and through and its acceleration and riding experience that floats my boat. I'd rather be on a bike at 8/10ths at 70mph than nobbing along at tick over braking the 150mph marker. Like today went past a plod car doing a speed trap, flat out, 8500rpm, motor was screaming peeling into a set of bends. Was i botherd by the plod? nope. I was doing 65mph tops, was i having fun. Oh you bet your breakfast i was....

I sympathise with wanting to go a little bit quicker, but FFS you have a 65mph moped. That bike is supposed to be capable of something like 32mph flat out with about 2.5 hp. Your well above that changing into 4th. You are not understanding what we are trying to say here, there are many, many DT125's that cannot hit 65 mph, christ my 175 can't hit 65mph. Your bike is a long way from slow and to improve you really are polishing a pearl, not a turd. As i have already said, your bike is running a high state of tune now. That will in turn make the bike very sensitive to fuel/air issues which can and will KILL 2 strokes stone expensively dead. With the stock airbox/filter yes you will loose a little bit of power but the engine will be safer for it. The biggest point though, your expert telling you to fit this that and the other, you do realise that a freeflow filter increaces air speed in the carb and REDUCES torque and would ultimately make your bogging problem worse.