DT125R ARCHIVE

endurodt125 · DTR Respected Member

RE: 1999 yz/dtr 170cc athena hybrid build

Calum122 · Guru

Measure twice cut once as they say.

scrimsmustang · DTR Mechanic

If you heat seized it it was running lean, must have been running lean on the needle as you wont of been hammering it if you were running it in.

endurodt125 · DTR Respected Member

when out with my mate on hes rm and the bike had only done about an hour and i thrashed it a bit trying to keep up then the exhaust started blowing at the stub so i rode home left it for a couple weeks then went to fit a new exhaust and noticed the piston was scored up the exhaust port ...took it apart and noticed the head gasket was slightly leaking probably from being over torqued (my torque wrench is ****e) ,i was still in the process of test running it so hadnt quite worked out the kinks so maybe jetting was wrong well probably was anyway long story short the piston had nipped up on the exhaust port side theres a tiny bit of nickasil missing and the piston is no good but rings look ok (not going to use them ).....basicly im a numpty ha .......its going off for a replate at the end of the month and ordering a piston and little end bearing, just got to get this 3mm skimmed of the top of the barrel first. and then the first thing im going to do when its back together is some plug chops! lol

endurodt125 · DTR Respected Member

Little update got a R&G shocktube and a new piston ..getting the barrel skimmed at some point soon then it's off for a replate

endurodt125 · DTR Respected Member

Hmmm thinking about getting a sleeve fitted to my 170 kit so It can be rebored but Athena don't make oversize pistons ...does any one know if the dt/wr 200 pistons fit the 125 Conrod?

-- Edited by endurodt125 on Tuesday 3rd of March 2015 04:09:57 PM

endurodt125 · DTR Respected Member

Anywho I got a quote for the barrel

endurodt125 · DTR Respected Member

Just dropped the barrel of at the enginneers ..should be getting a call sometime Monday :) then off for a replate at the end of the month and then I can start putting her back together :) happy days .....p.s no one's showing me any love on here ! Lol

FunkeyMunkeyDavid · Guru

we're all holding our breath waiting on the outcome bud

endurodt125 · DTR Respected Member

Haha what for when it goes bang lol?

FunkeyMunkeyDavid · Guru

lol that bits a side show biggrin

if you manage to make the athena kit work,there will be a massive flurry of monkey spanking/kit ordering on here

Calum122 · Guru

Nah I'm keeping my fingers crossed for you pal. Should be interesting.

endurodt125 · DTR Respected Member

Just spoke to the enginneers they said there only going to charge me £20 quid ..happy days :) ...I decided only to get 2.5mm taken off because I'm paranoid lol also been thinking about getting some port work done so I'm going to email Mick Abbey at some point today

Calum122 · Guru

For plated bores you will need the plating stripped before he will do any work to it

endurodt125 · DTR Respected Member

Ahhh I see ,thinking about it I'm not going to notice the corrected port timings if I get it ported so I'm probably going leave it for another time

endurodt125 · DTR Respected Member

Well it's done there's no turning back now lol ...they even cleaned it all up for me :)

Calum122 · Guru

Sweet mate. This is going to be mint!!!

Watching this space.

endurodt125 · DTR Respected Member

I would have it running on the weekend if it wernt for this little ****er (see pic) :( any who I polished the exhaust port today I'm pretty happy with the result

Calum122 · Guru

That exhaust port lmao. That shouldn't be too noticeable power increase. But should prevent carbon build up, and otherwise looks sweet haha!

Oh if I were you mate, ditch the oil pump and go premix. Would br my advice.

endurodt125 · DTR Respected Member

Hahaha I got bored at work lol and I already have dude I don't trust oil pumps I always premix 😏

Calum122 · Guru

Weird. Maybe switch back to oil pump then? Isn't that why it failed?

Yeah I'm looking forward to this good luck.

endurodt125 · DTR Respected Member

Nah wasn't that ,it was overheating there was a few things wrong that could of caused it but I'm going to make sure everythings a 100% this time

Calum122 · Guru

What? Really? How did it overheat? Incorrect jettings I take it?

What you going to use as a spacer? You could probably get away with doubling up the base gasket.

endurodt125 · DTR Respected Member

I made a spacer out of ally , I was still test running it because it seemed to be getting hot and then when I last went out on it the exhaust came lose at the stub and I had to ride it home so that wouldn't of helped plus when I took it apart I noticed the head gasket was leaking slightly ...I didn't even get a chance to do any plug chops :( I didn't even know it had seized till I went to fit a new exhaust ,I looked up the exhaust port and the piston was scored and I cryed a little haha turned out it had nipped up right at the bottom of the exhaust port ,it was still running fine so I had no clue :( I'm running oversize yz rads and it's still getting hot :/

Calum122 · Guru

Sounds like a jetting issue. My brother ran his Athena kit on stock rads for ages and it was fine.

You probably won't believe this, but at the time my brother bought his, the cylinder was ruined and the piston rings had melted into the piston. He was mega upset, but despite this he filed it back down and still ran it. Bodged job galore but simply Coul take a beaten

endurodt125 · DTR Respected Member

Hahaha proper job , yer I'm running a 32mm with the yz airbox and a 250 main so the jetting was probably way out but I've got a few jets here that I can play with when it's back together :) I always knew it would be hassle to set right but I just wanted to ride lol

Calum122 · Guru

He ran a 38mm yz carb on the 170 kit. Was dirty on fuel but delivered the power nicely.

endurodt125 · DTR Respected Member

How he manage to get it to fit manifold ,I had trouble fitting the 32mm and tbh I would of thought a 38mm would be way to big? Did he lose a lot of bottom end? Just literally sold a 38 mikuni on eBay lol

Calum122 · Guru

Used a whole saw to bore out the inlet manifold.

Personally, from what I've read, 38 is too big. But that would be for a 125. 170 maybe okay.

I can't comment really, never had the servo set up so it was literally gutless below 6K rpm. Then okay past that. It was 'rapid' at the time. But I know bog standard 125's that were faster, my fully restricted 125 wasn't too far behind. One thing the Athena did have going for it was a more torques. Was torqueyer and I think that is what they're.

Calum122 · Guru

In the first video you can hear it's over fueling like mad, but the second I think he sorted it.