DT125R ARCHIVE

Calum122 · Guru

4DL TZR Engine Unmaintained!

NORFE · DTR Trusted Engine Builder

WHAT DID U PAY FOR IT CAL

Calum122 · Guru

Alot. And i already know what you're going to say NORFE. I always pay too much

He wanted £350. I paid £300

NORFE · DTR Trusted Engine Builder

lol plus 250 for the full rebuild, u puting it str8 in urs?

did u get the cdi with it aswell

Calum122 · Guru

Yeah. I've allocated about £500 for the rebuild.

No. I'm not going to bother with the cdi. He's got one for £40. But i've spoken to scrin and nev and provided you run the dtre servo you'll have no problems.

NORFE · DTR Trusted Engine Builder

okidokey...500 bloody hel what u doin to it lol

full rebuild in spares costs 200 ish inc clutch plates, all bearings,gaskets seals, con rod, piston rebore smile

Calum122 · Guru

Nothing but the best mate. Wossner con rods and koyo bearings. And port and tune the cylinder.

I value your opinion though NORFE.

NORFE · DTR Trusted Engine Builder

a wunt bother just get pattern parts, just as good as any other save ur self the money u will notice NO difference at all using top priced parts only thing ull do is be gutted wen it/if it blows up after all u spent on it

smile

Calum122 · Guru

PMJE then mate?

I only want reliability mate. The engine is going to be tuned so i want strong reliable parts. And i assume you'd have no reason to tell me false information.

Calum122 · Guru

Yeah and pfft. It's only going to be a toy NORFE. Literally thats it. I'm going to keep my bottom end standard for when this 4DL seizes. Run the 3MB00P on the standard bottom end. And run rhe 4FU on the 4dl.

Reliability isn't going to be an issue to br fair.

Edit: lmao! Just read my previous comments! Talk about contradicting myself. I only want reliable parts lol. Reliability lmao. Such a fanny some times. Oh god. I'm leaving it up there cause just shows how dumb i can be lol.

No let me clear it up. I don't care about reliability. The engine won't be going in till next year once i've Got a car. This is literally going to be a toy. Just want nice strong parts that can take the extra strain on the engine.

And i'll be keeping my old bottom end and the other 3mb00p cylinder standard. So i can swap them over straight away in case it goes poP.

-- Edited by Calum122 on Saturday 20th of July 2013 07:18:35 AM

NORFE · DTR Trusted Engine Builder

all off ebay or yambits thats were i get all parts from

mitaka piston

pattern conrod

koyo mains

pattern seals

pattern gasket

black head gasket

only thing that makes it reliable is running it std, the sate of std tune of that engine will run far better than urs now any way so just rebuild it and leave it std

soon as u start messing it makes it unreliable

u rebuilding it ur self

DT-R_bradders · Guru

see i still think the porting on the 4fu barrels are better just look at the differences...

so much more care has been taken with the casting of it..

my 4fu barrel

and the ports are bulging out the sides alot more on the 4fu

cal get it cleaned up inside thos ports n lets av a look m8y

-- Edited by DT-R_bradders on Monday 22nd of July 2013 07:50:38 PM

-- Edited by DT-R_bradders on Monday 22nd of July 2013 07:51:07 PM

Calum122 · Guru

And the saga continues.

It's starting to look a bit better!

The head and cylinder skimmed

slob · Guru

Glad to see you are cracking on with the engine build you have been planning. I take it you will build this one and have it ready for when the one in your bike breaks ect?

looking forward to seeing this develope apart from the grime ect can't see how that engine couldn't be a beutiful engine.

Calum122 · Guru

The plan is is to get this engine running beautifully with a nicosil barrel i've got thats already spanking. The idea is to get this 4dl engine and nicosil barrel running as much brake horse power as possible. Aiming 20+ will get it dyno'd and post piccys. I'm keeping my expectations low. Its not going to be as fast as that YZ. Thats a given.

Then the engine in my bike. Its running lovely. Just low on compression. I'm going to take this 4DL top end. 3MB00P. Rebore and wossner piston. Everything else standard. Bang it on the the dt bottom end. And this will be the reliableish engine. It's never let me down so thats good. I'm going to order a 30mm Mikuni carb and jet to suit for the 4DL and just use the 28mm on the 3mb.

Store the reliable engine for when the 4dl breaks down. And at least then it's a days work for me to be back on the back wheel.

slob · Guru

Sounds a good plan mate. I take it this is an older more powerful engine compared to the later restricted onEs. Do you think reliability will be a big problem given you know how to service and you are not some muppet red lining it continuously?

Calum122 · Guru

Yeah. I'll get some photos of my 4fu as well. How can i clean the transfer ports via conventional methods? White spirit?

DT-R_bradders · Guru

DT-R_bradders · Guru

can try that m8 get an old tooth brush in there if u can..

Calum122 · Guru

I'll put my two side by side when i get home.

DT-R_bradders · Guru

kl

DT-R_bradders · Guru

have u got a normal 3mb head aswell cal take a pic of thos side by side

Calum122 · Guru

Some comparable photos of the 4DL 3MB00P and the 4HW 4FU00

First a quick video if you find this more useful.

I don't know whether that's clear on the photos but those transef ports on the 3MB are DEFINITELY bigger. HOWEVER the 3MB doesn't look anything special. I.e. nothing that couldn't be done to the 4FU. Remember! the 3MB00P is not the TZR-RR SP barrel. This is just a ported 3MB. So I reckon if you get the 4FU ported you could match this 3MB

Anyway I'm really basic at this so i'd be interested in seeing what you guys think.

Calum122 · Guru

The easyest explanation of 3MB v's 4FU Inlet port angle area is this.
You stand in a long corridor, at the end is a door, you are just slim enought to fit through the door (in this scenario lol)

With the 3MB the door is facing you, you walk down the hall & through the door. easy
With the 4FU the doors the same size, but the corridor approaches from an angle.(ie the hinges on door are close to you the handle further away). You can no longer simply walk straight down the hall & through the door. Because even though the doors the same size, the same flow, ie you, cant pass through because the angles changed.
Thats the problem the 4FU has, almost identical port windows, but the wrong angles.

The 4FU i'd use if I was running in low rpms & wanted some extra torque & the 3MB/p id start with for h.p & higher rpm performance.
And I agree a 4FU could be ported (window size) like a 3MB but the main & aux inlet port widows angles are too restricted & rear facing so itl'll favour the lows, My friend has the 4HW and he wanted his 4FU to match the 3MBp but without filling in transfers & heavy reshaping its not possible. I have both barrels here. The port maps are very near identical is just the mean port angle areas & flow are quite different. Aswell as different squish band types. Contrary to the article I was under the impression the 3MB/p ran 6.75:1 Corrected Compression Ratio & the FU ran 7.1:1 CCR?

Thats a message i received off a lad via Youtube. I don't know how correct it is but it's very informative.

BigPhil · DTR Senior Member

Does the tzr lump make a big difference then ? Guessing it just bolts in ?

I'm getting ideas lol.

Calum122 · Guru

This is a special tzr engine. But yeah. The 2rh engine drops in. Should do a ton with the tzr engine.

ShaunyBoy · Guru

So jealous cal :(

Calum122 · Guru

Lol box ing what would you know. This isn't a normal engine.

bit.ly/17XeHGN
bit.ly/14nhT1s
bit.ly/17XeP9b
bit.ly/17Xf1oZ
bit.ly/17Xf2td
bit.ly/17Xf6ZX

Have a look through those. And you'll see what it's worth. My engine came complete. Gearbox all the gears. Fly wheel generator starter cylinder. Cylinder head. Powervalve powervalve motor. Inlet manifold. Fck me i mean it's £300 if i break the engine for parts. So i'm struggling to see how you think it's not worth the money.

Yeah you may not have paid that much for it i appreciate that. Bur at the price it was going for it was worth it all day long. I've seen them go on ebay for more than that before.

scrimsmustang · DTR Mechanic

Calum122 wrote:
Lol box ing what would you know. This isn't a normal engine.

bit.ly/17XeHGN
bit.ly/14nhT1s
bit.ly/17XeP9b
bit.ly/17Xf1oZ
bit.ly/17Xf2td
bit.ly/17Xf6ZX

Have a look through those. And you'll see what it's worth. My engine came complete. Gearbox all the gears. Fly wheel generator starter cylinder. Cylinder head. Powervalve powervalve motor. Inlet manifold. Fck me i mean it's £300 if i break the engine for parts. So i'm struggling to see how you think it's not worth the money.

Yeah you may not have paid that much for it i appreciate that. Bur at the price it was going for it was worth it all day long. I've seen them go on ebay for more than that before.

Cause its a normal engine. Its just an old late 80,s early 90,s DT125RE TDR125 bottom end with the TZR tall gearbox in it, nothing special at all except the topend and any old DT topend could be ported to match or better.

Luke · Guru

Should have gave the geezer a negative to warn future customers. That's what the feedback is for. Stop being soft on them.

Should have at least chased him for a part-refund. Not worth £300 IMHO.