Yamaha DT50 - DT80 Tuning

[Egebo]

First... Is it possible to fit an DT80(RD80) engine on a DT50(RD50) bike?

And secondly... How many HP can you approximatly get from a tuned DT80(RD80) engine?
And what tunings parts are the best for that engine?

 

[Bas]

If you have an old DT50 you can easy fit an DT80 engine. I don't know about the new models.

Futhermore, there aren't that much parts for DT80, you can fit a 110cc Malossi if you want, and get a 24 mikuni with it.

 

[Ralf]

New DT -> AM6

 

[Egebo]

If you have an old DT50 you can easy fit an DT80 engine. I don't know about the new models.

Futhermore, there aren't that much parts for DT80, you can fit a 110cc Malossi if you want, and get a 24 mikuni with it.

You dont know, how many HP that would provide?

And where can you buy those parts?

 

[Cruz_e_Silva]

There is also a Polini kit for the DT50/80 LC with yamaha engine.
Usualy here in Portugal the mod is very common and it's needed a 42/43mm aftermerket crank and the carters rebored to fit the 55mm cilinder kit on the 50cc model. The 80cc model is not sold here but only in Spain. In this last one it's a straight forward job. The max speed of those bikes is around 160km/h with tuned cilinders.

 

[Egebo]

There is also a Polini kit for the DT50/80 LC with yamaha engine.
Usualy here in Portugal the mod is very common and it's needed a 42/43mm aftermerket crank and the carters rebored to fit the 55mm cilinder kit on the 50cc model. The 80cc model is not sold here but only in Spain. In this last one it's a straight forward job. The max speed of those bikes is around 160km/h with tuned cilinders.

So the Polini (LC) and Malossi (LC) cilinders can be fittet to both DT50(LC) and DT80(LC)?

What about fitting an 100cc (LC) cilinder on an old DT50(AC)/DT80(AC)

 

[markybda]

DT-LC and AC

I do not know if the LC block would fit on a a/c motor because the water runs out of the block into the motor casing (Water pump). I definately know that a a/c block will work on a l/c motor though...

 

[markybda]

1

 

[markybda]

DT-LC and AC 50motor

Whats up Nuno?
I live in Bermuda and have a ? for you. Is the crank that you mention below a DT/RD 80 stock yamaha crank? If not what bike is it from? WHere could I get it? Could you help me out?
You use a italkit block on your bike?
Mark

There is also a Polini kit for the DT50/80 LC with yamaha engine.
Usualy here in Portugal the mod is very common and it's needed a 42/43mm aftermerket crank and the carters rebored to fit the 55mm cilinder kit on the 50cc model. The 80cc model is not sold here but only in Spain. In this last one it's a straight forward job. The max speed of those bikes is around 160km/h with tuned cilinders.

 

[Egebo]

I do not know if the LC block would fit on a a/c motor because the water runs out of the block into the motor casing (Water pump). I definately know that a a/c block will work on a l/c motor though...

So it is possible to mount at 100cc (55mm) cilinder on at DT/RD50 motor?

At this point, dont think about how to get at working waterpump

 

[markybda]

are you puting the 55mm on a a/c or l/c motor? and is the block a/c or l/c?
marky

So it is possible to mount at 100cc (55mm) cilinder on at DT/RD50 motor?

At this point, dont think about how to get at working waterpump

 

[Egebo]

are you puting the 55mm on a a/c or l/c motor? and is the block a/c or l/c?
marky

My plan is to make a fast Yamaha RD50.
So i started gathering info.

I was told that the RD50(AC) & DT50(AC) was the same motor.
and then i was told that the DT80(AC) would fit 100% in the DT50(AC) frame..

All this put together should mean that a DT80(AC) motor should fit a RD50(AC) frame 2.

Now i am trying to find out if i can mount a LC cilender on the AC motor

 

[Cruz_e_Silva]

To Pro-Tuning
1st:You can't put the LC cilinder in an AC (very old) carter because not only the carter is diferent but the the cilinder studs are in diferent places also. You can convert 50LC to 80LC altought.
2nd: I think the LC carter can be put in the RD50 with minor mods to the frame.
I don't know if there is a 55mm cilinder to the 50ccAC models, only know 45mm from Polini.

To markybda
I don't like DT's! Those bikes suck...but here in Portugal they're like the plague...
The crank I speak could be an original DT80LC crank or an aftermarket one. Those ones that are sold here are Italian or even Portuguese (JASIL-TopRacing) made ones I think exclusively for Portuguese market because DT80 are not sold here.
The kits used here are Aluminium Polini and Italkit and few Iron Malossi's.

 

[Egebo]

To Pro-Tuning
1st:You can't put the LC cilinder in an AC (very old) carter because not only the carter is diferent but the the cilinder studs are in diferent places also. You can convert 50LC to 80LC altought.
2nd: I think the LC carter can be put in the RD50 with minor mods to the frame.
I don't know if there is a 55mm cilinder to the 50ccAC models, only know 45mm from Polini.
QUOTE]

The 55mm cilinder im talking about is the 100cc (LC) for DT80
Polini, And Malossi are the brands i have seen

Can you find some pic of the DT50(LC) and the DT80(LC) engins. So i can compare the 2?

 

[lilplaya_bm]

i dont realy know much bout dt 50's but my m8 had one that was fast as hell.... we compared the crank casings to a yz80 scrambler cilinder kit....the studs would need to be drilled in different areas and there would need to be some modifications to the crank case but they can fit.... if this was done then it would be veryfast..... put a 28mm keinh or makuni carb and get a pro circuit fatty pipe and modify that to fit on the frame....u whould need to geta very nice crank though....good luck...it was jus a thaught it wasnt actually done....

 

[Cruz_e_Silva]

Both LC engines are alike from the outside....

 

[markybda]

I have a Dt-50 (LC)... I also have a RD 80 LC... and the rd-80 motor fits perfectly int to dt-50 frame...
I KNOW that you cannot fit the LC motor into the AC frame without modifications...

The 50 and 80 engines are a little dofferent.. like different clutch basket , different stroke (thus the need for a different crank...)
I also know the DT motors have a tighter gearbox then the RD motors... so if you want to go fast, change the box!!!

To Pro-Tuning
1st:You can't put the LC cilinder in an AC (very old) carter because not only the carter is diferent but the the cilinder studs are in diferent places also. You can convert 50LC to 80LC altought.
2nd: I think the LC carter can be put in the RD50 with minor mods to the frame.
I don't know if there is a 55mm cilinder to the 50ccAC models, only know 45mm from Polini.
QUOTE]

The 55mm cilinder im talking about is the 100cc (LC) for DT80
Polini, And Malossi are the brands i have seen

Can you find some pic of the DT50(LC) and the DT80(LC) engins. So i can compare the 2?

 

[Egebo]

Both LC engines are alike from the outside....

I have heard that the DT(LC) engines is the AM6 engins.
Same engine as used on Aprillia RS50

 

[Egebo]

I have a Dt-50 (LC)... I also have a RD 80 LC... and the rd-80 motor fits perfectly int to dt-50 frame...
I KNOW that you cannot fit the LC motor into the AC frame without modifications...

The 50 and 80 engines are a little dofferent.. like different clutch basket , different stroke (thus the need for a different crank...)
I also know the DT motors have a tighter gearbox then the RD motors... so if you want to go fast, change the box!!!

So it aint possinle to make the 100cc(LC) for DT80(LC) fit the RD50?

 

[Cruz_e_Silva]

I have heard that the DT(LC) engines is the AM6 engins.
Same engine as used on Aprillia RS50

You are talkink about DTLC with Minarelli engine, not the DT Yamaha engine that looks like the RD one.
I think it's possible to fit a DT80LC Yamaha engine (55mm to get 100cc from Polini or Italkit) in the RD frame but RD's in here are not like DT's so I can't confirm you that thought.