RT100 cylinder questions?

[britx303]

New guy here........lurking for awhile. My daughter and I have an RT100 that we've had for 5 or so years. Im looking to confirm what years MX100/DT100 cylinder and heads are the correct years to get for getting a little more out of the bike, since Im the one that will be racing it in hare scrambles.........she has a ttr125 for racing. So far Ive opened up the stock exhaust and gutted it,rewelded it back and bored out the stock "silencer". Removed the head gasket. Only had to raise the needle and back out the air/fuel screw so far,but a size or 2 up on the main will be along soon........gets a little lean WOT. So far the RT has become a completely different bike for the better........lofts the front wheel easily?. So back to the topic of engine stuff............what are the proper years MX/DT cylinders and heads for swapping onto the RT? Ive searched here,but have found mixed results. Thanks!!

[motoxvet]

If you don't get an answer here & since you might be able to use a DT part, check out yamaha-enduros.com.  There used to also be a yamahaenduro.com but I don't see them any more.  They might have disappeared from the net but I got some good info from them for my DT-250's.  See if you can find them too.  You might discover the best way to up the performance is to do a proper squish machining on one of the heads you already have.  

Edited December 29, 2019 by motoxvet

[britx303]

Thanks,ive been trying to look over that site too. There were some other guys heading down a similar road with RTs using the DT/MX stuff on that enduro site,but their threads never seem to finish up with the end results......or at least I never found a completed thread. The race is 1 week from today,so this will have to be an afterwards job and run it like it is for this round if I cant confirm which parts are the good ones to get and have them delivered asap. 

[S.O.A.N.Z]

Partzilla

This Yamaha 3A3-11311-01-00 CYLINDER 1 Not Available fits the following models and components:

Yamaha Motorcycle 1979 DT100F Cylinder & Crankcase

Yamaha Motorcycle 1978 DT100E Cylinder & Crankcase

Yamaha Motorcycle 1980 DT100G Cylinder & Crankcase

Yamaha Motorcycle 1992 RT100D CYLINDER HEAD

Yamaha Motorcycle 1997 OFF-ROAD (INK BLUE) - RT100J CYLINDER HEAD

Yamaha Motorcycle 1996 RT100H CYLINDER HEAD

Yamaha Motorcycle 1999 RT100L (DEEP PURPLISH BLUE SOLID E) CYLINDER HEAD

Yamaha Motorcycle 1995 RT100G CYLINDER HEAD

Yamaha Motorcycle 1998 RT100K CYLINDER HEAD

Yamaha Motorcycle 1990 OFF-ROAD - RT100A CYLINDER HEAD

Yamaha Motorcycle 1993 RT100E CYLINDER HEAD

Yamaha Motorcycle 1994 RT100F CYLINDER HEAD

Yamaha Motorcycle 2000 RT100 - RT100M CYLINDER HEAD

Yamaha Motorcycle 1983 DT100K Cylinder Head & Cylinder

Yamaha Motorcycle 1982 DT100J Cylinder Head & Cylinder

Yamaha Motorcycle 1981 DT100H Cylinder Head & Cylinder

[britx303]

On 12/30/2019 at 12:59 AM, S.O.A.N.Z said:

Partzilla

This Yamaha 3A3-11311-01-00 CYLINDER 1 Not Available fits the following models and components:

Yamaha Motorcycle 1979 DT100F Cylinder & Crankcase

Yamaha Motorcycle 1978 DT100E Cylinder & Crankcase

Yamaha Motorcycle 1980 DT100G Cylinder & Crankcase

Yamaha Motorcycle 1992 RT100D CYLINDER HEAD

Yamaha Motorcycle 1997 OFF-ROAD (INK BLUE) - RT100J CYLINDER HEAD

Yamaha Motorcycle 1996 RT100H CYLINDER HEAD

Yamaha Motorcycle 1999 RT100L (DEEP PURPLISH BLUE SOLID E) CYLINDER HEAD

Yamaha Motorcycle 1995 RT100G CYLINDER HEAD

Yamaha Motorcycle 1998 RT100K CYLINDER HEAD

Yamaha Motorcycle 1990 OFF-ROAD - RT100A CYLINDER HEAD

Yamaha Motorcycle 1993 RT100E CYLINDER HEAD

Yamaha Motorcycle 1994 RT100F CYLINDER HEAD

Yamaha Motorcycle 2000 RT100 - RT100M CYLINDER HEAD

Yamaha Motorcycle 1983 DT100K Cylinder Head & Cylinder

Yamaha Motorcycle 1982 DT100J Cylinder Head & Cylinder

Yamaha Motorcycle 1981 DT100H Cylinder Head & Cylinder

Thats the bike I already have......the rt100G. I was under the impression there was a different/older model 100 that had a cylinder with more performance oriented porting,that would bolt directly on to my current rt100 to gain a little bit more "free" HP. Guessing ive already got what I thought needed at this point. Oh well,she's still a fun bike now that its been uncorked a bit. Racing 4 days away.....woohoo.