1980 RD 350 LC (4L0) problems / modifications.
During '80, the RD350LC had problems with exhaust studs breaking, exhaust pipes craking, acceleration problems (mid-range misfire) and too rich oil pump. These pipes breaking were the result of engine movments and too fragile pipes.
To resolve these problems, YAMAHA propose during '80 to replace pipes (reinforced) under warranty, new carbs settings and new oil pump setting.
'81 & '82 RD350LC models were sold with the following evolutions: new cylinders, new carbs (stamped 4L0-01 instead of 4L0-00 for the '80 one), new exhaust mounting on cylinder & new pipes (differents from the solution proposed during '80 ), add 2 tie rods fixed to the underside of the crankcases and extending forward to the frame and new red valve . There were 2 types of front brake calipers.
So there was 3 different solutions of exhaust mounting from '80 to '81.
| The 4L0 models never had calorstat in the cooling system it's why during winter with cold temperature, they have difficulties to reach the good temperature level. To solve that, Here is a solution commonly used -> |  |
Evolutions guide
|
PART
|
First '80 model |
'80
modification
|
'81
& '82 model
|
|
Carbs
|
Main
Jet 140 done by dealers
|
||
|
Oil
pump
|
stroke
adjustment done
by dealers
|
||
|
Cylinders
|
-
|
No
|
|
|
Pipes
|
-
|
||
|
Reed
Valve
|
-
|
New
after 4L0
- 004669 in factory
|
<-
|
|
Engine
tie rods
|
No
|
No
|
Yes:
Identification
|
|
Brake
calipers
|
-
|
<-
|
|
|
Front
fork
|
|||
|
Swingarm
axle
|
No
grease nipple
|
No
grease nipple
|
Differents shock absorber (4L0-00 for '80 and 4L0-10 for '81 and '82 ?): #1 & #2
Here are documents that YAMAHA communicated to his dealers during '80:
|
Exhaust
system (in English)
|
Exhaust
system (in English)
|
 |
 |
|
Exhaust
system (in French)
|
Exhaust
system (in French)
|
 |
 |
|
Carbs
/ oil pump setting (in french)
|
Carbs
setting and new valve reeds (in English)
|
 |
 |
|
Carbs
/ oil pump setting Air inlet in German and English
|
|
 |
|
