Oil Injection

[Milan]

I saw this on the FB Suzuki forum.

Imagine if Yamaha did this.
All our bike would be ruined

SORRY IT IS LONG



This comes up on a regular basis, if anyone has anything to add or change please post your replies.
The Suzuki CCI oil injection system.
Suzuki's CCI (crankshaft and Cylinder Injection) gives a metered oil feed to the inlet of the cylinder, controlled via the throttle cable, and a fixed flow to the left-hand side main bearing. This second feed is governed by engine revs only.
The feed to the left-hand side main bearing is delivered to the outside of the bearing and flows through to a circular shield fixed to the inboard side of the bearing. This shield holds oil in the bearing until the height of the shield is exceeded then it flows out and is caught in an overlapping plate fixed to the crank. The plate on the crank has an outlet at it's outer diameter that is pressed into the hollow big end pin. The hollow big end pin then feeds the oil to the big end bearing via a drilling in the pin. The oil is then thrown out into the crank case and carried up to the cylinder.
The right-hand main bearing rides in gearbox oil with the seal being INSIDE the main bearing, the opposite to most two strokes.
The right-hand side main bearing is retained by a step on the inside and a retainer plate on the gearbox side, the crank is fixed to the right hand side main bearing by the nut that secures the primary drive. The crank is secured on the right hand side and "floats" in the left hand bearing.
If the CCI system is not used and the motor run on premix the following will eventually cause problems.
The oil shield on the LHS main bearing and the catcher ring on the crank greatly restrict the flow of oil/fuel mixture to the bearing. On most other two strokes running premix there is a hole drilled from the transfer passage to the area behind the main bearing, one on each side. The hole allows the fuel/oil mixture to circulate, back and forth extremely fast, through the bearing as the pressure in the crank case and transfer passage change. This ensures adequate lubrication of the main bearings.
Some Suzuki's of the era were supplied without oil pumps (RL250 for one) and they have the holes drilled from the factory.
From my experience since the early 70's, there is a noticeable difference in the condition of the LH main bearing and big end in Suzuki engines that have been run without the oil pumps.
There are two suggested ways to premix.
1, Strip the engine and remove the oil shield on the LH main bearing and the catcher ring from the crank. Remove the LH main bearing and drill a hole (approx 6mm dia) from the LH transfer passage to the area behind the bearing.
2, disconnect the throttle cable from the pump, run premix. This gives the required oil feed to the LH main bearing and means you can run a small oil tank of 250-300mL. This was done on the factory TS90MX.
Personally, I've never known a CCI oil pump to fail in use and I can't see a reason to remove them apart from racing at the highest level where chasing maximum horsepower requires a different fuel/oil ratio.
Two observations,
1. The system can't be compared to the Yamaha system because AS FAR AS I AM AWARE Yamaha only fed oil to the inlet. Removing their system does not affect the main bearings.
2, I believe that most claims of removing the CCI system and having the motor last for "years" and thousands of miles are exaggerations.
In Rick Sieman's (Super Hunky) book "Monkey Butt" he describes rental bikes at Indian Dunes (or Bay Mare, can't find my copy) MX track in the early 70's. They found the best life came from Suzuki TS 125's and 185's with the CCI system in use!
Final thoughts, my TS90MX has CCI and premix, my TM125 is being rebuilt and will have the missing CCI system replaced, my RL250 has been modified to run the CCI pump to feed the LHS main bearing only and runs premix.

[m in sc]

why? some kaw triples have slingers (referred to as oil shield below)  and can be run on premix if the slinger is removed. my t500 doesnt have the slingers and could be run on premix no problems. if you pull the slinger on cranks that have them...... it will be fine on premix. However, i always prefer the pump when its an option

[Brad-Man]

Seems to me that because the CCI system directly lubes the crank that it would be superior to the Yamaha system...

[m in sc]

more complex though. my t500 has 4 oil lines to the motor.

[quocle603]

why? some kaw triples have slingers (referred to as oil shield below)  and can be run on premix if the slinger is removed. my t500 doesnt have the slingers and could be run on premix no problems. if you pull the slinger on cranks that have them...... it will be fine on premix. However, i always prefer the pump when its an option

I remember when a bunch of guys gave you a ration of crap because you made that comment about the t500 being able to run premix.

[m in sc]

right? I mean, it can. not like I actually tore the crank down myself or anything...   

the small kaw triples can as well. However, direct fed bearings work well.