Oil injector pump Suzuki TC100

I've been working on getting a '74 Suzuki TC100 back on the trail.  I got it pretty much ready to ride except the injector oil pump is not working.  The pump is inside the crankcases and replacing it would require a complete engine disassembly to split the cases.  Don't want to do that.  Can I just run pre-mix in this old bike?

I've been working on getting a '74 Suzuki TC100 back on the trail.  I got it pretty much ready to ride except the injector oil pump is not working.  The pump is inside the crankcases and replacing it would require a complete engine disassembly to split the cases.  Don't want to do that.  Can I just run pre-mix in this old bike?

 

On this particular model with the CCI injection, it is required for proper lubrication of the crank and rod bearing.  You cannot reliably run pre-mix with this type of system.

 

You can read more about this here all about 2 stroke oil injection systems  (there are diagrams and explanations)

 

Actually it does not require a complete dis-assembly of the case, however it does require some basic mechanical aptitude and tools.  It is located just behind the countershaft.  Most common problem is the system probably just needs bled of air.  READ your service manual for proper procedure.  This is common on bikes that have had the oil tanks run dry or have been sitting for long periods of time (10 years+)

 

On rare occasions the plastic gear that drives it (off the primary gear) might be broken, but if that is the case you would still need to remove just the cover to get the broken pieces out (this is very rare and probably not the case).  

 

 

 

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Edited by thejunkman

Well rats, I was hoping this wasn't the case.  I'll take another look at it.

Excellent explanation by the Junkman on the Suzuki CCI system.  My 1976 TS100 (only 600 miles but it had sat for 33 years) had the opposite problem, the injector pump was running at maximum output at all times and drowning out the engine/spark plug with oil.  I also don't think that the check valve in the intake was working.  According to the factory shop manual you can disconnect the cable and run the injector at the slowest output as long as you run pre-mix to lubricate the cylinder (the crank only needs minimal oil flow as oil collects in this area and isn't completely pulled into the cylinder intake).  This was an option if you installed the factory MX kit.  I blocked off the oil line running to the intake completely (replaced the hollow oil through bolt with a solid standard bolt) and this solved my issues - the bike runs great, doesn't fol plugs and seems to have the proper lubrication.

 

I've also read that the failure mode for these oil injection pumps is to go to max output but I don't know if that is a fact in all cases, but it certainly was in my case. 

 

Best of Luck!

Suzuki had what they called an oil guide plate on the crank next to the bearing that fed it oil. You can replace the plate with a shimming washer of the same thickness and run pre mix. This was done first on the RM 125 M.

Good point - removing that plate in the crankshaft assembly is required to completely eliminate the oil injector system.  In my case definately not worth the trouble since the rest of the engine was in fine shape.

Good point - removing that plate in the crankshaft assembly is required to completely eliminate the oil injector system.  In my case definately not worth the trouble since the rest of the engine was in fine shape.

On the motors with the plate between the main bearing and the crank,(not rotary valve motors),  that would be the ONLY correct way to convert it to premix is to remove that plate.  Suzuki calls it an "oil guide plate".  It keeps and holds injected oil behind it a little longer but if you don't remove it and use premix, now it partially shields the bearing from getting exposure to the premix.  Of course you've got to TOTALLY split the cases to remove it and if you're that far, you might as well put in new main bearings and seals.

Hey junkman, Thanks for the drawing you provided. Skeptics should note the main bearing on the clutch side of the motor is lubricated by the gearbox oil.  The seal is between the bearing and the crank.  I don't know how many discussions I've had with people who say gearbox oil has nothing to do with the main bearing.  Well, it DOES.  But think about it.  This should give a person incentive to change their gearbox oil more often.  Think about all that gear and clutch debris lubing the main bearing!

Hey junkman, Thanks for the drawing you provided. Skeptics should note the main bearing on the clutch side of the motor is lubricated by the gearbox oil.  The seal is between the bearing and the crank.  I don't know how many discussions I've had with people who say gearbox oil has nothing to do with the main bearing.  Well, it DOES.  But think about it.  This should give a person incentive to change their gearbox oil more often.  Think about all that gear and clutch debris lubing the main bearing!

Great point and also a reason that the clutch side oil seal in this design will last a lot longer than the ignition side oil seal - assuming the oil is changed regularly!

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