The Hodaka Club Forum

So, I just put the newly bored cylinder and piston in, put it all back together and started it up, runs grat, started second kick. My brother had suggested that I put a bit of oil in the tank for break in, and then double check to see that the injector pump was pumping oil. I loosened up the connection at intake and now oil flows out as it is running. I pulled on the cable to try to get it to pump faster, and still no oil. Do I need to prime the pump in some way? There is plenty of oil in the tank. Thanks

It does take a while for the pumped oil to get through the hoses as it only puts out a drop at a time. Seems like last time I started with empty lines it took 5 to 10 minutes to get all the way to the cylinder. Is your lines clear so you can see the oil moving in them.

Of course the pump may be bad or someone may have taken out the drive wheel to the pump.

So, this is what I have done so far: drained the oil and put in fresh oil, new clear oil feed lines, removed the pump and blew out a wad of crud, bleed the air out of the input line, put in a new check valve at the carb.
Now I fired it up and it does seem to pump, just very very slowly, like an inch of oil making its way up the line towards the carb every 10 minutes or so. This seems a bit on the slow side to me, pulling on the cable to increase the flow rate did not seem to have much effect.
When I took the pump off I did not really take it apart or anything, other than taking the end caps off to look at things and blowing it out. Everything looked good and clean, did not see anything broken.
If I had a leaking seal on the drive shaft would that cause it not to pump? When I had the pump off I kicked it over and the drive shaft turned.
Any thoughts?

Many would advise that you abandon the oil pump and go with mixed gas exclusively. There is even a block off plate that can be purchased for this purpose. If you strongly wish to keep the oil pump then this is what I have done on several Road Toads.

First, make sure that the line on your pump actuator lines up the the first line on the pump body when there is slack in the oil pump cable. The tang can be carefully bent to allow this adjustment. Once that is done, then verify that the 2nd line on the pump body is reached when the throttle is wide open. The cable is then to be adjusted to begin movement of the oil pump at the exact same time that the throttle cable begins to move the carb slide. Pretty easy to do.

I did what you described. Flushed the oil tank and lines. Filled the tank with injector oil (I use Yamalube 2S). I then bled the input line. Removed the output line at the carb manifold and plugged the hole in the manifold with a short 6mm 1.0 pitch bolt.
I then placed the end of the oil line into a heavy ziplock bag and zip tied the bag to seal it and to secure it down and away from the motor.

I then drained the fuel tank and filled with premixed gas (I use Yamalube 2R mixed at 32:1). After running the bike for several rides, I was getting a steady "drip" of oil down into the bag. Once I was convinced that all was working, I put it all back together and drained the premixed gas and filled with "non-ethanol" gas.

It does take a good bit of time to fill the lines and to eliminate any air in the lines...
Dale

I'll have some information for this thread which attempts to illustrate the "smallness" of the oil volume which gets metered out by the oil pump in a while. It may help on the understanding of the amount of flow one should expect to see. Hope to be able to post tonight.

Ed

OK. Here is the information I said I'd send. I sure hope the photo link works!

Below are two photos (melded into one). The left photo shows 1 cup (8 fluid ounces) of water in a glass. The right photo shows the same glass minus a little bit of water (0.2 fluid ounces to be exact). That is the volume of oil which would be contained in one cup of 40:1 pre-mix fuel.



Using some really loose average information from my own machine. A cup of fuel should carry me about 2.5 miles in 5 minutes (based on guesstimated 40mpg at average speed of 30mph while out trail riding).

Noting that one of the intended advantages of the oil injection was to reduce oil consumption (and hydrocarbon emissions), the oil injection should "inject" substantially less oil than illustrated in the photos under the same operating conditions. THEN, if you do an oil pumping test at idle speed (rather than the much higher engine speeds when averaging 30mph on the trail) . . . you are going to see a very small quantity of oil get pumped.

Dale's quite practical test while running pre-mix seems like an excellent way to confirm that the oil pump is delivering oil . . . and to build confidence that it is doing so.

Ed