Where does the oil get injected on a Yamaha?

Waterfoul

Waterfoul

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We are trying to figure out what happened to my motor. At what point does the oil get injected into my 97 Vmax 600?? Into the crank? At the carbs? Where? Also, where is the oil pump located and is there a way to tell if it's working... can it be bench tested?

Upon closer examination of my bad piston, part of the edge is burned away at the exhaust port... and the entire forward half of the piston is worn and scratched.

Thanks!

Mike
 
I'm going from memory here. On my 700 there were three points in the crank case where the lines connected from the oil pump. Another line went from the oil pump to the fuel pump for mixture with the gas before going to the carbs.
 
Yup. Put a 50:1 mix in the fuel tank, take the line off the fuel pump that goes to the oil pump, start the motor, pull the oil cable out of the adjuster all the way and hold it and see if you get oil to "burble" out of the open end. Sounds to me that you had a meltdown due a lean condition.
 
Oil is injected in the fuel pump, mixed then sent too the carbs.

Yea sounds like a lean cond. if she melted on the exh. side
 
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You mean when the motor is running? I'm not sure, I suppose you could but it would be a pain and a little risky because your either not going to be getting the crank lubed or there will be no oil in the fuel. You think there's an issue with oil getting to your pistons? I would think it would be easier to just keep it turned off, give a bunch of pulls, open up the air box and check the condition of the fule in the carb bodies. Maybe someone here can check their service manual to see how to test the oil pump.
 
No no no! Not with the motor running... my thought was to pull the plugs right out of the head so it would pull easy... then pull a hose off somewhere and see if oil comes out when pulling on the ripcord. Kinda a two man job probably... one to pull and one to watch
 
I guess I'll be siphoning gas when I get home then! Yum... NOT! LOL!!! I'll have to get some fresh gas... premium too now... the new head gaskets measured .32" and the old stock ones measured .64"... that's HALF as thick... Man this thing is going to rip if I ever get it started!!

What about a little coolant in the crank case... I just couldn't get it all out... no matter what I did there was still some in there. Will this just burn off?? The resident sled head here at work figures this piston burned down due to coolant in the cylinder... or no oil... but if there were no oil the other side would have been damaged too (at least that seems logical)... but a leaking head gasket could ruin only one side... same theory for the oil... if one side why not the other?? I'm gonna pull the bowls off tonight and check the primary's for debris.
 
A small amount in the crank shouldn't kill ya, I believe it would have more of an effect on the crank bearings than the piston. If no oil in the gas then why isn't there damage to both pistons. The piston melting at the top on the exhaust side is an indicator of a lean condition. Have you cleaned your carbs lately? Have you made jetting changes?
 
trying to remember what is in there for jets... I'm so used to big blocks that the numbers don't stick in my mind... ask me what are in my Holley 4150 double pumper and I have no problem.... 89 primary and 91 secondary!!
 
Waterfoul said:
the new head gaskets measured .32" and the old stock ones measured .64"... that's HALF as thick...
Click to expand...

where did you get your HG from???

Post some pics of your piston.
 
bluehammer said:
Yup. Put a 50:1 mix in the fuel tank, take the line off the fuel pump that goes to the oil pump, start the motor, pull the oil cable out of the adjuster all the way and hold it and see if you get oil to "burble" out of the open end. Sounds to me that you had a meltdown due a lean condition.
Click to expand...

This is basically the way the tech manuals will tell you to check pump output. You have to catch the oil in a cc vial at an idle and then do it when the pump is wide open(pulling the cable out of the adjuster)and catch that amount of oil. There are + and - specs that go with the amount of oil that is caught in the vials. Not very complicated, just a big pain. Siphon all of your fuel out and mix up a gallon or so of 50:1. Then start it up and see how it goes.
 
Well it's not going to happen tonight like I planned... the girlfriend just called and feels neglected these last few days (a week is more like it!). So I'm off to do something to, I mean WITH her. Might be able to get back to it tomorrow or Sunday. If she didn't have that stinkin torn ligament... no dancing for her for a while.... the next 6 months should be interesting.... :ORC
 
While we're on the subject, you should take a look at Bender's direct oil injection kit.

"Bender Racing's oil injection kits synchronize the amount of oil used with the throttle position by injecting oil directly into the intake tract instead of into the fuel pump as with the stock system. Our oil injection system ensures more consistent performance, less plug fouling and more forgiving jetting than with the stock set-up. Other, cheaper systems inject oil into the fuel line. Don't be fooled, this method is not direct oil injection and will not correct the lag time before the oil mixes with the fuel remaining in the float bowls. Don't compromise; use only Bender Racing Oil Injection systems."
 

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Yea i always preferd the direct inj. method thats what i like about the older
Yammies,,pumped oil right into the intake boot!! the more throttle the
more oil thats pumped in.

Thats how the PZ's are oiled
 
I've run that Bender injection system. Never had a fault with it. The interesting concept with this system is this: You're sitting on the lake idling with your buddies. The oil in your carb bowls is just that : oil from the pump on the low end of oil metering, thus not having the oil that you would on the midrange or top end. So you line up and take a blast down the lake. The initial mix that you are running on is leaner because of idling. You don't get the heavier oil ratio in the bowls 'til the oil pump puts it in the fuel pump and the fuel pump puts it in the carbs. Now I suppose that the bottom end of the motor has enough oil in it to compensate for the lean oil mixture in the carbs til the correct mixture gets to the motor. But in theory, the concept is better than oil mixed in the fuel pump because the oil directly injected into the carbs is closer to the mix needed for what rpm is now at hand.
 
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