Question for RODBOLT

[Key west Tom]

On the topic of the oil injection on a 1988 Yamaha 150hp. I was wondering about the timming of the oil injection pump. Is it timmed? I understand you have said no it is not, but in my book (this is not a book from Yamaha it is a aftermarket book) that i'm using to put the motor back together it said to make sure that I put the oil hoses back in the correct order and to the correct port. If I must put the hoses to the correct port then the pump may be timmed, is this correct? or is the book misleading? Does the oil injection pump pump out pulses of oil or is it more of a steady flow? If it is pulses of oil than I would want that pulse of oil to shoot in at the same time as the flow of air and fuel so it will mix and not just puddle in the intake area, right? One more thing this motor has been compleetly taken apart, crank out and the oil pump drive gear out.<br /> Sorry about reasking this question over again but I just don't want to damage the motor, i'm helping a friend put his motor together.<br />Thanks again for the help,<br />Tom Kelly

 

[Ray Neudecker]

Re: Question for RODBOLT

The oil pump is not timed manually. It does pulse in rotation,so you do need to hook up the hoses to the proper outlets and intakes.

 

[Key west Tom]

Re: Question for RODBOLT

Thanks Ray, If it does pulse and the hoses must be conected to the correct port, how do I make sure the first pulse of oil goes to the intake at the correct time? Rember the crank has been removed and the oil pump drive gear is not in the same mesh with the gear on the crank as it was when taken apart. <br /><br />Once again I just want to make sure I don't damage the motor<br /><br />Thanks,<br />Tom

 

[Ray Neudecker]

Re: Question for RODBOLT

Test run with a small tank with mixed fuel to allow it to synch itself. This also allows you to pull the lines one at a time to be sure the oil has no air bubbles and is pumping properly. You will have to give it a little time to refill the lines.

 

[Key west Tom]

Re: Question for RODBOLT

Yes, I understand how to bleed the system out and I understand the inportance of it. When you say that the pump will "synch itself" what does that mean? Are you saying the pump will get into synch with the position of the crankshaft/ connecting rods?<br /><br />What I need to know is does the pulse of oil that gets pumped to, say, cyl #1 have to be pumped at any one time? Must that shot of oil be pumped at the same time that the air/fuel charge is flowing through the reed valve?<br /><br />Thanks<br />Tom

 

[Ray Neudecker]

Re: Question for RODBOLT

Not exactly it doesn't. It is sucked into the cylinder by the vaccum created by the engine on the up stroke.

 

[Key west Tom]

Re: Question for RODBOLT

Thanks Ray, But I just don't understand if the lines must be installed in the correct order on the pump and to the correct intake port, then it must matter the order, therefor time, the oil is pumped into the intake. If this is true, the whole process must start at the corrcet time. Does this not sound right? If the oil pump will only fit into the pump drive one way becouse of it indexing into the pump drive shaft only one way, please remember that this crank has been removed and the oil pump drive gear is not meshed with the crank gear in the same place.<br /><br />I'm sorry about beating a dead horse like this, I understand you have said the pump is not timmed, but I just don't understand why the oil lines must be reinstalled in the correct order if the timming of the oil injection does not matter.<br />Please contuinue to help me understand, and I do thank you for your help.<br /><br />Tom

 

[Ray Neudecker]

Re: Question for RODBOLT

The oil must be delivered in rotation for each cylinder. That is why the lines are hooked up in rotation. Running on a spiral gear the timing is set by the shaft which has a fixed timing between the shaft and the pump. Makes no difference where on the spiral gear the rotation starts as far as timing. The only way to get it out of time is to hook up the lines wrong.

 

[Key west Tom]

Re: Question for RODBOLT

If the spiral gear is not in the correct position in relationship to the crank, then the the oil line to, let's say #1cyl, will not get it's oil shot when the crankshaft/ rod is in the correct position to receive this shot of oil. Yes the oil distrubtion will be in the correct order, but it would not be at the correct time in relation to crank position.<br /> So, if the oil distrubtion must be in the correct order it stands to reason that it must also be at the correct time in relation to crank position. Yes? No? <br />I understand that the pump and pump drive shaft are indexed in that it will connect only in one position, but remember that the pump drive shaft is not in the same position in relation to the crankshaft becouse the crank has been removed and reinstalled after the pump drive shaft was rotated.<br />I know the exact order the oil lines came off and they will be reinstalled in the same place, but lets say, just for the sake of argument, that the order is that the pump shoots the oil to intake #1 when that piston is in B.D.C. position. then the next shot of oil will go to, let's say #3 intake becouse that piston is at the correct position to receive it's shot of oil. (I do not know the correct firing order or that the piston should receive it's oil at B.D.C. position, but if the order of the oil shot is an issue it must be becouse it needs to follow crank/rod/piston position and that would be firing order I a'm at work and the motor is at home)So let's say this is true, for the sake of argument, If I install the pump and it's drive gear in any position, who is to say the shot of oil will go to #1 intake when the piston is in the correct position to receive it? And if #1 cyl does not get it's oil at the correct time, then the one that should follow it would not get it's oil at the correct time even though it would be in the correct order.<br /><br />I must be able to understand this before I put this motor together, so thanks for helping<br /><br />Tom

 

[Key west Tom]

Re: Question for RODBOLT

Ray, is it just one shot of oil per crank revolution per cylinder? Or does the pump put out many shots of oil per revolution per cylinder?<br /><br />Thanks, Tom

 

[rodbolt]

Re: Question for RODBOLT

dude your killing yourself.<br /> trust me there is no timing of the pump. the check valves must work and the lines need to be in the correct spots but no pump timing. on the old kiev pumps the pump actually "spurts" in pairs. thats why if a pump check valve fails and you add a late style inline valve its imerative to add it to the other one in the pair. but concentrate more on doing the fuel and cooling system. if you have the old style pump with 6 nipples pointing up in a circle now will be a good time to change it to a new style mikuni.

 

[Key west Tom]

Re: Question for RODBOLT

OK Guys I guess that is the final word! I'll put it back with the hoses the same way they came off. <br /><br />This motor is on a boat that a friend just bought cheap. He was told that the motor had a bad knock and that it would need to be rebuilt. We did not want to do any damage so we did not run the motor but we did do a compression test --all cylinders were 110PSI so we thought we would find crank/rod problems or at least wrist pin problems not piston problems. We got the motor apart and it looks very good but it looked like some side wear on the large end of the connecting rods. All this wear was about equal on all rods and is on the bottom side of the rod like the weight of the rod riding on the crankshaft is what made the wear. This does not look like it would make a knock. I think the other owner also said the engine missed (did not fire on all cylinders)also.<br />What do you all think about this?<br /> <br />Thank you for the help and tring to get me to understand this pump thing, Can't say that I do but will do as you say. <br />Thanks again,<br /> Tom

 

[Ray Neudecker]

Re: Question for RODBOLT

These are bottom guided rods and the wear marks are likely normal. Since you have it apart spin over by hand and see if you feel any rough spots during rotation. Mic the cylinders and pistons for wear. Inspect the top and bottom crank bearings also. Note that the knock could be in the gearcase. You really needed to run the engine first to help troubleshoot the source of the problem. Suspect you may be trying to trouble shoot a gearcase or fuel restriction problem rather than a power head recpricating one.

 

[rodbolt]

Re: Question for RODBOLT

replace the bottom main any time the crank is out. after that I am with Ray. usually by the time a wristpin or rodbearing wears enough to make noise its easy to see. its usually the one hanging outside the block. roller bearings are not like sleeve bearings. they tolerate no wear. once it wears enough to get sloppy it self destructs a few minutes later. the roller and ball bearings in a two stroke dont ride on an oil film like sleeve bearings in a car. they actually have to maintain surface contact with the surfaces to allow them to roll. if they cant roll they slide. sliders come out the crankcase rather rapidly.