UPDATE_Help. Need engine tech help.. low oil??

[ReX]

I believe it does have a low oil pressure cut off switch, but sucking air through the oil system likely could still toast a rod bearing if it is under power.

If I recall correctly, it will run for something like 10 seconds without oil pressure before shuttinng down.

 

[stoutner]

Yes, it will run for a few seconds at least without oil pressure.

Make sure you also put the exact same lifters in the exact hole they came out of. They each have their own sized shim. You don't want to mix them up. If you do, you gotta measure clearance for each one and reinstall one by one.

 

[TonyVT]

Oh she's coming apart for sure,, the right way before I do $$$$ more.

Thanks to all you guys for your input...

Its got to be a bearing and because I didnt run it any further it didnt go.

Lots of bronze colored metal in there!!!!!!

look at this http://s95.photobucket.com/albums/l157/TonyAudet/oil/

Can the head come off as unit or does it have to be completly dissasembled? I may take it down to the low end and let a pro do it.??

 

[Yamaholic22]

They do have a low oil pressure engine shutdown switch, and it sure doesn't wait 10 seconds to shut it down. It's three seconds. Roll your sled over when doing powder cuts and you will see what I mean. Have done it a few times.

 

[bjowett]

Since you are R&Ring things, I'll recomend having some coatings applied to your main and rod bearings. They are cheap insurance... I use them on any engine I build that has the potential to lose oil pressure.

 

[justinator]

They do have a low oil pressure engine shutdown switch, and it sure doesn't wait 10 seconds to shut it down. It's three seconds. Roll your sled over when doing powder cuts and you will see what I mean. Have done it a few times.

Me too, from what I read on the shutdown it basically senses a sudden drop in oil pressure and kills the fuel delivery. I know if I fall off my sled carving it runs on its side 2-3 seconds tops and then quits. Turn it back over rubber side down and I wait a little bit and fire it up.

 

[TonyVT]

Since you are R&Ring things, I'll recomend having some coatings applied to your main and rod bearings. They are cheap insurance... I use them on any engine I build that has the potential to lose oil pressure.

Thats why I'll let a pro do the fix. Ill do the wrenching...

Should the roller rearing be replaced?

Will I need a complete gasket kit or just a head and maybe a couple others?

What wears on the top of the rod? I see there is no bearing just the piston pin? or might the rod wear?

 

[ReX]

They do have a low oil pressure engine shutdown switch, and it sure doesn't wait 10 seconds to shut it down. It's three seconds. Roll your sled over when doing powder cuts and you will see what I mean. Have done it a few times.

Its good to know it is only 3 seconds, but under heavy throttle that is still probably too long.

I don't even like the idea of idling it for 3 seconds without oil pressure...

 

[TonyVT]

Since you are R&Ring things, I'll recomend having some coatings applied to your main and rod bearings. They are cheap insurance... I use them on any engine I build that has the potential to lose oil pressure.

Thats why I'll let a pro do the fix. Ill do the wrenching...

Should the roller rearing be replaced?

Will I need a complete gasket kit or just a head and maybe a couple others?

What wears on the top of the rod? I see there is no bearing just the piston pin? or might the rod wear?

I have the engine out but not opene up yeat.. If I dont see any damage other than a bearing or 2 can I just replace all bearings and the rings? What about main bearings?
Not sure if I should do this or let someone else? Ive dont some outboards, including a big 4 cyl... Buy I want this right and dont want to do it again....

Who in New England could do this for me? What would it cost?

 

[SledFreak]

Talk to RockerDan, he just did a complete rebuild.

 

[berge75]

If you get a service manual,It'll tell you what you need to know,but you will have to be able to measure with micrometers and calipers,and plastic gauge.

Just wondering how the exhaust doughnuts and y pipes looked when you tore it down?

 

[TonyVT]

Ive got the Yamaha service manual on disk. (pdf) but it's not a step by step its just reference.

If there was a step by step Id feel pretty good about it. But I think theres too many things I could mess up or forget!

 

[stoutner]

Tony, use the service manual and here is a step by step if you haven't seen it yet. http://www.ty4stroke.com/viewtopic.php?t=32636

I just pulled my engine and installed a new piston and one set of rings. It was actually easier than I thought if you pay strict attanetion to the details

I now have 2 rides on my "rebuilt" motor and it runs like brand new.

The tear down is of an RX-1. Motor is the same as Apex with a few subtle differences.

P.S. The head can come off as an assembly. I wouldn't remove the cams if you don't need to. You just have to remove the gears to get the chain off. Each cam has an alignment dot for reassembly. Also, the crank has an alignment dot on the clutch side as well as a magneto alignment dot on the magneto side. Before taking the head off, I would suggest rotating the the cams and motor to TDC with all marks lined up. This will show you how it must be when you reinstall the cam timing chain.

Any questions, PM me at any time.