Topic: Ok! Help me verify I'm putting my motor back together right

[killersoundz]

Ok it's that time for reassembly. CB750K4

First question (a lot more to come)



The bottom left and right studs where the dowels go in are kind of plugged up with debris. are those oil returns or not?

[lucky]

Ok it's that time for reassembly. CB750K4

First question (a lot more to come)



The bottom left and right studs where the dowels go in are kind of plugged up with debris. are those oil returns or not?

Why don't you get a workshop manual??? What if a forum member gives you incorrect info or incomplete info?

Learn to READ A BOOK!!

[killersoundz]

I have the Honda shop manual. Frankly it's on the vague side

[wrenchmuch]

The rectangular slots between 1&2 and between 3&4 just on front of the front studs are the returns.   Lightly coat the 2
corner dowels with grease or anti seize to make future removal easier.

[killersoundz]

Ok thanks. That's what I kind of figured. The dowels are stuck in the bottom of the jugs I don't necessarily want to try to remove them so I'll leave them be.

Next question.

The big orange rings go around bottom of jugs got that, now my Vesrah kit only came with two of the small orange o rings? It seems like I need 4 of those for the oil sends, 2 between the case and jugs and 2 between the jugs and head. If I'm SOL here can I just reuse the 2 I already have between the case and jugs? They seem ok.

What are the 8 bigger black o rings supposed to be for?         My engine is a early K4 before they needed more of the rubber packing on the studs and stuff I do know that.

The kit also only came with 5 of the little black o rings? What are those even for as well?

[brandEn]

Check out my thread
http://forums.sohc4.net/index.php?topic=107040.0

[brandEn]

Those 8 bigger o rings are for the tappet covers. The 2 red ones go between the case and jugs.

[killersoundz]

Those 8 bigger o rings are for the tappet covers. The 2 red ones go between the case and jugs.

Cool, I'll keep an eye on your thread too. I need 2 more o rings the same size as the small orange ones that go on the oil feels between the jugs and the head too though?

[brandEn]

Same part numbers I believe.
#10

O-RING (11X2.5)
91310-426-000 (replaces 91309-035-000)

[brandEn]

#14
O-RING (11X2.5)

91310-426-000 (replaces 91309-035-000)

[killersoundz]

Ok thanks for that. Yeah i'm just keeping my old o rings between the case and jugs and installing the new guys between the jugs and head. The old o rings appear to be slightly larger anyways.

Should I cut away these parts of the base gasket where there is nothing underneath or just leave it go?

[wrenchmuch]

Don't Cut away the gasket . Also don't re use o rings , especially the ones that supply oil to the head . You should be able to find a o ring supplier in your area without
too much trouble . Use on line views like the 2 above posted by branden to find the right sizes then take the list with you . # 15 in the second pic is another important
ring that seals the oil passage between the upper and lower case halves ( i see your cases are already together ) . There are 4 rings that go between the cam tower and the head . One goes around each oil jet and the others go in depressions in the head at the outer end of each tower . These rings are essential in providing oil pressure to the towers . If they leak you'll destroy ( not an exageration ) your towers , cam , and rockers . You've done a lot of work . Don't skimp on a handful of rubber bits that will cost less then a burger , fries , and drink .

[bollingball]

Ok it's that time for reassembly. CB750K4

First question (a lot more to come)



The bottom left and right studs where the dowels go in are kind of plugged up with debris. are those oil returns or not?

Everything should have been spotless before reassembly began.

Answer to first question What difference does it make are you not going to clean it if it one or the other?
 I don't understand for the life of me why you would even consider using old oring.

Ken

[MCRider]

Am I incorrect in saying the wheel on that cam chain tensioner is shot? How's the center wheel, covered by the chain,looking?

[bollingball]

Ok it's that time for reassembly. CB750K4

First question (a lot more to come)



The bottom left and right studs where the dowels go in are kind of plugged up with debris. are those oil returns or not?

Everything should have been spotless before reassembly began.

Answer to first question What difference does it make are you not going to clean it if it one or the other?
 I don't understand for the life of me why you would even consider using old oring.

Ken

I think I figured it out. The picture You are showing must be before final disassemble.

Ken

[killersoundz]

One thing I noticed is that the main o rings for the oil supply between the case and jugs do not even stick up any higher than the gasket, how will they be compressed? The ones between the jugs and the head are the same way (new or not) since the head gasket is pretty thick. What gives?

[killersoundz]

Am I incorrect in saying the wheel on that cam chain tensioner is shot? How's the center wheel, covered by the chain,looking?

They look OK. If I can get 10,000 miles out of this motor with this rebuild I'd be happy.    Keep in mind I bought the entire bike for $150 barn fresh. Well I'm gonna be about $2000 in the hole with it when all said and done but that's irrelevant 

[wrenchmuch]

Do you have calipers ? If so you can measure the rings thickness to confirm that it's 2.5 mm. MCrider brings up the tensioner because the internal rubber pieces in the engine ( primary tensioner , cam tensioner and front guide ) get hard over time. When they do they begin to shed bits of rubber. These generally won't make their way to the main bearings or
head as they would need to pass through the filter but they will go through the scavenge side of the oil pump  , into the tank (scavenge side supplies the transmission too), then through the pumps pressure side ( not good for the pump ). Your cam tensioner already shows signs of this. If you had a new piece to compare to the old one you'd see that rubber is actually quite soft. I understand needing to keep an eye on a budget but if you can find funds to change out these pieces it will help ensure you get 10000 miles out of your work.

[Ernest T]

One thing I noticed is that the main o rings for the oil supply between the case and jugs do not even stick up any higher than the gasket, how will they be compressed? The ones between the jugs and the head are the same way (new or not) since the head gasket is pretty thick. What gives?

The gasket is compressed when you torque the bolts.

[killersoundz]

Do you have calipers ? If so you can measure the rings thickness to confirm that it's 2.5 mm. MCrider brings up the tensioner because the internal rubber pieces in the engine ( primary tensioner , cam tensioner and front guide ) get hard over time. When they do they begin to shed bits of rubber. These generally won't make their way to the main bearings or
head as they would need to pass through the filter but they will go through the scavenge side of the oil pump  , into the tank (scavenge side supplies the transmission too), then through the pumps pressure side ( not good for the pump ). Your cam tensioner already shows signs of this. If you had a new piece to compare to the old one you'd see that rubber is actually quite soft. I understand needing to keep an eye on a budget but if you can find funds to change out these pieces it will help ensure you get 10000 miles out of your work.

I did not know this and they did seem on the hard side. I already started torquing the head down so too late! I appreciate your concern and trust me I want to know everything that could possibly go wrong. This is my first time rebuilding an engine and honestly in the back of my mind I anticipate there being a problem, I wouldn't be surprised nor angry if I get 1000 miles on the motor and it throws a rod. I can get another entire running motor for $150.

[killersoundz]

About those cam tower oilers. I replaced the o rings on them, but why are 1, 4 and 2,3 different? 1 and 4 don't look like they have an opening at all for oil to flow and 2 and 3 do? Seems weird to me...

this is a pic of 4 and 3. notice how 4 cam oiler looks 'closed' and 3 actually has a jet...

[MCRider]

The 1 & 4 as you put it are the "end of the line". No oil past that point. the 2 & 3 are the source, then it loads into the cam towers squirting out of strategically places holes and the cam bearings, stopping at the 1 & 4. By blocking and sealing 1 & 4 you maintain pressure in the towers.

[killersoundz]

The 1 & 4 as you put it are the "end of the line". No oil past that point. the 2 & 3 are the source, then it loads into the cam towers squirting out of strategically places holes and the cam bearings, stopping at the 1 & 4. By blocking and sealing 1 & 4 you maintain pressure in the towers.

Ok I was just curious. For a split second I was like what if I have a defective motor lol but if that was the case it wouldn't have made it to 30,000

[brandEn]

Hey just a tip, make sure and inspect your tappet adjuster screws. The point that contacts the valve tip. Make sure they are not damaged.

[killersoundz]

Hey just a tip, make sure and inspect your tappet adjuster screws. The point that contacts the valve tip. Make sure they are not damaged.

Thanks for the tip! Any extra bit of info up in my noggin' helps