Topic: cb400f - before I assemble cases... CRAP! Must I split the cases again?!?

[lohebohi]

I just wanted to double check with you guys before I reassemble the cases.

1. The ends of both transmission racks have one pin that they end bearing sits on.
2. I will put the crank in the case and bolt the rod to the crank.
3. The cam chain and big chain will be around the crankshaft.
4. I will use assemble lube on the crank bearings and rod big end caps.
5. I count 4 rubber oil seals, one on each transmission, and one on each side of the crankshaft.
6. The tranny oil seal in the rear of the pic has a rubber locating pin that will go in it's hole.
7. I have 2 locating dowels at the bottom left and right (in the pic) of the case.
8. There is a 52-mm bearing set ring (half-piston ring type thing) in each groove for each transmission rack.

What is the torque setting connecting rod bolt?  <<Torque for big end nuts is 14.5 to 15.9 lb ft.>>

Does anyone see anything I am missing?

The machinist that reseated my valves and replaced my valve seals told me to use engine oil and not assembly lube because I am using old bearings and assembly lube has a slight grit to it.  But another friend of mine who works in a extreme high performance engine shop disasgreed and told me to use assembly lube.  Does anyone have any thoughts on the matter.  I did have the camshaft polished. 

Should I get the crankshaft polished?  Or say screw it, summer is fast approaching.

[bryanj]

The "Normal" way to build is to have the rods bolted to the crank then fit the pistons afterwards.
As to lube:-
Oil if its will be run soon
lube if its going to stand a while

[lohebohi]

What about the torque for the big end of the rods?  I could not find that in the manual. <<Torque for big end nuts is 14.5 to 15.9 lb ft.>>

[Tim2005]

Torque for big end nuts is 14.5 to 15.9 lb ft.

Your list misses one thing: after installing the crankshaft you need to refit the camchain tensioner mechanism (the horseshoe part) before you join the cases.

Nice clean motor by the way.

[Sweep]

I'd get the crankshaft polished and lightened if you have the funds unless you're really in a hurry to get done.  My take is that our time is valuable and who knows when you'll get to have the motor completely apart like this, it's now or never.  I have mine at APE and in line to be done now along with my cyl head for reworking and cylinders for boring.

[lohebohi]

Thanks for the complement on the cleanness.  You should see the bolts.  I replated all of them with the Eastwood home palting kit.  It works awesome.  I don't know how well the plating will hold up over time, but they all look brand new as of now.

Good call on the tensioner.  I might have forgotten.  I noticed when I took the tensioner apart, it seems like it was stuck becuase it popped at one point.  Should I use grease in there?  I would just use oil, but that oil would be trapped and would eventually decompose.

Someone mentioned APE Raceparts (located at Willow Springs Raceway), so I looked them up and here is their link, http://www.aperaceparts.com/
keywords: machine shop, head work, engine, race, parts

[Tim2005]

I was wondering about trying one of those kits sometime myself, Frost's do one which I've seen recommended too, though it comes to around £130 so I've been holding off. Worth it?

The tensioner should not need greasing - just a little oil ought to be fine. However, if yours is sticking then it is almost certainly suffering the very common problem that some grooves have been worn into it by the (slack) camchain and they are making it sticky. Get a tiny triangular file and clean up the edges of those grooves where the horseshoe meets the bracket, until it moves freely and smoothly. If not, you'll never get the chain to adjust! Hopefully it isn't worn too badly as the part is no longer available from Honda.

Oh, remember to fit the tensioner pushrod and springs before fitting the tension mechanism and joining the cases.

[lohebohi]

I was talking about the tensioner pushrod not sliding smoothly.  I wrapped some 600-grit sandpaper around a round P2 screwdriver and moved it in and out in a sexing motion.  The hole looked like it had fine threads before and now it is smooth and the pushrod moves in and out smoothly.  I used a can of compressed air to clear out the hole of any residual shavings.

As for the horseshoe tensioner arm, it does have those grooves you mentioned.  I have attached a photo for anyone who might not have understood (I did not at first).   I bought a triangular file from Home Depot for $4 and fixed that horseshoe tensioner arm.  It took a little time but eventually I got it so that it rotates on it's pivot without any resistance at all.

I have done everything on my list above. 

I pressed the tensioner pushrod as far as I could push it, then tightened the bolt that presses against the pushrod.  I figured this would make it easier to install the tensioner later.

A note about installing the seals.  I put a little assembly lube around the inner surface for lubrication and gently slid them over their respective shafts.  You have to be very careful to slide them on perfectly straight.  I messed up two of them by not pushing them on perfectly straight.  The metal spiral sping inside the seals came out and they were a little tricky to get back in place.  That was when I decided to use a little lube and put them on very carefully.

[lohebohi]

So we bolted it together and everything went smoothly.  I recommend putting the Threebond 1104 gasket material on the bottom half of the case.  I put it on the top and there are some places where the bottom does not cover the top as shown in the third picture.

There is a big bolt in the third picture that is not shiny.  Does anyone know what that bolt does?  Can I remove and reinstall it?

[bryanj]

Thats an oil gallery plug cap and made of alloy. Just a thought but did you locktight the bolts that hold the horseshoe to the case? I have seen these fall out before now!

[lohebohi]

How do I get the Primary Driven Sprocket in?!?

I cannot get the gear inside the chain.  I am starting to think I am going to have to split the damn cases again.  I know I removed the gear before I was able to split the cases, but now I cannot do it in reverse.

It is number 138 in the pic from the parts manual.  I also have no idea how I am going to be able get number 139 to slide in with all the rubber pieces (140).  Also right now I have a piece of paper towel in 182 to keep 184 and 270 from falling out, but I am going to have to pull that paper towel out and somehow get 181 to slide in without popping 184 and 270 out. 

Honestly I would not care that much about splitting the cases at this point because I am so pissed off, but I used Threebond 1104 and it will be an incredible pain in the ass to get off.

[ttr400]

Well the bad news is you are going to have to split the cases again.

When apart the procedure is as follows, first assemble the complete primary driven sprocket/starter clutch hub (137) with 265 and 181.
Make sure you have circlip 335 and bearing 351 installed in the lower case half, oil pump side. also install the inner circlip 335 on the clutch side.
Install the complete hub assembly to the primary chain and let it rest on motor. Do not install the primary shaft.
Fit the lower case, make sure it seats correctly on the dowels etc.
Install the primary shaft from the oil pump side, as the shaft goes through the hub and gear install the spacer 134, now you can install the other bearing 351 and circlip 335. install all bolts etc and torque crank bolts.
Last job is fit the secondary drive gear, lock washer and bolt.

Kevin

[lohebohi]

We split the cases and when we were trying to remove the connectiong rods, we spun 2 bolts and had to get connecting rod bolts off with a cutoff wheel.

I am going to disassemble the parts engine and get two rods out of there.  I know someone said the standard operating procedure is to remove the pistons from the connecting rod, but I have no idea where to buy the tool for removing the piston pins.  Aren't they pressed in?

[ttr400]

Why were you removing the rods??? I thought you just had to install the primary driven sprocket.

Kevin

[lohebohi]

I had to take the cases all the way apart to remove the Threebond 1004 adhesive.  I have a parts engine that I took the crank and rods from.  I figured out how to take off the pistons.  The pins slide right out. 

[lohebohi]

Does anyone know why you are supposed to put on the connecting rods with the bearing detent facing forward (exhaust side)?

I think I might have gotten this backwards, since I put the rods on the crank while it was on the table.  I might have been thinking upside down.  This time we have the engine in the bike and the pistons and cylinders installed. 

Of course the worst possible scenario is that it is all in my head and I split the cases again only to find I had it correct all along.

On the bright side, I am getting pretty good at taking everything apart.

[lohebohi]

This picture confirms it.

The connecting rods are on backwards.

It really sucks to keep going backwards, but I am more concerned with the fact that last time I tried to remove connecting rods, two of the connecting rod bolts spun.

Is there someone that can tell me this will be okay?  The connecting rods are not symetrical.  The oil hole on the top is offset to one side, and the hole on the underside of the piston pin location is offset to the other side.

This weekend is the begining of warm season here in Maryland and we still have a ways to go without going back to the starting point again.  And plus we are dead in the water if those poorly designed connecting rod bolts spin again.

[Tim2005]

I doubt anyone's going to know for sure if that will matter. Personally, I'd think there's a very good chance you'll get away with it, but there's no way to know for 100% certain.  What are you planning on using the bike for? 400f rods (when correctly installed) are not a weak point in normal use, only getting a bit unreliable with big bores and 11000+ rpm.

[lohebohi]

It will be used for normal everyday riding.  Which way does the crankshaft rotate (same as the tires or opposite)?  I wonder if the tabs are supposed to be towards the front because of the crankshaft force vector at point of combustion?  Or is it more than that (based on the position of the holes in the little end of the rod)?  Or does oil get slung off the crankshaft on one side towards that hole on the bottom side of the little end of the rod?

The manual specifically says to do it one way.

[Bodi]

Hopefully I'm not the only puzzled one. Why did you touch the rods? The whole crank with rods, pistons, and everything will lift out of the top case. Anyway, looks like you're learning a lot. I learned the hard way to check everything twice - I forgot to crimp the lockwasher on the bolt that captures the starter gear (your first pictures were a reminder) and it came loose about 30 miles from home on my first long ride with the reassembled motor.

[lohebohi]

I understand that taking the rods off is not something that most people do but I am confused as to why anyone would be puzzled by removing the rods.

If I was doing a more thorough rebuild (what I will do next time) I would replace the rod bearings.  Through my issues I have seen the inside of two sets of rods and both sets could have used new bearings.  Just because most people do not look at the bearing surface does not mean they are in good shape.

Not only that, disassembling the rods allowed me to put assembly lube on those bearing surfaces.  And if I were being more thorough, I would have machined the mating surface and bored the big ends of the rods to round again.  But I am not being that thorough this time.

Oil comes from the crankshaft into the bearing on the big end of the rods, where it then goes through a channel on both sides of the big end of the rods.  But I would probably just buy Carillo rods for the next rebuild because of the design deficiency.  The rods bolt heads are almost round to begin with.

Also, you can't pull of the crank unless you remove the pistons or the rod/piston assembly.