Topic: It has begun!!! Another 550 top end rebuild

[dave500]

good job!take your time,if you need to stop and pause for a while and double check as you go,plenty of oil on those stems and guides?

[Adam_F]

good job!take your time,if you need to stop and pause for a while and double check as you go,plenty of oil on those stems and guides?

Yep.  Oiled 'em up good while reassembling.  I read an old comment of yours about tapping the stems with a hammer to see if anything moves around.  I'm assuming you tap the end of the stem a couple times?

Thanks Dave!

[dave500]

yep place a thick rag over it and just a couple of short sharp raps on the stem only,if the keepers gonna let go itll do it now,dont strike the retainer though!

[Adam_F]

yep place a thick rag over it and just a couple of short sharp raps on the stem only,if the keepers gonna let go itll do it now,dont strike the retainer though!

Great!  Thanks!  I've done some research, but any tips for a proper leak down test?

[dave500]

try filling the inlet and exhausts with kerosene and let them sit a few minutes one side at a time.

[Adam_F]

Did a leak down test today with some kerosene (as recommended by Dave).  Didn't leak a drop, which was a huge relief.  Then I went ahead and installed my new piston rings.  Made sure to space them out like the manual says, but I'm guessing I'll need to double check 'em as I squeeze them to install the cylinders.



Out with the old carb boots



And in with the new



Looks like I'm totally ready to start putting this bad boy back together!  Gonna probably need an extra set of hands as I don't plan on buying a ring compressor.  Just one quick question for you guys...  I bought honda gaskets.  The base gasket has a matte side and a slightly more satin side.  Does it matter which side faces up (towards the jugs)?

Thanks!

[goldarrow]

I find it easier to install carbs, then install the boots.

[riverfever]

Just saw this and read through it. Very informative. Thanks for documenting the process. I have a 500 that I'm working on and I know I will have to tear into it and do similar repairs soon.

[Adam_F]

I find it easier to install carbs, then install the boots.

Oh yeah? Interesting. Never done that way. If I have a hard time I'll give it a whirl.

[Adam_F]

Just saw this and read through it. Very informative. Thanks for documenting the process. I have a 500 that I'm working on and I know I will have to tear into it and do similar repairs soon.

Couldn't do it without the info on this forum and help from its awesome members!

[dave500]

don't worry too much if the staggered ring gaps move a little it aint critical,just go slow slipping the jugs over them,i do the inside pair first,a piece of pine cut to size is handy placed under the piston skirts to stop the whole set up from moving as your installing,i do them with them at bdc.

[Adam_F]

don't worry too much if the staggered ring gaps move a little it aint critical,just go slow slipping the jugs over them,i do the inside pair first,a piece of pine cut to size is handy placed under the piston skirts to stop the whole set up from moving as your installing,i do them with them at bdc.

Thanks Dave. Total noob question, but does it matter which side of the base gasket faces up? Looks like each side had a slightly different t surface finish. Can't imagine it makes a difference but I just wanted to make sure.

[iron_worker]

As long as all the bolt holes and oil ports line up then you should be good to go.

Be prepared for a bit of a fight with getting the pistons back in the jugs ... definitely having a second set of hands helps. 2 strips of wood to support underneath of the 2/3 pistons (either side of the rod) really helps. I didn't use ring compressors just used popsicle sticks to compress the rings as they come up against the bottom of the sleeves. Don't use any metal tools here because you'll score everything all to hell. Some people use hose clamps but I don't like the idea of that.

Go slow and make sure the cylinders are going down straight and evenly. I found that when trying to get the 1/4 pistons in they would tend to want to get cock-eyed in the bore (tilting at the wrist pin). Knocking on the tops of the pistons ... gently! ... with the wooden handle of a hammer seemed to help knock them straight.

Oh ya, put some engine oil in the cylinders, on the piston skirts, and a dab on the rings. Some say not to use oil for break in purposes but that makes it REALLY hard to get new rings into fresh bores.... ask me how I know .... I ended up snagging an oil ring, bending it over, and gouging my cylinder sleeve when I got rammy and tried to force it.  So like I said before: GO SLOW! You shouldn't need more force than gently tapping down on the cylinders with the palm of your hands.

IW

[Adam_F]

As long as all the bolt holes and oil ports line up then you should be good to go.

Be prepared for a bit of a fight with getting the pistons back in the jugs ... definitely having a second set of hands helps. 2 strips of wood to support underneath of the 2/3 pistons (either side of the rod) really helps. I didn't use ring compressors just used popsicle sticks to compress the rings as they come up against the bottom of the sleeves. Don't use any metal tools here because you'll score everything all to hell. Some people use hose clamps but I don't like the idea of that.

Go slow and make sure the cylinders are going down straight and evenly. I found that when trying to get the 1/4 pistons in they would tend to want to get cock-eyed in the bore (tilting at the wrist pin). Knocking on the tops of the pistons ... gently! ... with the wooden handle of a hammer seemed to help knock them straight.

Oh ya, put some engine oil in the cylinders, on the piston skirts, and a dab on the rings. Some say not to use oil for break in purposes but that makes it REALLY hard to get new rings into fresh bores.... ask me how I know .... I ended up snagging an oil ring, bending it over, and gouging my cylinder sleeve when I got rammy and tried to force it.  So like I said before: GO SLOW! You shouldn't need more force than gently tapping down on the cylinders with the palm of your hands.

IW

Thanks SO much!  Have a buddy coming over to help, so I'll cut some strips of pine to make the process a bit easier (hopefully).  Will take pics and report back this evening!

[dave500]

if your up for it do a practise run without the rings?polishing that lead in chamfer makes it easier aswell,some look quite rough.

[Adam_F]

A friend of mine came over today after work to lend a hand.  He even brought brought beer....  I then realized I should've had beer with me throughout this entire process!  Rookie mistake number 1,....  Though actually probably more like #200 for me when you look at it chronologically.  Anyways, tried to use pieces of pine to level pistons #2 and 3, but they just felt like they were in the way.  We managed to get those two in relatively easily.  Turned the crank a bit to get 1 and 4 up a bit more.  They were definitely a bit more of a challenge.  They'd go in, then quickly want to bend at the piston rod and get stuck.  With gentle taps from the wooden handle of a mallet, they eventually went in and would move easily in their sleeves.  No way in hell I could've done it without an extra set of hands.



Getting the cam chain tensioner in properly was definitely a bit more tricky.  I'd read that its really easy to miss the little slot at the bottom where it sits in... and sure enough, it was difficult.  Since a busted tensioner was the primary inspiration for this, I definitely wanted to make extra sure it was dialed in proper.  So we dropped the sump pan to get a better view.  After about 10 tries, we finally figured it out and got it to seat



The fact that you can't see it in the picture above is a good thing.  Also took a look at my oil screen while in there and it looked pretty darn clean to me.



Cam chain guide was a piece of cake.



Then we installed the head (along with gasket, dowels and orings) and torqued it down to 15lbs in the correct order.  This is where I really wish I'd gone for a quality tool.  The torque wrench I got from Harbor Freight works... but the clicking sound it makes when you reach proper pressure was totally inconsistent.  Sometimes it was really obvious and others it was barely audible.  Definitely gonna retorque tomorrow and make sure its all good.  Then I'll throw on the pucks with a bit of gasket sealer to keep them in place.



So I do have a question about timing.  I understand that the cam shaft goes in before installing the sprocket.  Seems like it would make sense to line everything up at this point (cam shaft in appropriate spot.  At this point I would line up the timing to the T 1 4 mark THEN put the chain over the sprocket (rather than putting the chain over the sprocket first, then lining up timing)  Correct me if I'm wrong about this please! But when I turn the crank, my chain moves, so if it was on the sprocket, the sprocket would then turn and potentially not line up with the cam shaft. 

Through everything I've read and researched, this is the part that's hard for me to visualize.  And its a pretty important one    Any help is greatly appreciated as always!  Either way, felt good to get stuff done!

Thanks!

[Adam_F]

Well, found this thread and it makes sense.  What seems tricky is getting the sprocket onto the cam after installing the chain.  In the sense that when attaching the two bolts.... on appears as though it would be on the bottom and really hard to reach.  Everything I've read says it makes sense when you do it and it only goes together one way... so I'll trust in that! 

http://forums.sohc4.net/index.php?topic=51740.0

[iron_worker]

To install the cam, first make sure the chain is grabbing the sprocket below (shouldn't be able to pull the chain around without pulling the crank with it), then start threading the (correct ... you have to thread it through such that you're pushing the flange that will bolt onto the sprocket towards sprocket... only goes in 1 way obviously) end of the cam through the chain and then through the sprocket. Basically, you'll keep the chain and sprocket at the center of the engine and feed the cam in from the side. It will take some fiddling around to get the chain and sprocket over each cam lobe. Once you have the cam fished through such that the sprocket and chain are over the center of the portion of the cam you can then set the cam down into it's bearing journals.

Now, check that you have the crank turned such that your index mark (at your points) is lined up with #1/4 TDC. There is also a notch on the end of the cam shaft that needs to face up (on the 750 there is anyway and I believe the 550 is the same). This will ensure that your cam and crank are in time. Now the trick is to put the chain onto the sprocket before it is pushed up against the flange... this way you can use the notches in the sprocket bore to drop it down slightly on the cam shaft and give a bit more clearance to pull the chain on. Then once the chain is over the sprocket you push them both up onto the flange and line up the bolt holes. Put the top bolt in first then spin the motor over by the crank one revolution (1/2 a cam revolution) and get the top bolt in. Now check that your engine is still in time. Spin the motor around until you're on the #1/4 TDC mark again and see if the cam notch still points directly up. If it's pointing directly down THAT's OK... just spin the engine over one more full 360 at the crank. If it looks like the notch is not quite lined up (off by 10 degrees or so) then you're probably off a tooth on the sprocket and you'll have to pull the sprocket bolts out again and try to get the chain/sprocket lined up 1 tooth ahead or back to get it aligned properly.

Once you have checked and double checked that your cam is in time (#1/4 TDC should have the cam shaft notch point up every other revolution) torque the sprocket bolts to manual spec! (You'll have to spin it around again to get access to the bottom one.

Don't worry about spinning the engine over at this point because your rockers are not in at this point so no valves will be open and thus no contact can be made to the pistons.

One point to note is that you have to thread the cam through the sprocket first and then the chain. Otherwise, once get it to to the middle the chain will bind since it will be forced over by the sprocket. The chain must be centered over the tunnel... I learned that one the hard way. lol

IW

[Adam_F]

To install the cam, first make sure the chain is grabbing the sprocket below (shouldn't be able to pull the chain around without pulling the crank with it), then start threading the (correct ... you have to thread it through such that you're pushing the flange that will bolt onto the sprocket towards sprocket... only goes in 1 way obviously) end of the cam through the chain and then through the sprocket. Basically, you'll keep the chain and sprocket at the center of the engine and feed the cam in from the side. It will take some fiddling around to get the chain and sprocket over each cam lobe. Once you have the cam fished through such that the sprocket and chain are over the center of the portion of the cam you can then set the cam down into it's bearing journals.

Now, check that you have the crank turned such that your index mark (at your points) is lined up with #1/4 TDC. There is also a notch on the end of the cam shaft that needs to face up (on the 750 there is anyway and I believe the 550 is the same). This will ensure that your cam and crank are in time. Now the trick is to put the chain onto the sprocket before it is pushed up against the flange... this way you can use the notches in the sprocket bore to drop it down slightly on the cam shaft and give a bit more clearance to pull the chain on. Then once the chain is over the sprocket you push them both up onto the flange and line up the bolt holes. Put the top bolt in first then spin the motor over by the crank one revolution (1/2 a cam revolution) and get the top bolt in. Now check that your engine is still in time. Spin the motor around until you're on the #1/4 TDC mark again and see if the cam notch still points directly up. If it's pointing directly down THAT's OK... just spin the engine over one more full 360 at the crank. If it looks like the notch is not quite lined up (off by 10 degrees or so) then you're probably off a tooth on the sprocket and you'll have to pull the sprocket bolts out again and try to get the chain/sprocket lined up 1 tooth ahead or back to get it aligned properly.

Once you have checked and double checked that your cam is in time (#1/4 TDC should have the cam shaft notch point up every other revolution) torque the sprocket bolts to manual spec! (You'll have to spin it around again to get access to the bottom one.

Don't worry about spinning the engine over at this point because your rockers are not in at this point so no valves will be open and thus no contact can be made to the pistons.

One point to note is that you have to thread the cam through the sprocket first and then the chain. Otherwise, once get it to to the middle the chain will bind since it will be forced over by the sprocket. The chain must be centered over the tunnel... I learned that one the hard way. lol

IW

Wow!  Can't thank you enough for all this info! Most detailed description I've found. I know there is a small difference in the orientation of the cam notch. On the 550 it faces straight ahead or horizontally. But you've definitely made this process crystal clear to me! I was especially curious hot to check for proper timing. So HUUUUGE thank you once again kind sir!

[dave500]

yep 500/550 the notch is horizontaly set to the gasket surface,the book says forwards,it can in fact be rearwards aswell,once its installed rotate by hand and recheck your marks,the 1/4 T mark should be at the index mark on the case and the cam end notch horizontal.

[Adam_F]

Just like I read everywhere, installing the cam, sprocket and chain made a lot more sense when I actually went to do it.  Took a couple tries to get it on the right sprocket.  It was amazing how much easier it was to take the chain on and off the sprocket with a functioning tensioner.  I had a hell of a time getting the chain off in the tear down.  Eventually got it right and turned the crank a bunch of times to make sure it wasn't off a sprocket.

T 1.4


Cam notch level w gasket surface


Success


Then installed the intakes from the carbs


Backed out the tappets and rubber banded them up.


Couldn't get the cylinder cover gasket to stay in while I was trying to install it, so I called it a day.  I have grease around but not sure what would be good to put in there to keep it in that wont have negative effects....?

Bought a set of SS allen bolts.  Only silly thing is that they aren't marked by part number.  Makes it really hard to know what goes where.  Guess I'll have to bust out the parts manual and a micrometer  



I saved the bolts that go under the breather cover, but now I can only seem to find 3 of the 4... even thought I bagged and labeled everything...  Sure hope those are included in the set above...  Don't see why they wouldn't be.  Also have a bunch of 6mm copper crush washers. 

I need to work in my studio tomorrow all day to finish up a big commission, but I'm really hoping to finish with the engine, install the carbs, hang the exhaust, oil 'er up and see how she runs!!!  Then ideally do a carb vacuum synch as well.  Ambitious?  Maybe 

[Adam_F]

is it just me, or does anyone else find this confusing   

[dave500]

good job on the cam timing,now rotate the crank 360 degrees back to the 1/4 t mark,where is the notch now?the parts lists shows what length bolt goes where.

[Adam_F]

good job on the cam timing,now rotate the crank 360 degrees back to the 1/4 t mark,where is the notch now?the parts lists shows what length bolt goes where.

Yep. Cranked it around a few times just to be safe. I have the parts manual but it's really hard to see what goes where from the pic I posted above. At least for me. I'll figure it out eventually.

[dave500]

ok,rotating the crank 360 or one revolution back to the 1/4 t mark will have the cam notch to the rear?itll take 720 or two revolutions to bring it back to the front,you can install the notch to the front or the rear.