Author Topic: 78 cb 550 4 . what do I look out for? (Read 6119 times)

jeepurz · « **on:** March 18, 2009, 05:02:17 PM »

gettin ready to clean up my motor, it out of the frame, Ive take oil pan off, looks good not a lot of sludgey crap, under 20K miles, what should I check while motors out? what seals , gaskets , orings ect are prone for replacement, & wheres the best place to find them, should I replace pan o-ring? does it pay to smooth cast intakes? Also this is an old pic but arrow points to gunk build up between and above 2&3 Ideas as to whats caused this? This is the first sohc 4 ive done & dont want to get motor back in to find something i missed. .
thanks Jeep.

OldSchool_IsCool · « **Reply #1 on:** March 18, 2009, 06:03:37 PM »

The "sealing rubbers" or "pucks" that cover some head bolts under the head cover are prolly the cause of the gunk you are pointing out. 30-year old gaskets are likely to need replaced. If you take the head off, replace the base gasket too (between cylinder block and crank case). Really isn't a whole lot that goes wrong with these engines. Most parts are available from Honda still. Try www.servicehonda.com or Western Hills Honda in Cincy.

jeepurz · « **Reply #2 on:** March 19, 2009, 10:52:57 AM »

thanks I dug up a micro fish and gezzz Oring O rama! I really was not wanting to pull the head but I reckon it would be smart, theres some oil between jugs and head I thought maybe a retorque might work. But I guess it wouldnt hurt to check out the innards .
Im a little worried about the carb work too, I had to crank and crank to get this started when I bought it and the PO said he'd "fixed the carbs". I hate carbs.

SteveD CB500F · « **Reply #3 on:** March 19, 2009, 11:56:15 AM »

Quote from: jeepurz on March 19, 2009, 10:52:57 AM

the PO said he'd "fixed the carbs"

OMG!

I think most of us have come across a PO like that at some time...

If you've taken the engine out, you've got the bank of carbs sitting there grinning at you. Strip them down and clean them out.

Search on "Carb cleaning" and you'll find a gazillion threads on here!

jeepurz · « **Reply #4 on:** March 19, 2009, 04:07:24 PM »

Quote from: SteveD CB500F on March 19, 2009, 11:56:15 AM

Quote from: jeepurz on March 19, 2009, 10:52:57 AM
the PO said he'd "fixed the carbs"

OMG!

I think most of us have come across a PO like that at some time...

If you've taken the engine out, you've got the bank of carbs sitting there grinning at you. Strip them down and clean them out.

.

Search on "Carb cleaning" and you'll find a gazillion threads on here!

ID guess so, the "fixed the carbs" rates up there with "ran last year" and "needs little to run" . Ive been looking through the carb threads SKEERY as heck but itll workout

jeepurz · « **Reply #5 on:** March 22, 2009, 03:00:15 PM »

im gonna try and keep the questions on this thread , have top end stripped, internals are purty good, I use simple green and scotchbrite on piston crowns but what about valves, Is it ok to use that on those? Im not figureing on dissassembling head.

Also what are the 4 nuts for (pointing in pic)

I ended up with one o ring at tension adj. and two on ea end block oil jets.

Oh and more good news, clutch looked new.

OldSchool_IsCool · « **Reply #6 on:** March 22, 2009, 05:56:36 PM »

I used brake cleaner on the valves while they were still in the head with no ill effects, so Simple Green should be no problem. Anything harsher than Simple Green then you will want to keep it off the rubber valve seals. Shouldn't be a worry unless a valve isn't sealing.

Rest the head level on clean paper towel, spark plugs installed. Let a pool of SG soak over night. In the morning, inspect the paper towel and pools for evidence of any leaks. If a valve DOES leak, then you'll prolly want to disassemble and find out why.

jeepurz · « **Reply #7 on:** March 22, 2009, 06:15:51 PM »

wow never thought of that! I try it tommorrow.

bwaller · « **Reply #8 on:** March 22, 2009, 06:30:06 PM »

Those four nuts locate the lock pins that prevent the rockers shafts from rotating in the valve cover.

jeepurz · « **Reply #9 on:** March 25, 2009, 06:53:16 PM »

thanks for the tips they held overnight, cleaned up great, Im waiting on gasket o'ring set. when I install the cam whats the best way? chain isnt broken. Ive done some xs 650's but there cam is solid gear doesnt unbolt and I put new cam chain in so lineup was fairly simple. with this Ive got to get the cam lined with cam sprocket bolt holes , mount chain and keep timing correct. Or is it easier to break chain and put in link? Is this a solid chain?

OldSchool_IsCool · « **Reply #10 on:** March 25, 2009, 07:32:36 PM »

Jeep,

I just installed a new cam chain in my '77 550. Yes, the chain is "endless" which normally requires you to crack the crank case open to put a new one on. If you are adventurous, you can buy a new chain, break a link out of the old and new chain, use the old chain to draw the new chain around the crank then use a "soft link" for a CB400T to make the chain endless again.

Also, there are really good pictures in the Engine FAQ on how to get the cam sprocket back on and properly timed. I struggled with it until I was directed to the pictures when it suddenly all made sense! The trick for me was to slip the camshaft through the chain FIRST, then thread the sprocket on. Set the crank at TDC for 1.4 and the camshaft notch (extreme right end) to align with the mating surface of the head. With a little wiggling, hook the chain over the sprocket. Use the "Mickey Mouse" ears of the sprocket to help you get the chain on. The sprocket then should be a tooth or two of lining up with the bolt holes. Shift the sprocket teeth under the chain until you have it just right. Put in one bolt, rotate the engine 180 degrees and put in the other bolt. Use a rag to stuff into the cam tunnel so you don't accidentally drop anything into the bottom of the engine.

jeepurz · « **Reply #11 on:** March 25, 2009, 07:42:40 PM »

Quote from: OldSchool_IsCool on March 25, 2009, 07:32:36 PM

Jeep,

I just installed a new cam chain in my '77 550. Yes, the chain is "endless" which normally requires you to crack the crank case open to put a new one on. If you are adventurous, you can buy a new chain, break a link out of the old and new chain, use the old chain to draw the new chain around the crank then use a "soft link" for a CB400T to make the chain endless again.

Also, there are really good pictures in the Engine FAQ on how to get the cam sprocket back on and properly timed. I struggled with it until I was directed to the pictures when it suddenly all made sense! The trick for me was to slip the camshaft through the chain FIRST, then thread the sprocket on. Set the crank at TDC for 1.4 and the camshaft notch (extreme right end) to align with the mating surface of the head. With a little wiggling, hook the chain over the sprocket. Use the "Mickey Mouse" ears of the sprocket to help you get the chain on. The sprocket then should be a tooth or two of lining up with the bolt holes. Shift the sprocket teeth under the chain until you have it just right. Put in one bolt, rotate the engine 180 degrees and put in the other bolt. Use a rag to stuff into the cam tunnel so you don't accidentally drop anything into the bottom of the engine.

thanks ill check that section, I actually think ive got an extra soft link from a 400 A . but im going to try not breakin it first.

jeepurz · « **Reply #12 on:** April 20, 2009, 05:35:05 PM »

got a prob. the one thing I didnt do was check cam chain tensioner , like an idiot, ive got the head on and need a little slack , Using the a thread on this cam install was great help, but didnt prevent my stupidity.
OK how does the cam chain tensioner work? I cannot get the screw to turn .ive loosened the set nut , im so close to getting sprocket over lip on cam, I do not want to pry. Also if ive got a tensioner problem can i remove it without unbolting the head, heck I cant remember when I took it apart. thanks in advance.

OldSchool_IsCool · « **Reply #13 on:** April 20, 2009, 05:39:54 PM »

OK, so you are trying to relax the tensioner to give you a little more slack? Is that what you are trying?

Loosen the lock nut then either turn the screw to back off the spring-loaded tensioner or work a tool down there to push it in. Once it is retracted, lock down the nut again.

Yes, I think you can get the tensioner out without removing the head, but you will need to get the chain, sprocket and possibly cam shaft out of the way.

jeepurz · « **Reply #14 on:** April 20, 2009, 05:46:36 PM »

its all still loose, the screw on the tensioner wont budge, its no prob to pop the cam back out. I shoulda studied the tensioner before I put it back in.

OldSchool_IsCool · « **Reply #15 on:** April 20, 2009, 05:50:03 PM »

Then definitly pop it out. You'll notice that the end of the screw is a pinion gear that engages a rack on the tensioner. If the tensioner is working properly, turning the screw should cause the rack & pinion to retract or extend the tensioner blade.

jeepurz · « **Reply #16 on:** April 20, 2009, 05:54:24 PM »

Quote from: OldSchool_IsCool on April 20, 2009, 05:50:03 PM

Then definitly pop it out. You'll notice that the end of the screw is a pinion gear that engages a rack on the tensioner. If the tensioner is working properly, turning the screw should cause the rack & pinion to retract or extend the tensioner blade.

whew , the feeling of being an idiot has subsided. thanks a lot!!!! confidence restored! I just knew id have to take the top end back off. Ill probably be back in a week or so.

jeepurz · « **Reply #17 on:** April 23, 2009, 05:50:13 PM »

ok hopefully this is the last timing question,
, the prob ive got is this sprocket could be 180deg off right?

I can find no info in manual about marks on this sprocket although there are punch marks. I mounted it according so some pics of other 550's from what I could see, Its Not bolted down for sure yet but id like an opinion. thanks.

hash mark

T mark

(this pic is copied from some info I found) Im hoping this is correct.

book says

OldSchool_IsCool · « **Reply #18 on:** April 23, 2009, 06:10:47 PM »

As long as your T1.4 mark lines up with the case pointer, the cam notch is horizontal (aligned with the head's mating surface), and you can get a screw through the sprocket into it's fixing hole you are golden! Yes, the sprocket can be 180 degrees off. In fact, after you tighten down the first sprocket screw, rotate your crant exactly 360 degrees (clockwise, until the T1.4 again alines with the case pointer). You'll notice that the cam shaft notch is horizontal again, but on the oter side and the 2nd bolt hole is exposed on the sprocket.

One turn of the crank ia a HALF turn of the cam shaft.

jeepurz · « **Reply #19 on:** April 24, 2009, 10:30:51 AM »

thanks again, I think Im good to go. the manuals are really sketchy on this deal.

bryanj · « **Reply #20 on:** April 24, 2009, 10:48:28 AM »

In fact the Honda manual is pretty good for this one but as in all Honda manuals it is written for a dealers workshop and assumes basic knowledge

jeepurz · « **Reply #21 on:** August 23, 2009, 05:51:43 AM »

got another question, been purty much off mowing , fishing, working, ect and im finally jumpin back in this.

I have a complete gasket set for this, these O Rings are what ive got left, I removed the O Rings from the old intakes , as shown in pics there smushed beyond recogniton , the O Rings I have left look small? Im wondering if there right, And there were 5 of these where I need 4, I installed the new ones on valve adj caps and am only doing top end.

Also Im redoing the carbs and do most gasket sets contain O rings for carbs? are those the greenish grey ones?? (sorry color blind) .

OldSchool_IsCool · « **Reply #22 on:** August 23, 2009, 06:21:16 AM »

Your kit may have been packed with an extra or maybe you missed one of the tappet covers. The intake and tappet cover O-rings are the same.

jeepurz · « **Reply #23 on:** August 23, 2009, 06:42:05 AM »

Quote from: OldSchool_IsCool on August 23, 2009, 06:21:16 AM

Your kit may have been packed with an extra or maybe you missed one of the tappet covers. The intake and tappet cover O-rings are the same.

thanks for the info! ill check my caps n see if i missed one.

jeepurz · « **Reply #24 on:** August 24, 2009, 03:47:25 PM »

im using motorcycle classics, bike bandit cafe build for referance on the carbs, there 73 yr mines 78 so theres some dif. This bike ran before strippin it but was A PIA to start, & didnt idle good, again the PO "FIXED carbs".
a couple questions.
looks as if ive got something missing on carb where finger pointing.

I must remove this screw of 4 total to separate correct?

the brass Ive got my finger on isnt slotted , do I use plyers to remove? it is threaded?

last is there as linke that shows a blowup of these carbs? thanks in advance

jeepurz · « **Reply #25 on:** August 24, 2009, 03:56:46 PM »

better pic of missin part.

OldSchool_IsCool · « **Reply #26 on:** August 24, 2009, 04:07:15 PM »

No parts are missing. The #2 carb has a non-adjustable slide. Use #2 as your reference carb and balance the other three to it.

Why do you want to pull your carb bank apart? Unless you have leaks in the fuel gallery tubes between the carbs, clean them while they are together.

The stubby brass jet is the idle jet. On later carbs, they are pressed in. You can pull them out with pliers. Just be careful you don't crush them.

jeepurz · « **Reply #27 on:** August 24, 2009, 04:20:26 PM »

Quote from: OldSchool_IsCool on August 24, 2009, 04:07:15 PM

No parts are missing. The #2 carb has a non-adjustable slide. Use #2 as your reference carb and balance the other three to it.

Why do you want to pull your carb bank apart? Unless you have leaks in the fuel gallery tubes between the carbs, clean them while they are together.

The stubby brass jet is the idle jet. On later carbs, they are pressed in. You can pull them out with pliers. Just be careful you don't crush them.

mainly wanted to pull em apart to clean the bodies and polish em up a little, if theres a better way im in. this is Skeerin the heck outa me and im fearless.

jeepurz · « **Reply #28 on:** September 12, 2009, 11:20:50 AM »

welp thought id post up a progress report, thanks to everyone hePPin out.
Still gotta get carbs back on back together , get tires , and wiring .

jeepurz · « **Reply #29 on:** December 10, 2009, 06:27:01 PM »

little more update wise , hahanda (think he's a member here) and I crossed paths on another board and he redid the carbs cause I hate carbs. that said, wiring brakes and some misc is all thats left. Oh the seat , a guy from another boards stitchn that up .

kranta · « **Reply #30 on:** June 18, 2014, 12:05:12 PM »

about the timing how did you put the timing because i am thinking the timing so did you put the timing so that the you turn the crank to the tdc 1.4 and then put chain on the sprocket and then you put the sprocket on camshaft and then you turn the camshaft so the centre of cutout notch is aligned to the cylinder head flange surface and then you look how much the sprocket is off the bolt holes and then you take the sprocket back and change the sprockets teeths until you think its right and then you put sprocket back and if camshaft is turn off the timing marks place then you turn the cam right position and then you look how much the sprocket is off the bolt holes and if it is then you do again what i was sayed or how you did it?

?
sorry, bad english!

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Author Topic: 78 cb 550 4 . what do I look out for? (Read 6119 times)