Great vid as always! Thanks for sharing your wealth of knowledge. Your approach to problem solving is very helpful because I often struggle to know where to start and what process to follow. Keep up the good work
You see the best thing to do Jim is drop the Part 1 from the title and people will stop bugging you for Part 2 🤣🤣🤣 I love your channel, and appreciate the technical advice you give. Merry Christmas mate and Happy New Year. Rich
Merry Christmas and Happy New Year back to you dude, Thanks for the comments! You're probably spot on with using Part 1 in the title. I've set everyone's expectations. There will be a part 2 Jan I promise :)
Yes it would because you are switching off power to the ignition coils in most cases. However with an awful lot of bikes this also stops the starter from working which is annoying :) Very good point though.
do yourself a favor and take out all plugs when doing compression check. The engine will give you a more accurate reading across all cylinders. Also I would have squirted some oil into the combustion chambers after each initial test to see if the readings change. You would have known if the bores/pistons or valves are at fault!
The difference with plugs in of out is so small its basically insignificant, and would make not difference to the diagnosis. Obviously if it appears to crank slowly then its a problem but that wasn't the case. As I said in the Video if you need more of an accurate diagnosis in terms of how you are losing the compression without stripping the engine you should be doing a cylinder leak down test. The oil in the cylinder trick is a bit of a hit or miss thing and wouldn't tell you if it was Inlet or exhaust valves.
Don't you have to remove the engine from the frame to take the head off? Also, you tested compression cold and with the motor not been running for a long time - it might be better after running , getting all the rings loosened up and lubricated, what do you think?
Hi Paul, As you can see the head and barrels are easily removed with the engine still in the frame. With some bikes this isn't possible because the frame gets in the way. And with others it's possible but you're better off just taking the engine out because access is so poor and removing the engine is the quickest option. You are spot on that a compression test whenever possible should be done on an engine as close to operating temp as you can get it. Generally speaking you would only see a difference of a few psi between hot and cold. Sometimes the hot readings are lower. The way to think about it is if you had an engine in perfect condition would you expect to see readings under the min specification if you did a cold test!
Would there be no value in a shot of oil in the bores, and then a re-test to rule out piston rings ? Even for information's sake. In other words, what are the chances of it being bad rings in all four cylinders? Subscribed by the way, and thanks.
Thats not an amateur question at all, it's a really intelligent one! I'm surprised you are the first person to ask it! You'll notice in the timelapse at the end that I remove the end cover for the crank and both valve adjusting caps on number 4 cylinder. I get that cylinder at TDC on compression and just feel for some clearance by hand. Given that all the Cylinders are down on compression by about the same amount its it's highly unlikely to be tight valve clearances. However you are spot on, it's something that needs looking at before stripping. I should probably have mentioned it but didn't. I'll talk about it in part 2!
So you took a motor that had been sitting, started it once then ran compression and pulled the top end. Why not start up, warm it up, run it hard, set the valves and check the compression?
The engine had been run a couple of months ago by the previous owner attempting to fix it. No amount of running "hard" or otherwise is going to get this engine anywhere near the min compression spec. When doing a compression test you just need to make sure you have a clearance. A few thou out either way won't make any different to the readings, so long as the valve is able to close completely.
@@SuperbikeSurgeryTV The problem is that if the bike has been sitting, carbon and other crap can come loose and stick to the valves. Running them helps to ensure that the crap is blown out. Have seem compression go up on a motor that has set after a good run more than once.
@@maxheadflow "Carbon and other crap can just come loose"?? What other crap? And have you ever tried cleaning carbon off the head of a valve? There is no way it's just happening to fall off and get stuck on the valve seat on EVERY cylinder after standing for a couple of months. I've seen engines that have stood for years and years have problems with rusty valve seats but this is only on the valves that happen to be open when the engine was last turning.
@@SuperbikeSurgeryTV From sitting, yes. Generally from the combustion chamber. If the bike hasn't been run hard carbon can flake loose and stick the valve faces. I've cleaned lots of valves. I've seen relatively new bikes (back when these were new) have this issues.
@@maxheadflow 30 years at this and I've never come across it?? However the point I was making was you wouldn't get consistently low compression across all the cylinders if this was a valve problem (which btw it isn't) you'll have to wait for parts 2 for the answer!
0:50 "Can't get it to run properly" and "Carb rebuild kit" always go hand in hand. Unless it's genuine Honda brass, it'll never run right. Reproduction brass is garbage. 3:19 PD carbs. Yuck. And that vent line? WTF? Either the levels are set too high or the needles not seating properly. If it's the later, it's due to cheap brass (Keyster being the usual culprit). 14:30 You can remove the carbs without removing the airbox and battery, you just need to loosen all the fasteners. It's a bear of a job anyway, no point making more work.
Agree on the carb rebuild kit, genuine Honda fuel valves and seats if available, proper "o" rings too. Remove carbs on a CB500/550 just undo the manifold bolts makes job a breeze. would not be surprised if it was valve seat wear (regression) causing he low compression, common on 70's in line 4's, Honda using cheap stuff. Open valve clearance up a bit will give you some compression back. Jim, please tell us what you found please? Remember to fully loosen all the tappets before you put the rocker cover back on.. Genuine Honda head gasket AND a small bit of 3-bond is all you need to stop the classic head weep.
NO WAY. Compression that low wouldn’t be righted by warming the engine up. They’re about 70psi down. It’s more interesting that they uniformly low. I recon it’s a cocktail of issues.
@@memybikeni9931 thats the point... If there was really compression issues whats the chance they would all be uniformily low.... Especially with such a low millage engine. If you had run that engine for a few hundred miles and then rechecked I bet you would have been suprised. Moot point now its already taken down. Hey if the customer has the cash to spend then it really dosent matter.
Well there’s is a compression issue. Either warn rings or valve issues across all cylinders or just across the head affecting all of the cylinders, or a crack somewhere. Whatever it is no amount of running would get these numbers back up to near factory.
have you done a part 2?? i can not find it
Man your channel is amazing, you deserve couple millions of subscribers in my opinion, at least.
Proper old school tinkering. Looking forward to part 2.
Looking forward to part 2
Still waiting for part two.........
Have I missed something?
Can't actually find it in the video list, or did the owner had a change of mind ?
Yes I was thinking the same 👍
Me as well, just looked everywhere for it
Love this, I've got a few old 70's Hondas so this is right up my street :)
Had problems with the 'O' rings between the cylinder head & the inlet manifolds. They shrink & split causing untold problems.
Can't wait for part 2
This video made me anxious to see what my bike has compression wise.
*PLEASE can you tell me what did you twist to make the choke stay up? Thank you kindly*
I think the addition of the woodburner adds another dimension to your zen like analysis.
Great vid. It'll be interesting to see your method for compressing the rings and getting the pistons back in the barrels. Nice one Jim.
That was a very arty opening shot there! I enjoy your work, waffle and all. Cheers.
LOL! You reference the log burner just as I thought..."Oh shiiiit"
🤣
Is there a a part2?
great vid as usual nice to see you posting again.
Great vid as always! Thanks for sharing your wealth of knowledge. Your approach to problem solving is very helpful because I often struggle to know where to start and what process to follow. Keep up the good work
You see the best thing to do Jim is drop the Part 1 from the title and people will stop bugging you for Part 2 🤣🤣🤣 I love your channel, and appreciate the technical advice you give. Merry Christmas mate and Happy New Year. Rich
Merry Christmas and Happy New Year back to you dude, Thanks for the comments! You're probably spot on with using Part 1 in the title. I've set everyone's expectations. There will be a part 2 Jan I promise :)
Was there ever a part 2, can't seem to find it?
Time lapse was a great idea 👍
Nice video, good to see you posting again.Given the state of the piston heads to me it looks like it had been burning oil.
Will using the handlebar engine kill switch protect the ignition from damage while pressure testing, instead or removing wiring from coils etc?
Yes it would because you are switching off power to the ignition coils in most cases. However with an awful lot of bikes this also stops the starter from working which is annoying :) Very good point though.
You should always adjust the valve clearance before you check compression.
That's not exactly true, You should always make sure there's at least some clearance so you can guarantee the valve is completely shut.
Compression stabilizer sometimes works with engine which has not been run for a while
nice to see yea again Jim :-)
please was there any more vid's on the cb550??????
Sorry...it was filmed but never made it through the edit.
@@SuperbikeSurgeryTV Ok chap. I’ll suffer in silence 🥲
Is there a part two. Can't seem to find it.
Great video,when's the next one??
Great work Jim, very informative loving the channel .
10000
#honda
great vid this is going to be interesting. Cheers mate
do yourself a favor and take out all plugs when doing compression check. The engine will give you a more accurate reading across all cylinders. Also I would have squirted some oil into the combustion chambers after each initial test to see if the readings change. You would have known if the bores/pistons or valves are at fault!
The difference with plugs in of out is so small its basically insignificant, and would make not difference to the diagnosis. Obviously if it appears to crank slowly then its a problem but that wasn't the case. As I said in the Video if you need more of an accurate diagnosis in terms of how you are losing the compression without stripping the engine you should be doing a cylinder leak down test. The oil in the cylinder trick is a bit of a hit or miss thing and wouldn't tell you if it was Inlet or exhaust valves.
Don't you have to remove the engine from the frame to take the head off? Also, you tested compression cold and with the motor not been running for a long time - it might be better after running , getting all the rings loosened up and lubricated, what do you think?
Hi Paul, As you can see the head and barrels are easily removed with the engine still in the frame. With some bikes this isn't possible because the frame gets in the way. And with others it's possible but you're better off just taking the engine out because access is so poor and removing the engine is the quickest option. You are spot on that a compression test whenever possible should be done on an engine as close to operating temp as you can get it. Generally speaking you would only see a difference of a few psi between hot and cold. Sometimes the hot readings are lower. The way to think about it is if you had an engine in perfect condition would you expect to see readings under the min specification if you did a cold test!
Not on the 550 Paul. On the 750, yes, unless you fit a weldless frame kit (well worth the small investment IMO).
Part2 ????
Part 2 is..............
Would there be no value in a shot of oil in the bores, and then a re-test to rule out piston rings ? Even for information's sake. In other words, what are the chances of it being bad rings in all four cylinders? Subscribed by the way, and thanks.
Excellent
My prediction is head gasket, too many cylinders with low compression. Love this engine.
Check compression soon?
How I wish I could work on my CB750 head while it was still in the frame... ahhhh, the little things.
Haha, yes! I'm also a fan of being able to remove the 550 engine unassisted! (Although still not easy).
What happened to the other parts?
They were filled but never made it into the edit. Just way too busy.
Great stuff! Looking forward to more parts.
Amateur Question: How did you know the head had to come off before checking valve clearances?
Thats not an amateur question at all, it's a really intelligent one! I'm surprised you are the first person to ask it! You'll notice in the timelapse at the end that I remove the end cover for the crank and both valve adjusting caps on number 4 cylinder.
I get that cylinder at TDC on compression and just feel for some clearance by hand.
Given that all the Cylinders are down on compression by about the same amount its it's highly unlikely to be tight valve clearances. However you are spot on, it's something that needs looking at before stripping. I should probably have mentioned it but didn't.
I'll talk about it in part 2!
And part 2?
Not getting any younger Jim...... where’s part 2....? 🤣
Top job
Blimey that was quick!
Fala gringo estou mexendo em uma dessa aqui no Brasil.
Hi there. where's parts two?
Really sorry but it didn't make the edit for various reasons.
@@SuperbikeSurgeryTV I see. Well, sorry to hear. I really enjoyed part one, so of course I would have loved to see the rest of the build 😊
So you took a motor that had been sitting, started it once then ran compression and pulled the top end. Why not start up, warm it up, run it hard, set the valves and check the compression?
The engine had been run a couple of months ago by the previous owner attempting to fix it. No amount of running "hard" or otherwise is going to get this engine anywhere near the min compression spec. When doing a compression test you just need to make sure you have a clearance. A few thou out either way won't make any different to the readings, so long as the valve is able to close completely.
@@SuperbikeSurgeryTV The problem is that if the bike has been sitting, carbon and other crap can come loose and stick to the valves. Running them helps to ensure that the crap is blown out. Have seem compression go up on a motor that has set after a good run more than once.
@@maxheadflow "Carbon and other crap can just come loose"?? What other crap? And have you ever tried cleaning carbon off the head of a valve? There is no way it's just happening to fall off and get stuck on the valve seat on EVERY cylinder after standing for a couple of months.
I've seen engines that have stood for years and years have problems with rusty valve seats but this is only on the valves that happen to be open when the engine was last turning.
@@SuperbikeSurgeryTV From sitting, yes. Generally from the combustion chamber. If the bike hasn't been run hard carbon can flake loose and stick the valve faces. I've cleaned lots of valves. I've seen relatively new bikes (back when these were new) have this issues.
@@maxheadflow 30 years at this and I've never come across it?? However the point I was making was you wouldn't get consistently low compression across all the cylinders if this was a valve problem (which btw it isn't) you'll have to wait for parts 2 for the answer!
Part 2?????
It's coming I promise 😬
Those 4 into 1 carb kit needles and seats are terrible...
WHERES PART 2........??????? 🤷🏼♂️🤣
It's coming soon I promise :)
Superbike Surgery Ltd
Sweet....! Nothing else worth watching on UA-cam 🤣🤣🤣
Ok my question about removing the whole engine was stupid, sorry about that
Whatever happened to this 🤷🏼♂️🤷🏼♂️🤷🏼♂️
Part 2 is all filmed, need to find the time to get too the edit. Unfortunately not a priority because no one is paying me!
Superbike Surgery Ltd Do it for the fans 🤣🤣
@@taswr I promise I'll get to it soon, I'm working 12 hours a day at the moment just trying to keep up so there is literally no time!
Superbike Surgery Ltd Being busy is a good problem to have mate👍🏻
@@SuperbikeSurgeryTV do it for fun and for free. for your fans and subscribers mate. but please do it.
0:50 "Can't get it to run properly" and "Carb rebuild kit" always go hand in hand. Unless it's genuine Honda brass, it'll never run right. Reproduction brass is garbage.
3:19 PD carbs. Yuck. And that vent line? WTF? Either the levels are set too high or the needles not seating properly. If it's the later, it's due to cheap brass (Keyster being the usual culprit).
14:30 You can remove the carbs without removing the airbox and battery, you just need to loosen all the fasteners. It's a bear of a job anyway, no point making more work.
Agree on the carb rebuild kit, genuine Honda fuel valves and seats if available, proper "o" rings too. Remove carbs on a CB500/550 just undo the manifold bolts makes job a breeze. would not be surprised if it was valve seat wear (regression) causing he low compression, common on 70's in line 4's, Honda using cheap stuff. Open valve clearance up a bit will give you some compression back. Jim, please tell us what you found please? Remember to fully loosen all the tappets before you put the rocker cover back on.. Genuine Honda head gasket AND a small bit of 3-bond is all you need to stop the classic head weep.
I would run that engine for a while before I would worry about those compression numbers.. Un less money is no concern...
NO WAY. Compression that low wouldn’t be righted by warming the engine up. They’re about 70psi down. It’s more interesting that they uniformly low. I recon it’s a cocktail of issues.
@@memybikeni9931 thats the point... If there was really compression issues whats the chance they would all be uniformily low.... Especially with such a low millage engine. If you had run that engine for a few hundred miles and then rechecked I bet you would have been suprised. Moot point now its already taken down. Hey if the customer has the cash to spend then it really dosent matter.
Well there’s is a compression issue. Either warn rings or valve issues across all cylinders or just across the head affecting all of the cylinders, or a crack somewhere. Whatever it is no amount of running would get these numbers back up to near factory.
@@Psycrow11 those compression numbers are 40-45% down on spec, running the engine for a while isn't going to fix that.