Wow a small world! I recently purchased this very motorcycle! I can tell it's the same one by the mismatched tyres, slightly rusty spokes, and the imperfections in the rear mudguard. Also the lack of trim on the seat with the strap that's been re used with its rusty buttons. Oh and the dealer told me about the work it received to fix the smoking issue. I've done approx 500 miles on it and it seems fine though I'm told there is still a slight haze when opened up properly. Oil consumption seems reasonable so I'm happy for now!
Your daughter was brilliant in the vid and of course watching you work under pressure very funny you have to love old hondas still going after 40 years
You don’t need to apologize for having to interact with your kids, it does not detract in any way from the quality of your video. Remember, you should never ever put your TH-cam above your family.. not suggesting that you would. I’m liking this old Honda, I had one in 1990 and of course it was a classic bike then. My exhausts were rusty so I put on a 4-1 exhaust which in retrospect was a mistake. I wasn’t worth anything and had not been well maintained but it ran ok except the engine was very noisy compared to more modern bikes. I can’t help wondering if the answer for that particular bike may have been to just live with that smoke for a while and see if it settled down after a while, it may be (I’m guessing) that it would not get much use anyway. At least you would get to see under what real life conditions the smoke got better or worse.. but I guess that’s why you are a bike mechanic and I am not!
Good analysis. You clearly has valve issues. My 350-4 was smoking bad, rebuilt the head completely, made no difference. Pulled the cylinders off and found the culprit. Oil rings on two and four were broken in half. Most likely, someone tried installing the cylinder barrel assembly by him or herself without the proper tools.
great vid, not that i have to point out, but i think your on the right track with your findings, and it does sort of shout at you when your valve guide is so loose in its bore when usually you have to heat the head up to extract and install valve guides.
I had the same problem on my Triumph Trident, It did not smoke when cold but once it got warm I found one of the valve guides was moving and was allowing oil to get passed, just a suggestion hope this helps. I love your little apprentice.
A young mechanic in the making lol. You should encourage her she could take over your business when you retire. My dad always was happy to entertain me in everything he did.
Listening to your mind work is very educational...knowing the history of a bike is worth alot when diagnosing this kind of problem, well done.Those stock exhaust pipes are not cheap.!
Very interesting video, as it shows just what can go wrong and be very frustrating at times. Fingers crossed and look forward to seeing the next video on this.
So if the head isn’t cracked what would cause the valve stem to be so loose ? Great vid and it took me an hour to watch it even though it was 30 minutes as my little girl needed chocolate, drink, cherry bakewell, and there was a Lego emergency 🙄
I did 100,000 miles on a CB500/4 with no major issues, but I do know there are valve stem oil seals on the top of the valve guides. Should be the same on the CB350. During the 100,000 miles I replaced the rockers (hardness wear), the head gasket (slight oil leak on the side), and at 100,000 miles replaced the clutch plates due to it getting a bit grabby - never slipped though. Everything else was just wear and tear, chains and sprockets, brake pads and shoes etc. Its the bike I kept for longest and did the most miles on. Just did everything really well.
Any chance the guide could have been turning slightly once the engine had warmed up so slightly wearing the head where it fits ? hence why it drifted out easy
I’m a 71 year old motorcyclist and have worked on and off in the motorcycle industry. Where did you get a new 4 into 4 exhaust? Parts like that are extremely hard to source for bikes from that era. Has Honda made a run of pipes for these? God they must have been painfully expensive!
@Review Master So you don't know what the problem was then? Just fire a load of parts at it until its fixed 🤣 FYI it had new exhaust valves and the valves lapped in, new stem seals on the inlet side, and a hone with new rings. Why on earth you would want to replace value seats I've know idea. I've probably built over 50 of the old school Honda Four engines over the last 30 years 350,400,550,750 and not one of them ever needed the value seats replacing. I've no idea what "Water Blasting" is, I can only assume you mean "Vapour blasting" which I do a lot of! In this instance the customer didn't want the extra cost involved.
@Review Master That's very gracious of you 👍. The problem was a valve guide becoming loose in the head when the engine got up to temperature. They also have a small O-RING fitted underneath the guide which had done the usual thing and turned to concrete.
Not bike engine... But I've had car engines E.G Toyota 4AGE smoke pretty bad especially when you would tap on and off power, it was the valve gades.. especially when it would get hot it would suck oil past the seal via the gades
Wow a small world! I recently purchased this very motorcycle! I can tell it's the same one by the mismatched tyres, slightly rusty spokes, and the imperfections in the rear mudguard. Also the lack of trim on the seat with the strap that's been re used with its rusty buttons. Oh and the dealer told me about the work it received to fix the smoking issue. I've done approx 500 miles on it and it seems fine though I'm told there is still a slight haze when opened up properly. Oil consumption seems reasonable so I'm happy for now!
Great to hear things worked out.
Wow that IS a small world round about.
Your daughter was brilliant in the vid and of course watching you work under pressure very funny you have to love old hondas still going after 40 years
This was a great watch! I love these old sohc/4 Hondas, they're both frustrating and rewarding all at the same time.
You don’t need to apologize for having to interact with your kids, it does not detract in any way from the quality of your video. Remember, you should never ever put your TH-cam above your family.. not suggesting that you would. I’m liking this old Honda, I had one in 1990 and of course it was a classic bike then. My exhausts were rusty so I put on a 4-1 exhaust which in retrospect was a mistake. I wasn’t worth anything and had not been well maintained but it ran ok except the engine was very noisy compared to more modern bikes. I can’t help wondering if the answer for that particular bike may have been to just live with that smoke for a while and see if it settled down after a while, it may be (I’m guessing) that it would not get much use anyway. At least you would get to see under what real life conditions the smoke got better or worse.. but I guess that’s why you are a bike mechanic and I am not!
Good analysis. You clearly has valve issues.
My 350-4 was smoking bad, rebuilt the head completely, made no difference.
Pulled the cylinders off and found the culprit.
Oil rings on two and four were broken in half.
Most likely, someone tried installing the cylinder barrel assembly by him or herself without the proper tools.
Great video Jim and the spark pluggy thingy was hilarious !
Keep 'em coming ! 👍
Jim well done.ur a great dad. Ur vids are all ways good an interesting. And helpful. .a great dad and a great mechanic.
great vid, not that i have to point out, but i think your on the right track with your findings, and it does sort of shout at you when your valve guide is so loose in its bore when usually you have to heat the head up to extract and install valve guides.
I had the same problem on my Triumph Trident, It did not smoke when cold but once it got warm I found one of the valve guides was moving and was allowing oil to get passed, just a suggestion hope this helps. I love your little apprentice.
Jim they are forever now known as Spark Pluggies 🤣🤣
HERE HERE! Just imagine your dealers face when you ask for some ngk spark pluggies. :)
Pllllugs :)
This motion has officially passed. They will forever be known as Spark Pluggies...😂
very insightful! i’m learning a lot from your channel since yesterday. thanks for the uploads :)
A young mechanic in the making lol. You should encourage her she could take over your business when you retire. My dad always was happy to entertain me in everything he did.
Lockdown, kids, motorcycles - what could possibly go wrong! 😂 Another very interesting video Jim 👍👍
Love these videos.Very interesting and nice to have the “little helpers” doing what they do best😂.
Listening to your mind work is very educational...knowing the history of a bike is worth alot
when diagnosing this kind of problem, well done.Those stock exhaust pipes are not cheap.!
Very interesting video, as it shows just what can go wrong and be very frustrating at times. Fingers crossed and look forward to seeing the next video on this.
Love it!! You crack me up. Thanks for the laugh. Totally get the dad thing. Great videos. keep them coming
3 years im here today , Best i press play thanks dude
Daddy talking to internet - go away hehehehe - it make me so smile. :) - btw excelent diagnose
Bwahaaaaaa! “Sammy, go away.! Good boy! “..... 🤣
Did you get this sorted in the end, my favorite bike of all time.
Nice one, Jim ;) However, the one big problem with your YT vids is that........we don't get enough of them :(
Jes you are still alive and kicking!!
I teach primary, you did very well...so impressed.
"Hello" always wear your cycle helmet....pink nice.
⭐⭐⭐
So if the head isn’t cracked what would cause the valve stem to be so loose ? Great vid and it took me an hour to watch it even though it was 30 minutes as my little girl needed chocolate, drink, cherry bakewell, and there was a Lego emergency 🙄
I did 100,000 miles on a CB500/4 with no major issues, but I do know there are valve stem oil seals on the top of the valve guides. Should be the same on the CB350.
During the 100,000 miles I replaced the rockers (hardness wear), the head gasket (slight oil leak on the side), and at 100,000 miles replaced the clutch plates due to it getting a bit grabby - never slipped though. Everything else was just wear and tear, chains and sprockets, brake pads and shoes etc.
Its the bike I kept for longest and did the most miles on. Just did everything really well.
The Honda CG125 also doesn't have a seal on the exhaust valve guide.
Haha no need to apologize for your kid..
Just built a race bike . Same cylinder smoking its ass off ! Knocks you back when you put so much work in just to go backwards
Is there a sequel to this one Jim, I would like to know the outcome.
After the head was skimmed, was a dye penetrant check performed for micro-cracks?
No it wasn't, but In hindsight it would have been a good idea.
Any chance the guide could have been turning slightly once the engine had warmed up so slightly wearing the head where it fits ? hence why it drifted out easy
What endoscope are you using? Definable need on to inspect my CB550!
www.amazon.co.uk/dp/B01NBFTAHE/ref=cm_sw_r_cp_apa_glc_fabc_N3FWEEWDGCS3P7DE01Z8
Welding supplies 3 tins always handy... Not if you are a welder and the inspector holding them.
I’m a 71 year old motorcyclist and have worked on and off in the motorcycle industry. Where did you get a new 4 into 4 exhaust? Parts like that are extremely hard to source for bikes from that era. Has Honda made a run of pipes for these? God they must have been painfully expensive!
Hows the big O ring around the base of the no 2 cyl
Hi, Did You solve the problem? I was in the same thing, I think I know what causes the oil smoke. It's not the head.
Remember the 360 to
Maybe the previous owner reamed the guides and this one was slightly oversized, did you mick the valve stems to see if they are all within spec too?
It's had new exhaust valves. The original were borderline...
@Review Master Wow thanks for the positivity 😁 I bow to your superior knowledge. Based on the evidence in the video what was the problem?
@Review Master So you don't know what the problem was then? Just fire a load of parts at it until its fixed 🤣 FYI it had new exhaust valves and the valves lapped in, new stem seals on the inlet side, and a hone with new rings. Why on earth you would want to replace value seats I've know idea. I've probably built over 50 of the old school Honda Four engines over the last 30 years 350,400,550,750 and not one of them ever needed the value seats replacing. I've no idea what "Water Blasting" is, I can only assume you mean "Vapour blasting" which I do a lot of! In this instance the customer didn't want the extra cost involved.
@Review Master Nope....all the guides were within the acceptable service limit.
@Review Master That's very gracious of you 👍. The problem was a valve guide becoming loose in the head when the engine got up to temperature. They also have a small O-RING fitted underneath the guide which had done the usual thing and turned to concrete.
Brilliant vid jim, child labour who said it was not PC
I went through the exact same issue cb550k I mean exactly
9 months later but really keen to know what happened
Have you got a smoke tester machine it could find your leak.
As the head warms up is there a gap between the guide and head ...🤔
Just made a comment forgetting it's 9 months old 😁
Not bike engine... But I've had car engines E.G Toyota 4AGE smoke pretty bad especially when you would tap on and off power, it was the valve gades.. especially when it would get hot it would suck oil past the seal via the gades
Is it possible the Oil scraper ring on the piston has stuck in the groove.
My 650 smoked until my carbs were cleaned and insinct
what happened??
Great video have a 1977 cb400f very similar engine informative cute daughter "spark plugie"
20:17 Oh, fuckin' hello! I've seen this one, oil leaking past the valve guide. Easiest fix is a second hand head.
At least she didn't say I did a poo in it 😂
Crosshatch doesn't look so clever on 2
Did your daughter star in outnumbered 10 years ago?