postoak_imp
Been there
I see the problem! They forgot to install the piston return springs on your Honda. 
Engine rebuild...
- Thread starter QUINTtastic_imp
- Start date
QUINTtastic_imp
First service completed
Thread starter
Oh darn! I’ll make sure to let them knowpostoak_imp said:I see the problem! They forgot to install the piston return springs on your Honda.
glenncal1_imp
Running like a top
I would certainly try to get your gas tested, but of course it may have nothing to do with whats in you current tank. IMHO (not worth much I admit) there had to be some contamination at some point. I don't see how that would be a mechanical issue, but who knows.
flynrider
Road warrior
I'm inclined to agree that some form of contamination led to the excessive carbon build up on top of the pistons. Who knows when it happened. For all you know, this could be something that started with the previous owner.
The only time I've seen anything like this was an old Kaw 750 twin engine I tore down for a friend. He'd had it stored in the garage for years and would start it up occasionally to "keep the top end oiled". This is generally not a good practice, but to make matters worse, the gasoline in the tank was well over 2 years old and had degraded to the point where it smelled like turpentine. On pulling the head, I found a thick layer of carbon deposits on all of the piston tops and scored cylinder walls.
The only time I've seen anything like this was an old Kaw 750 twin engine I tore down for a friend. He'd had it stored in the garage for years and would start it up occasionally to "keep the top end oiled". This is generally not a good practice, but to make matters worse, the gasoline in the tank was well over 2 years old and had degraded to the point where it smelled like turpentine. On pulling the head, I found a thick layer of carbon deposits on all of the piston tops and scored cylinder walls.
beardyweirdy@me.com_imp
Been there
Hey QUINTtastic, That's a bummer! I unfortunately have a set of pics just like those, not from my CB tho. I had a bike that had it's petrol tank sealed by a previous owner. The newer fuel, with high ethanol and the like, had broken down the sealant and washed it into the engine. Is there any chancy someone could have sealed the tank previously? They are all long shots but could be....
QUINTtastic_imp
First service completed
Thread starter
Yeah I have no clue. The first owner put 7k miles on it over the first 4 or so years of the bikes life. I put 4K miles on it in 4 months, so I’ve never had the same gas sitting in it for long aside from winter with stabil in it.Flynrider_imp said:
It’s just something I have to deal with, financially haha. Oy vey
Oh no this bike was too new and too babied to have that happen. Crazy how so many different scenarios have done this to peoples bikes. Sad sad times. I can’t wait to crawl up in fetal position after I hand the dealer my credit cardbeardyweirdy@me.com_imp said:
PowerDubs_imp
Road warrior
You hit the nail on the head- babied engines build carbon.
There is a head and pistons on Ebay from a 4k mile motor that is just as black as yours. Go look.
I think a lot of guys would be surprised if they opened their engine.
The bike has a lot of owners that only do 2-3k revs lightly. That will cause carbon buildup.
I'm a firm believer in giving an engine the beans fairly often- italian tune up, to literally blow out / burn off the gunk.
All that being said- I do not think the carbon had anything to do with your valve issue.
And on the bright side- you will be the first guy with the factory honda oversize pistons.
If I remember correctly that is like a whole 8cc.
There is a head and pistons on Ebay from a 4k mile motor that is just as black as yours. Go look.
I think a lot of guys would be surprised if they opened their engine.
The bike has a lot of owners that only do 2-3k revs lightly. That will cause carbon buildup.
I'm a firm believer in giving an engine the beans fairly often- italian tune up, to literally blow out / burn off the gunk.
All that being said- I do not think the carbon had anything to do with your valve issue.
And on the bright side- you will be the first guy with the factory honda oversize pistons.
If I remember correctly that is like a whole 8cc.
QUINTtastic_imp
First service completed
Thread starter
Yeah the bikes manual has stupid low shift points. When I read it I thought “yeah okay honda.. that’s realistic..” (then again this might be the recommendation for all their bikes.PowerDubs_imp said:You hit the nail on the head- babied engines build carbon.
There is a head and pistons on Ebay from a 4k mile motor that is just as black as yours. Go look.
I think a lot of guys would be surprised if they opened their engine.
The bike has a lot of owners that only do 2-3k revs lightly. That will cause carbon buildup.
I'm a firm believer in giving an engine the beans fairly often- italian tune up, to literally blow out / burn off the gunk.
All that being said- I do not think the carbon had anything to do with your valve issue.
And on the bright side- you will be the first guy with the factory honda oversize pistons.
If I remember correctly that is like a whole 8cc.
I generally shift between 4-5k but sometimes higher as my favorite thing about this bike is how fun it is to bang through the gears from a stop. It may not be a sport bike by today’s standards or anything too fancy, but I sure love the torque it has. I’m not sure if you’ve looked up the cb1100s torque graph but it’s basically a straight increasing line with no dips or plateauing.
I haven’t asked about what piston size they’re putting in. I’ll have to do that tomorrow. I may get it back then. Too bad they didn’t wanna hone it out more and make it a cb1200
Retsel_imp
Been there
I add Sea Foam regularly. I've never had a problem with an engine that I used it on but, can't say I would have without it. Just covering basis. I'm not a real religious man however, I still pray as well.
Sent from my Moto G (5) Plus using Tapatalk
Sent from my Moto G (5) Plus using Tapatalk
Jeeves_imp
First service completed
QUINTtastic_imp
First service completed
Thread starter
Hey, yeah I will be using some additives from now on. Although we shouldn’t have to use any additives whatsoever on a 2018 Honda, ya know? As long as we use spec oil and gas, as well as do the proper maintenance.. we SHOULD be good.Jeeves_imp said:
QUINTtastic_imp
First service completed
Thread starter
UPDATE: They replaces the pistons, a valve, some gaskets, and adjusted the balancer. STILL HAS MASSIVE VIBES. Yay
peterbaron
Road warrior
WHAT!!!!, engine pre-diagnosed, taken apart and still has the same issue after repairQUINTtastic_imp said:
:huh:Houtman_imp
Road warrior
Crank shaft problem ?
Does not sound good.
beardyweirdy@me.com_imp
Been there
Have you had a play with balance shaft adjuster?
max
Road warrior
Thanks for the nice pictures, as you can tell you have our attention.
As a sympathetic audience we could do with some more information;
does the vibration happen when the engine is stationary and at what revs is it worse?
Is there a noticeable lack of drive and when the engine warms up are all four pipes getting hot at the same pace?
It happened from one second to the other, i wonder if the cylinders are contributing equally or if an injector is not working as it should
Found a picture of another cb1100 cylinder with cleaned pistons in front, notice the scraping on all 4 pistons/cyl's.
(click twice for larger image)
Not sure why pistons all score in the same place and I guess your cylinders were scored deeper?
And looking at where the scoring takes place ( well below the rings ) it makes me wonder if it's not something in the oil that gets splashed up to the cylinder walls that causes this?
I mean how does the carbon get past the rings unnoticed and settles below the rings to scrape away at both parts?
I'm sure we all feel the unbelievable misfortune that happened to you and wish for a fair outcome from Honda.
As a sympathetic audience we could do with some more information;
does the vibration happen when the engine is stationary and at what revs is it worse?
Is there a noticeable lack of drive and when the engine warms up are all four pipes getting hot at the same pace?
It happened from one second to the other, i wonder if the cylinders are contributing equally or if an injector is not working as it should
Found a picture of another cb1100 cylinder with cleaned pistons in front, notice the scraping on all 4 pistons/cyl's.
(click twice for larger image)
Not sure why pistons all score in the same place and I guess your cylinders were scored deeper?
And looking at where the scoring takes place ( well below the rings ) it makes me wonder if it's not something in the oil that gets splashed up to the cylinder walls that causes this?
I mean how does the carbon get past the rings unnoticed and settles below the rings to scrape away at both parts?
I'm sure we all feel the unbelievable misfortune that happened to you and wish for a fair outcome from Honda.
jimgl3_imp
Been there
what kind of shop "repairs" your motor and returns it still "massively vibrating"?
max, I think the scouring on the pistons is caused by the splash lubrication(or the lack of it) rather than carbon, probably caused by low oil level and/or low rpms. The scour area is typical for this kind of damage; it is where the pistons "lean" against the cylinder walls when bobbing up and down.max_imp said:Thanks for the nice pictures, as you can tell you have our attention.
As a sympathetic audience we could do with some more information;
does the vibration happen when the engine is stationary and at what revs is it worse?
Is there a noticeable lack of drive and when the engine warms up are all four pipes getting hot at the same pace?
It happened from one second to the other, i wonder if the cylinders are contributing equally or if an injector is not working as it should
Found a picture of another cb1100 cylinder with cleaned pistons in front, notice the scraping on all 4 pistons/cyl's.
(click twice for larger image)
Not sure why pistons all score in the same place and I guess your cylinders were scored deeper?
And looking at where the scoring takes place ( well below the rings ) it makes me wonder if it's not something in the oil that gets splashed up to the cylinder walls that causes this?
I mean how does the carbon get past the rings unnoticed and settles below the rings to scrape away at both parts?
I'm sure we all feel the unbelievable misfortune that happened to you and wish for a fair outcome from Honda.
I had a similar experience in the past, not with a motorcycle engine but a marine diesel. It was a Magirus-Deutz air cooled 4-cyl. I installed the engine(which was 20 years old already) in my wooden fishing boat and sailed away. But I was in such a hurry to reach my home port I didn't bother with cooling air inlets and outlets, I just left the engine room lid open. But then because of the noise the engine makes(airhead, remember?
) I had to keep the rpms down. Fast forward 120 hours, I have trouble starting. When we opened up the top that was exactly what I'd seen.Of course that engine was designed as a German workhorse, so the problem was solved with light sanding of cylinder walls and new rings...
Definitely not the exercise recommended for a Honda Ah, by the way, that engine is still operational I believe, must be 50+ years old by now. Oh boy, I massively drifted off subject...
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