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At what gear did you feel the vibes? I did feel them too but after my 1st service they were down. I observed them in 2nd gear mostly at 40kmph. 3rd at 40 to 50 it’s butter smooth. Rubbing sound at the rear? Might be some mud. I previously had a 2014 RE tb350 so it’s almost none vibes for me when compared 😅
 

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Hi Ben,

Only one vidio showing the tdc reference wire pointer ?

Seen your picture of the cdi crank position sensor......

So there is some "wobble" of the alternate rotor, but it's within spec ?

How much of a wobble is it ?

1mm or more ?

Also some end float seen, in and out movement, how much is it please ?

The rotor timing marks are a bit difficult to see in your vidio, but you may see them very clearly. You sure they are to spec and not over advancing ?

So no frame and cycle parts vibrating badly making a buzzing noise.

The ign " bolt" welded to the crank may be an issue, adding or subtracting to imbalance, but it will have some effect.

As you know, it's mass may be small, but a 5k revs, it's "effective mass" may be considerable. What's done is done.

Do you have the old parts to convert it back to points ignition ?

Cylinder head gasket protrusion into the combustion space may be/could cause an issue but you are confident the piston crowns do not make contact.

I wonder how the head gasket sealing ring is surviving it's "torture"....

Back later after chores and a re read of your last post....
 

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Discussion Starter · #23 ·
At what gear did you feel the vibes? I did feel them too but after my 1st service they were down. I observed them in 2nd gear mostly at 40kmph. 3rd at 40 to 50 it’s butter smooth. Rubbing sound at the rear? Might be some mud. I previously had a 2014 RE tb350 so it’s almost none vibes for me when compared 😅
At all gears and I am not hearing any sounds. It isn't chassies related but engine I am afraid :(
 

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Discussion Starter · #24 ·
And back at your questions again - sorry for the delay.
I also updated my earlier photo section back a few posts with descriptions. Could you guys look at it again?

Only one vidio showing the tdc reference wire pointer ?
Here is the video showing the crank vibration - it is slow motion so should be ok to see how it is out of true. I have no idea if it is within tolerance or not....
Crankshaft out of true - slowmotion

And yes - the TDC hack is made of barb wire and I only slip it on when I check timing. Here on the slow motion video that piece is not there.

Seen your picture of the cdi crank position sensor......
Not a very elegant solution - was done before I got the bike....

So there is some "wobble" of the alternate rotor, but it's within spec ?
I have no idea how to tell... :(

How much of a wobble is it ?
I'd say a 1mm or 1.5mm tops? Not sure how to check this accurately, please see the slow motion video.

1mm or more ?
Yes at least 1...

Also some end float seen, in and out movement, how much is it please ?
I don't know how I could check this but I remember there was some some in-out movement when I assembled the engine. I'd say at least 1-2mm's but I can't recollect this clearly.

The rotor timing marks are a bit difficult to see in your vidio, but you may see them very clearly. You sure they are to spec and not over advancing ?
Yes the timing is now spot on. Hard to take a nice video of the flashing light...It isn't over advancing but then again, I didn't try past 3-4k RPM as the oil is spraying like crazy :) What I did see is as I apply the throttle, the advance mark moves closer and closer to TDC and at one point it reaches it and then stays there - won't go any futher.
So at idle RPM it is the "F" mark and as I go beyond the advance markers are moving closer and at around 2-2.5K (guess only) it reaches it and stays on - won't advance further even though I apply more throttle. Hope my silly explanation is somewhat understandable....

So no frame and cycle parts vibrating badly making a buzzing noise.
Nothing that I've noticed. I do feel the footpegs and the handle vibrating a little though... Nothing rattles.

The ign " bolt" welded to the crank may be an issue, adding or subtracting to imbalance, but it will have some effect.

As you know, it's mass may be small, but a 5k revs, it's "effective mass" may be considerable. What's done is done.


Yes I fully understand this but I think the flywheel being out of true would create an even more considerable vibration?

Do you have the old parts to convert it back to points ignition ?

No I don't but I started buying them and will eventually go back to points if I can't figure this out.

Cylinder head gasket protrusion into the combustion space may be/could cause an issue but you are confident the piston crowns do not make contact.

I'd like to believe so that I am confident :)

I wonder how the head gasket sealing ring is surviving it's "torture"....
I won't be able to tell unless I open the engine up. Hope they are ok! When I got the bike it already had a 47mm piston in it so was overbored and using a stock gasket. When I did the rebuild. I did not notice anything strange looking at the gasket.
Then I got a new block with a standard bore (with minor scratches) and pistons for it (0.25 over) - just to find out noone can bore the block for these small diameter pistons. The STD is 44mm so the one I wanted done was 44.25mm...

I went back to the block I got with the bike and got with the supercub pistons.

Thank you for all your help.
A quick update - I installed smaller carbs yesterday which are closer to the original in terms of specs and the bike runs better and doesn't lose power when hot. It is still hot though...
Raining now so can't test right away but when I had a chance to go for a longer run, I'll update back with plug colors etc.
Bike still vibrates of couse...
 

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In-out looks normal. What is not are the rollers, the slop in the chain tension, and a crank gear tooth that looks more worn than the rest. So maybe it's noise not vibration? Tighten the cam chain see if it helps.
 

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Hi Ben, I will have a proper view later this evening, I must crack on with the car, due for its annual mot test very soon. An annual safety inspection.

Do you have Vernier gauge it can measure endfloat ?

If not even a long bolt and nut, to record difference between in and out. A know pitch and number of degrees but turns to show difference...

A bit noisey here so audio not heard, cam chain very slack...

Can you take a picture further back to show top and bottom of engine please ?

Some more chewed screws seen....back later, 3 hours of daylight left. Coffee break over, back to the grindstone...
 

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Discussion Starter · #30 ·
In-out looks normal. What is not are the rollers, the slop in the chain tension, and a crank gear tooth that looks more worn than the rest. So maybe it's noise not vibration? Tighten the cam chain see if it helps.
Maybe I forgot to say in the video, I slackened the chain on purpose to be able to display the in-out play. With chain tensioned the play is harder to display.

Glad the in-out looks ok. Did you see I can also move the crank up and down a bit? Maybe .5mm

thanks!
Ben
 

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Discussion Starter · #31 ·
Hi Ben, I will have a proper view later this evening, I must crack on with the car, due for its annual mot test very soon. An annual safety inspection.

Do you have Vernier gauge it can measure endfloat ?

If not even a long bolt and nut, to record difference between in and out. A know pitch and number of degrees but turns to show difference...

A bit noisey here so audio not heard, cam chain very slack...

Can you take a picture further back to show top and bottom of engine please ?

Some more chewed screws seen....back later, 3 hours of daylight left. Coffee break over, back to the grindstone...
Good luck with the car!

I can’t measure the in and out play but hopefully you see in the video. When you are in a quieter environment please watch again, I explain a few things in the video.

I just sealed the engine up with liquid gasket as I had a few leaks, don’t want to open it up again unless necessary? I’ll look for a photo from further away. Hope this will do?

Enjoy the coffee!
The chewed screws show the hard life of bikes in Indonesia - and the inexperienced service centers. I’ll have them replaced…

Ben

Motor vehicle Automotive tire Automotive lighting Hood Automotive design
 

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Hi Ben, yes it's always helpfull to say a few "please God's". Once all the press plates where made the bearing replacement was all good, but the gauge said 4 tons to press out. A tight fit. Refitting was drama free. Both sides underneath on the front all done. Check service back end next then it's drivers seat, a little wobbly. Then all the simple stuff and get it booked in for its test. The aim is pass with no advisories as always.

Back to your bag of sweets.

You tube vidio not showing at all.

No picture of whole engine.

Would like to see vidio and listen to text.

A "still" picture of crank cam chain SPROCKET would be nice. Straight on, not a slight side view please.

Any strange noises when in gear and "drive" condition, IE throttle open, "over run" condition, IE throttle closed, and cruise condition, IE between the two conditions mentioned. Noise on clutch side perhaps......

Did you get endfloat measurement, even using a ruler ?

Looks more than one 1mm ?

I have some info but that's for after seeing/hearing vidio, and whole engine picture.

Take a measurement, ruler method you should be able to measure at least to half a mm reasonably, maybe 1/3mm or more ( less actually )...

Even a pair of dividers perhaps...

In your timing light vidio a remember seeing end float dancing, and wobble...

By dancing I mean seeing the rotor dancing in and out a bit.

Also, any evidence of a 3 leg puller being used to remove the alternator rotor at all ?

I hope you used a "bolt" the same size and thread as a "bolt" found on your bike perhaps ?

Over......
 

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Hi Ben, seen all the vision now, loved the slow motion one, and the noise !

Very rhythmic clunk.

Mark the alternator rotor "timing mark face" with a black reference line and re take a vidio. I presume your slowed the vidio via computer ?

Really good idea and very " telling" !

Out in the sticks you have to be resourcefully, adaptive, creative, inventive and all those other words and skills of a similar nature.

Dam good idea, we can all learn from that one.

I do not have specific data/info for your cb125k3 other than what is shown on CMSNL. I have another book to hunt down just in case info is in that one.

End float, in and out movement, axial play.....

Looking on CMSNL, the two main bearing crank ( with large centre rotating mass/flywheel, similar to old triumphs etc. ) Are roller type, in fact all the bearings, main and big end are roller type.


The primary drive gear which drives the clutch basket is "helical " not a straight cut gear, so during "drive" and "over run" a "thrust" is imposed on the crankshaft.

As far as I can see this thrust is controlled by a "washer".....

Looking at a picture of that thrust control ring, "washer" , it doesn't look very thick. I wonder how worn that is, or is it missing perhaps ?

End float looks a bit excessive to me.

Up and down play, radial play, again looks excessive to me.

Definite "wobble" in alternater rotor, damaged by a 3 leg puller ?, It something bent ?

Heat distortion due to that welded on "bolt" maybe ?

The picture of the engine in frame ( loose ) probably taken during assembly. Usually when engine at tdc, the cam sprocket "O" and the crankshaft "key" line up. By that I mean a line ( or straight edge, bit of string ) can get drawn thru cam shaft centre to crankshaft centre, lining up with the cylinder centre.

That's "usually" what can be done, but not always.

One of the cam sprocket bolts looks odd and I cannot see the O mark.

One of the final drive chain sprocket bolts look odd also, which can cause a problem.

Is the cdi unit "Arduino" based ?

So quite a worn engine really hut it is years old.

Why did they go down this route when the engine had points ignition ?

Why not "transistorised" points ignition, it getter still, why not light or hall effect triggered cdi system.

There is room on the oe points base disc for either, requiring a different points cam/advancer unit, or utilising the oe "twin cammed" advancer unit.

You know of xl125r I think, that has the cdi system sensor with centrifugal advancer, cam shaft driving, which "looks" as if it may fit the camshaft sticky outy shaft ?

Where do all the dead machines go to on your small island ? I found your island in the atlas.

Perhaps if there is a breakers yard or collection point for "scrap" and dead machines on the island, you should spend some time there ?

Anyways, what's done is done.

Use the bike avoiding the bad vibration period.

Avoid using instant gasket. Banana boxes have a usefull sheet of useable relatively thick cardboard that I have used, and still do, to successfully make gaskets, that work well and contain oil.

Phone battery dying now so back tomorrow, a new day.
 

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Hi Ben, seen all the vision now, loved the slow motion one, and the noise !

Very rhythmic clunk.

Mark the alternator rotor "timing mark face" with a black reference line and re take a vidio. I presume your slowed the vidio via computer ?

Really good idea and very " telling" !

Out in the sticks you have to be resourcefully, adaptive, creative, inventive and all those other words and skills of a similar nature.

Dam good idea, we can all learn from that one.

I do not have specific data/info for your cb125k3 other than what is shown on CMSNL. I have another book to hunt down just in case info is in that one.

End float, in and out movement, axial play.....

Looking on CMSNL, the two main bearing crank ( with large centre rotating mass/flywheel, similar to old triumphs etc. ) Are roller type, in fact all the bearings, main and big end are roller type.


The primary drive gear which drives the clutch basket is "helical " not a straight cut gear, so during "drive" and "over run" a "thrust" is imposed on the crankshaft.

As far as I can see this thrust is controlled by a "washer".....

Looking at a picture of that thrust control ring, "washer" , it doesn't look very thick. I wonder how worn that is, or is it missing perhaps ?

End float looks a bit excessive to me.

Up and down play, radial play, again looks excessive to me.

Definite "wobble" in alternater rotor, damaged by a 3 leg puller ?, It something bent ?

Heat distortion due to that welded on "bolt" maybe ?

The picture of the engine in frame ( loose ) probably taken during assembly. Usually when engine at tdc, the cam sprocket "O" and the crankshaft "key" line up. By that I mean a line ( or straight edge, bit of string ) can get drawn thru cam shaft centre to crankshaft centre, lining up with the cylinder centre.

That's "usually" what can be done, but not always.

One of the cam sprocket bolts looks odd and I cannot see the O mark.

One of the final drive chain sprocket bolts look odd also, which can cause a problem.

Is the cdi unit "Arduino" based ?

So quite a worn engine really hut it is years old.

Why did they go down this route when the engine had points ignition ?

Why not "transistorised" points ignition, it getter still, why not light or hall effect triggered cdi system.

There is room on the oe points base disc for either, requiring a different points cam/advancer unit, or utilising the oe "twin cammed" advancer unit.

You know of xl125r I think, that has the cdi system sensor with centrifugal advancer, cam shaft driving, which "looks" as if it may fit the camshaft sticky outy shaft ?

Where do all the dead machines go to on your small island ? I found your island in the atlas.

Perhaps if there is a breakers yard or collection point for "scrap" and dead machines on the island, you should spend some time there ?

Anyways, what's done is done.

Use the bike avoiding the bad vibration period.

Avoid using instant gasket. Banana boxes have a usefull sheet of useable relatively thick cardboard that I have used, and still do, to successfully make gaskets, that work well and contain oil.

Phone battery dying now so back tomorrow, a new day.
 

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Hi Ben, grey skies for you, it's raining 45 degree cats and dogs here today and after 20 minutes on the car I am cold and wet !

Do the cam sprocket bolts faul the alloy cam sprocket cover ?

It's a bit risky running the engine with that cover off as it controls cam shaft end float !

Since you are going to the expense of getting a new unused crankshaft, which I hope is in a wooden box or similar, get new cam sprocket and chain and the cam sprocket bolts.

How is the cam chain centre spreader, the large rubber wheel riding on the special bolt below the spark plug on the cylinder ?

It may be an idea to replace it anyway, along with the two rubber rollers/idlers/cam chain adjusters.

How is the
 

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Internet being a real pita again...i don't get this get this problem in emails
How is the rest of the cam chain adjusting mechanism, all good ?
You getting parts to restore points ignition ?

Research CMSNL for that thrust washer and peg spanner to remove the primary drive gear...

Back to the animals for me, back later....
 

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Coffee break and warm up....

The carb slide needle, top, middle or bottom groove for the little clip ?

You do have the air box/filters connected ?

Don't forget to check on CMSNL.com, you don't have to buy from them, the views are free to view.....

Also think about making a copper head gasket from sheet copper of a suitable thickness, not paper thin.....

As you know c90's have a copper ring head gasket and rubber seals.......
 

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Coffee break and warm up....

The carb slide needle, top, middle or bottom groove for the little clip ?

You do have the air box/filters connected ?

Don't forget to check on CMSNL.com, you don't have to buy from them, the views are free to view.....

Also think about making a copper head gasket from sheet copper of a suitable thickness, not paper thin.....

As you know c90's have a copper ring head gasket and rubber seals.......
 

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Discussion Starter · #40 ·
Hello there!

Back with more replies - thanks a lot for taking your time in walking me through this challenge.
I drove the bike more and now have 1000km's on the new pistons which means I can (should be able to) push it harder, which I tried. The bike really vibrates at any RPM over 6000 - it isn't something I can pass and then evens out at all. It is just there from 6-10K - haven't gone beyond 10 as it feels like it'll fall apart under me.

So to your questions. The carb part will be interesting, maybe I can tweak things there. I heard with twin (or more) carburateours that need to be synched manually, the problem can often be that one piston is better fed than the other and this causes all kinds of vibrations etc. I already adjusted both carb butterflies to slide exactly at the same time and also made sure both carbs have the air screw at the exactly same position. I took the carbs apart and cleaned them, the jets are identical in both of them. The headers warm up evenly - tested this by holding on both headers at the same time for as long as I could after a cold start and I had to let both go at the same time. I did not want to wait while smoke rises from my palms...
The sound from both exhausts are the same.

Ok again - to your questions now:

Looking at a picture of that thrust control ring, "washer" , it doesn't look very thick. I wonder how worn that is, or is it missing perhaps ?

I checked for any photos that I might have during disassembly that shows that ring and the answer is no :( But the idea is very good and I'll make sure to check for this when I have the new crankshaft with me for which I'll need to open the engine. The crankshaft I bought it used but it is "used in Japan by a Japanese rider" which will without a doubt be a 100 times better than what I have here. Here a bike is the transportation for the whole family and every day. I can imagine this bike was lugging 4-5 kids on dirt roads etc... In Japan they drive on the weekend and change oil regularely - this is of course a stereotype but as I lived in both countries for years, I think I can bet on this being the case.

End float looks a bit excessive to me.
Up and down play, radial play, again looks excessive to me.


I was afraid of this. Nothing I can do until the new crankshaft is with me - which will be next year.

Definite "wobble" in alternater rotor, damaged by a 3 leg puller ?, It something bent ?

I think this is just because the crankshaft is out of true. Remember it was opened (and I don't know how many times) then re-pressed. The sprocket on the crankshaft is also positioned wrong by a few millimeters which means I can't get TOP on the camshaft when the piston is in TDC - the top position would be in between two chain links. Nothing I could do except to bore a larger opening on the camshaft's sprocket and turn it slightly to allow for the camshaft to be in true TOP position. It isn't 100% accurate I am sure but a lot better than before. I explained this in my video - but not sure if what I said made sense or if my accent was understandable :)

One of the cam sprocket bolts looks odd and I cannot see the O mark.

O mark is there as you've by now seen it on my video. The bolts are just normal bolts as I can't get the special ones here - so I used a grinder to make the heads thinner. On this bike by the way the two bolts are of different sizes, this is so you can't put the sprocket on in the wrong orientation. Pretty simple but very smart! The bike uses a 360 degree crankshaft so I think even if the sprocket went on the other way nothing would happen.

One of the final drive chain sprocket bolts look odd also, which can cause a problem.

Those were replaced since. Now they are the original Japanese bolts with the "8" stamped on their heads. Got them in Japan.

Is the cdi unit "Arduino" based ?

I don't know. It is from a Suzuki Shogun 110cc bike. I tried looking for information on what this bike is called internationally but I can't find anything.
I just checked for arduino and I see it's some fancy programmable unit. This is definitely not one that can be programmed so it is stock and has a limiter from what I understand. I know nothing about it otherwise but bike seems to advance just find and won't advance beyond the point that is marked on the flywheel. Not sure above 4000RPM - haven't yet tried. Once I get a hold of a secondary cover and be able to do this through a little hole.

Slow Motion video being a good idea
Yup - figured this out on my own. I just use my iPhone's camera and there is a slow-motion option. When you open the camera up - you can scroll left and right to choose between modes - there's photo / video / timelapse / slowmo etc. This slowmotion works fantastic!

Do the cam sprocket bolts faul the alloy cam sprocket cover ?
Not they don't. I can't hear any noice or see any scratches on the cover.

It's a bit risky running the engine with that cover off as it controls cam shaft end float !
I had no idea it can move and even when I tried yanking it, the thing would not move! Wish the crankshaft was the same :). This head is from Japan by the way, the one that came with the bike was a total disaster. It was used so extensively that the hole for the shaft must have become worn to the point where the bike wouldn't start. If it starts, it will be used. Service is normally only seeked when bike isn't moving anymore.
So the previous (or before that) owner had bearings fitted on both ends of the camshaft and bored the head out to accomodate for this. The bore and the bearing isn't an exact match so the camshaft had a rather large play in the head. This is no longer a problem, I am using one I got from Japan and it is like new!

Since you are going to the expense of getting a new unused crankshaft, which I hope is in a wooden box or similar, get new cam sprocket and chain and the cam sprocket bolts.

Yes will buy all these parts on my next trip.

How is the cam chain centre spreader, the large rubber wheel riding on the special bolt below the spark plug on the cylinder ?

Already replaced it to a new one. The one that came with the bike was half the size :(. As long as it works.... :)

It may be an idea to replace it anyway, along with the two rubber rollers/idlers/cam chain adjusters.
One roller I've already replaced and the other one is sitting and waiting for me in Japan.

Research CMSNL for that thrust washer and peg spanner to remove the primary drive gear...
I did look and understand what you mean by that washer and the odd gear that drives the clutch basket.
I don't understand what you mean above - you suggest I remove it and inspect it - hence the need for a peg spanner?

The carb slide needle, top, middle or bottom groove for the little clip ?
As mentioned above - here I think there is still work I can do. Nothing about the crankshaft play I can quickly change so the meantime would like everything else to be sorted so when I install the new crankshaft - thing would just start being perfect :)
The carbs are aftermarket but do resemble the ones that were originally on the bike. These are for the Honda S90 otherwise - and aftermarket so not the original Keihin. They do work quite good I think. They ran just fine before I fitted the airfilters and now with filtration, they bog down at WOT. From idle to 90% throttle all feels well, engine doesn't overheat and plugs look good. However, when I smal the throttle all the way, the bike starts to hesitate and jerk.
I assume it has to do with the air not mathing the fuel being supplied - given that I restricted the airflow with the filters?
What do you suggest? I can play with the needle but which way I go in this case? I assume down - to restrict fuel to match the restricted air flow?

You do have the air box/filters connected ?
See above...

Copper Head Gasket
Will do this when I take the bike apart to replace the crankshaft. Now the engine is fully sealed with gaskets and additional threebond liquid sealant and for the first time I don't have leaks :) Very proud!
Opening the engine is rather hard as the sealant holds it together, don't want to do this too often.

Thanks again! Much appreciated.
Ben
 
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