well the other day I was coming back from a ride on my RGS when it gets to about 65 mph there is a banging rattling sound
turned off on to a miner road and keep it at about 40 mph to get me back home but as soon as I open up to 60 - 65 it cam back....did not sound good at all..... so just striped the primary side down can`t find anything wrong there so took the timing side off as I just had my Dynamo sorted so wondered if I done something wrong in there.....but No everything is fine.
so any suggestions as to what it could be please as I still have it striped down ....... just hope its not an engine out Job.
Cheers Mo
Difficult to say really but before stripping anything down I would normally use a mechanics stethascope to gve me a general idea as to where the noise is coming from you can use a long screwdriver just put the tip to various parts of the engine top end bottom end primary and timing sides and the handle to your ear this does help in identifying where the problem lies. But if you have already stripped the primary down I presume you have stripped the clutch down to eradicate that , if you have just removed the cases and done a visual inspection then replace them and try the screwdriver test first. you could before replacing the cases see if there is any play on any of the moving parts and shafts. failing that it does seem to point to an internal problem and an engine strip down good luck. hope t is nothing to serious.
Hi Mo,
So no noise at 40 but noise at 60. Did the noise suddenly start or did it gradually come in? Did it still sound the same at constant speed or was it more when under load when accelerating? Is it speed related or revs related?
Dave.
If you still have the timing cover off try levering the crank up and down. Use something like a tyre lever under the timing pinion. When this suddenly occurred on my Shooting Star in was the bronze bush. I had about 20 thou play. Also a very simple thing that might have occurred check the cylinder base nuts. If they come loose the cylinder goes up and down and makes a horrible sound like big ends failing. If left it will cause the barrel to fracture across the flange.
Hi,
Good thinking about the cylinder base buts. This did happen to me once.
Just another thought. If the timing has slipped that could cause some noise and vibration at higher revs. This was the case with an A10 at the UK Inter. that felt like the bottom end was about to blow up when under load pulling off and at higher revs. No problem with the bearings but timing, I think, retarded and/or auto advance not working properly.
Dave.
I had a similar problem with my Super Rocket. Very worrying noise! So limped home at 30mph.
Turned out to be centre stand rattling in frame!
So double check it is an engine issue.
The fuel tank can also make quite a noise if it starts to resonate and is not properly secured on firm rubber pads.
Hi everyone thanks for you comments,
I have just striped off the rocker Box and the head and all were fine so then went a took the barrels off and the were great the pistons did not have any marks on them at all. took the bottom crank case plate off and found bits of some sort of steel in the strainer, also when I took the pistons down to there lowest stroke I found the pistons and made witness marks on the flywheel
even as I was holding them as upright as I can without the barrels when they came to that lowest point they hit that Flywheel....very strange.....the pistons are still on at the minute so have not looked at the inside to see who made them, and all they is on the tops is the mark 71.....so I was told they were 8,5:1 but thats all I know about them, so I assume that 71 means 71 mm but thats it so No +20 or +40
Hi Mo,
71mm is very close to 0.040 oversize and is common on pistons. Usually rebore is done to match the pistons so there should be no problem there. For the piston skirt to make contact with the flywheel indicates massive clearance in the big ends or the rods are out of shape. Do the pistons.rods move up and down a lot? Have both pistons marked the flywheel? Although you are gong to strip the engine completely, check the bits from the strainer with a magnet to determine if ferrous or not. This is quite intriguing.
Can you post some pictures?
Dave.
Hi dave
There is No movement at all in the pistons on the rods or the big ends... they are Gpm pistons which I have done a search for and found they are made in Italy or so it said..... the metal that was in the strainer was indeed steel and looks like a shim.... I have been told to take a few Thou of the skirt of the pistons as was told the bottom end is fin and Not to stirp it.... I took one piston off the rod and check it and it has only been just marking it a bit.....( well I here you say it should not even hit any at all ) so I will take a few thou as they say off and put it all back together in the next week or so and let you all Know how I got on....so fingers crossed :-*
cheers mo
Hi Mo,
Make sure you remove exactly the same from the each piston and from each side to maintain the balance.
If it looks like shim material then this could explain why it started quite suddenly as the shim will throw out once it fails. Is there a lot of end float?
Dave.
Hi Dave
Yes I have removed about 15 tho or so off the bottom of both the skirts on the Pistons and I have also made that weight of both the pistons are the same at 278 Grams each and both flat on the bottoms too, I have put them back on the conrods and they both Now don`t touch the flywheel when at there lowest point..... so Now I have done that I can Now get on with all the clean up of all the parts and even respray the barrels and hope to put it back together in about a week or so and will give all you Guy`s an update as to what the out come will be...so Fingers Crossed and everything else ;D
Cheers Mo
Hi,
Did you check the end float to see if a shim has been thrown out?
Dave.
Anymore then 3 thou end float will hammer the bronze timing side bush.
Hi yes there is very little and I mean little end float so that all seems to be good.
Good morning,
Good news about the end float. So looks like problem solved. Good lick with it.
Dave.
Hi everyone
I am still in the thinking of do I do a complete strip down......as I am still not sure as to why them pistons were hitting on the flywheel after 2,300 miles after it had a rebuild before I got her...........do anyone think it is wise to strip it right down ?
Mo
Hi Mo,
The horns of a dilemma I think. The piston contact, which must have been there from the rebuild if there is no movement in the bearings and journals, is sorted. So one option is to put it all back and ride it to see if it is all OK. If no noise then ignore the bits of metal in the sump and problem solved.
If there is still a noise then a strip down will be needed and where did those bits of metal come from. If it was shim then it would be obvious and there would be more end float. If not a shim then what?
Option two is strip it down and avoid the risk of doing serious damage if something fails.
I would go for option two as you have already stripped some parts off already.
Dave.
Hi Dave
Well I have convinced myself to go for option two..... as I want to find out what them bits were from if anywhere that is, unless someone was not careful in putting it back together and dropped some bits in when the barrels were off and something went in at some point.....anyway I think I will be more happy when I take it to bits to find out.....funny thing is I have had to do this to all my bikes when I have got them...which is to strip the engines and rebuild them at least I Know what has been done to them if you Know what I mean, thanks for all the help and in due course I will let you all know my findings ;D
Cheers
Mo
Hi everyone
well here is an update..... I have taken the engine out and today split the crank cases did not find a thing of where the peace's come from that looked like shim,
but the primary side bearing outer came out without even having to heat the case up....also the inner part of the Bearing on the crank also I can put on and off by hand.....this is all a bit worrying as not had that before :-[
so any Ideas of what to do about that as I Know that is Not right........next job is to take the pinion off the oil pump side and have a look at the bush.........all seems Not good and it was meant to be put together by a gold star engine Specialist ;D
Hi,
If the primary bearing fell out on its own then it could be more of a problem but if it still needed a bit of a tap or push then a good bearing retainer should sort that out. The inner race on the crank could also be secured in the same way but if too easy to put on and off then the crank can be knurled a bit to tighten the fit and bearing retainer also used. What make is the bearing? There are some dodgy un-branded ones out there so replace it with a good one like RHP.
Dave.
as Dave says, check bearing make. I rebuilt a square 4 engine for a customer, he suplied the bearings he sourced from an Ariel specialist.
cases heated up old outer fell out, dropped the new one in and left to cool. on turning the case over the bearing fell out. RHP, Timken, SKF are my main choice at a push Koyo (oem for Japanese superbikes).
the main thing is C 3 class of fit, tighter tolerances. the ones for the square 4 were chinese and .003thou under size on outside diameter.
well just had a look at the Bearing and it`s a NTN NF 206E
But I will be replacing it for sure....oh also the cage the rollers are in is Plastic which I would rather it be steel or Brass..
So what is the best Bearing to use and what's the Numbers on it ? as I can check them out at my local Bearing dealer... oh I will be using Bearing Lock also dot punch the out race a bit as well as the Bearing Lock.....and someone said to dot punch the Crank Journal then put on the bearing with Bearing lock on it too.
How's every one think of that....?
Cheers Mo
Hi Mo,
I have dug out an old RHP bearing and the number on it is NF206CN. CN denoting standard clearance. Some say use C3 as this can expand a bit more. I am not certain if the original BSA spec was CN or C3 but I suspect either will be acceptable.
Dave.
Hi Dave
yes I did have that said to me today at the bearing company and they said they can get RHP or NSK. But what do you think about the dot punching to the crack to just take up a bit along with the Bearing lock which I got today ?
sorry to ask but do you know anyone that I can get a long split cone collet to replace to one that had Cracked in half as I
have tried loads of places and can`t seem to get one>
Cheers Mo
Hi,
Dot punching the journal can work but it needs to be even or the bearing could be ever so slightly eccentric and the journal is hard.
Which split cone collet are you referring to?
Dave.
its the valve collet Dave ..sorry
Morning,
Try C and D Autos 01564 795000 or email canddautos@gmx.co.uk Probably best to ring them up. They did have all the valve parts for RR and SR a few years ago and they carry a lot of NOS.
Dave.
Hi,
Is this the one you are looking for? SRM currently have 6 in stock. If one has split it may be worth replacing all of them.
Dave.
Hi Dave
Just had a look at the SRM site and I think they look like the small type where the ones I am looking for are the longer type so I Might give them at C and D Autos a try....all the others I have had out and check to see if they were ok along with just grinding in the Valves at the same time.
cheers Mo
Hi,
OK. Can you post a photo of the one you are after as I may have a few spare.
Dave.
Hi dave
if you have got any that would be great thanks, also a picture where the pistons hit the flywheel..
Mo
Hi Mo,
The pistons were just 'kissing' the crank. I have some standard collets rather than the SR ones
I think the SR/RGS collets only come in one size and it could be a bit of distortion in the SRM image. The one in you photo is the same as the ones I got from C and Ds. Either way call them for clarification.
Dave.
well i forgot to give the size :o
I have just gone and done that Now...sorry in metric ;D
it is 11.77 long if that any help
Mo.
oh also now been said that my cases are a mess....well they have a had a lot of Heli coils put in and some badly..... I Know a bloke he has offered a set of cases for £150 but don`t know what to say to that as don`t know if that is a good price or Not :'(
Hi,
The 11.77mm looks about right for the ones I got from C and Ds.
As for the cases for £150, then it depends on how good they are. If they are in good clean condition then that is not a bad price but if they are not much better than the ones you have then it may be best to sort the ones you have.
Have a really good look at them and compare them to yours. Check all the threads and joint faces. Look to see if bearings have been loose and/or rotating in the case. If you are happy with them offer him a bit less.
Dave
thanks Dave
he said they are really good ones with no threads Knackered and they have been blasted so I will check them out as for the Collets I will give them a ring to see what they say.
Mo.
Good morning,
If they are really good then it will probably be worth getting getting them but hang on to your original RGS cases. At some point it will be worth getting them sorted out so that you can keep the original RGS engine number.
Dave.
If I were you I would find someone that can refurbish you original cases and rebuild it as original . you will spend a lot of money building up your engine with cases that are not your original cases . There will be people that can make them like new .
Hi Dave
it is a rep so not to worried about the Numbers but yes I will keep them....oh just got off the phone with Ian at C&D Autos lovely guy`s and got me collets on way Monday I did say about you put me on to them so he thanks you too.
I will keep you up to date with what I get done.
Thanks again
Mo.
Hello all.
Well an update on the rebuild or lack of it at the moment, I got them casing and they are really good but now comes a problem, I took my Crank Bush out of the old casings and put in the new ones I got put new shells on and cleaned the sludge out Not as if there was much in there after only 2,300 but done it as a matter of course, put the two half's together and one of the Big end bolts is hitting on the inside of the casing on the pump side can`t see why that is the left is fine any ides this build is being a bit of a nightmare :-X
Cheers Mo
Hi Mo,
Did you replace the big end bolts and nuts? It is always a good idea as they have been stressed when torqued and could fail if used again. Some will argue that it is OK to reuse but I would not.
It is possible for a big end nut to touch the case if you rotate the crank and allow the rods to go too much from centre. If you hold the small ends central to the cases as the pistons would hold them and you turn the crank does it still catch?
Dave.
Hi Dave
No I did Not replace them as I was told they would be ok to use again...But I like you dont want to be doing this job again so I have just ordered a new set of Bolts and Nut from D/F today.
also got told if I put the pistons on with the barrels then check to see .... as they might not hit as you say they are close anyway,
Mo
Hi Mo,
Rather than fit the pistons and cylinders just hold the small ends central so that they in affect go up and down vertically as they would in the engine. Nothing will touch unless there is a problem but as you are going to replace the big end bolts and nuts you will see exactly what has been touching.
Dave.
Hi Dave
yes I also think might be the case that the bolts might have stretched some along the way as might have been used a few times but I am Not taken any chances as we said replace with new to be sure, so when they get here I will indeed retry everything before I fit it all back together.
Mo.
well we back
Good News the bolts and nut turned up yesterday and I put the bottom end back together and yes No hitting the cases so it must have been the bolts and Nut`s the problem so hope Now I can get on with the rest of the build.
Thanks all Mo
Hi Mo
Might be a bit late now but please dont use a centre punch on the bearing housing to retain the bearing, its a practice from way back before chemical adhesives , Loctite, were available.
With the correct grade of loctite it is possible to reclaim a bearing housing with as much as 0.010" clearance under certain circumstances.
Punching the cases with a centre punch will just cause further damage and is most unlikely to be effective.
Regarding the metal found in the engine there is no way I would be putting that engine back together until I had found out where it came from and how it escaped from where it should be.
Good luck with the rebuild.
Hi John.....yes I have put it back together and no I used the High strength Loctite an it has been fine and worked a treat, But thanks for the warning... as to where that metal bits came from hell knows as there is no way it came from anything in the bottom end.....unless who put the engine together had something drop in when the still had the barrels or head off.....as I am very clean around my work area when doing a rebuild so there will not be anything going in where it should Not be.
cheers Mo
Just seen this have you checked the shims between the drive side bearing and crankshaft as when these break up they leave slithers of steel in the bottom. :-[
Hi Yes that was one of the first things I checked and the two that were there were all fine.... but a good thing to point out tho.
cheers Mo
Seen it to many times in my A7SS. Like yours my bearing is a little loose on the crank and it would move ever so slightly,pinch and then tear the shims up.
As Jim has mentioned about the tank being a possible source I also have found this to be true. My B33 sounded like a clothes dryer running a full load of loose ball bearings BUT only when the bike was in motion and only in the higher revs. Turned out it was the Gas tank. The sleeve in the frame that contains the nut & bolt at the Gas TAnk ears was the culprit. I made a new tigher fitting sleeve and also improved the all the rubber mounting points so no way the tank can rattle. Just a thought but perhaps double check that there are no metal parts of the tank touching or close to touching the frame.
I mention this as you have stated the noise is at certain speeds, I am guessing if the noise is not heard when reving in neutral you may have a similar problem to mine and Jim's.....wayne