Chaps
R/H exhaust and silencer on the twin port model 9 literally fell off yesterday. The hanger on the silencer had gone completely. I removed the exhuast silencer completely, and retrieved it by car after a noisy ride back home!
Questions - The exhaust nut also worked itself loose. How tight do these things need to be - as tight as possible? The exhaust is only held on by this nut and the feeble hanger/p-clip arrangement at the rear over the silencer. I was thinking of adding a further brace/strut at the lower end of the downpipe with a clamp and strut arrangement bolted to an engine nut for added strength. - thoughts welcome.
Forks - I noted that one of the large nuts on the lower bearing pin (5/8 I think) had also gone AWOL - yikes!
I also now note that these seem to need a washer - which I failed to note as when I pulled the forks apart, there were no washers. Firstly then - where can I get a nut? Secondly, how to prevent this happenning agin - fit a spring or shakeproof washer perhaps!
Hi!
You need to use a hook spanner (C-wrench) for fastening the exhaust nut. The connection to the silencer is sufficient for holding everything in place. An additional bolt somewhere is not needed and not period. The large nuts at the fork like to get lost, indeed. I solved this with some loctide and never had a problem with them anymore.
Cheers, Thomas
Thomas
Yes - I used a C spanner and gave the exhaust nut some extra torque using a ring spanner over the end of the spanner. The rear hanger arrangement seems pretty feeble to me and the exhaust does wobble about a little. The integrity of the system is not helped by the rigid rear end and the state of the roads. 3 points of fixing far better than two I feel. I'll have a think. I don't think it will too far out of place.
Fork link nuts - Yes I too thought of (blue) loctite which I think I will use. Apparently no washers were used originally.
Your exhaust wobbles? Maybe you should first try to get that in order. You can add an extra bolt, if you like, but that's not original. I mean, the roads some eighty years ago were worse than those today. Again, the two anchor points work for me and I believe for the majority here. BTW, all my fork link nuts have washers.
Thomas
The exhaust wobbles as there is effectively only one pretty flimsy restraint at the rear end of what is a fairly long and heavy assembly. It would not be so bad if the silencer fastened pretty much directly to the frame, but on mine at least, there is around 3" of thin section strut from the silencer up to the frame. This magnifies any lateral movement/vibration, and in my view is not conducive to providing any sort of rigidity to the exahust/silencer assembly. I don't believe adding a minor mod to the exhaust detracts too much from originality, and if the next owner doesn't like it, he can always remove it. Personally I would not like to risk another exhaust dropping away at speed.
I am not sure what your exhaust look like and it is your decision. Here's how it looks at my machine. It is fixed at the cylinder head and at the rear footrest.
This is the arrangement on both my 9A. The righthand side front silencer bracket acts as mount and silencer clamp and is bent backwards to attach to the lower front chainguard mount.The lefthand side is straight and mounts to the threaded lug on the frame.The last 2 pics are of my 90, both front silencer brackets are straight on these as that's where they fitted best.
Did you fit new sealing washers? These are collapsible, and apply a light load on tightening the nut. As John has described, the 1929-31 M90s had an additional bracket at the front of the pipe, as the catalogue pictures clearly show. They weren't fitted to the M9s or M8s, however.
P.
Interesting. My RH side is more like the arrangement as per singleminded, but with just the one (rearmost) P clip mount which was attached to the same lug with much the same vertical strut length. I may have to fashion another silencer mount further forwards perhaps. On Thomas's bike, the mount from the silencer seems integral/welded to it and the vertical strut element is far shorter, making for a much more rigid fixing.
Paul - yes crush copper washer was fitted. Nut was tighten up pretty tight!
you havn't said what year your bike is,,arrangements of brackets can be different.If you think you need more brackets, fit them , it's youre bike . What is believed to be standard may not be best.
The brackets on my bikes I made to match the 1932 9A parts list and the 1929 list in the '29 list is also a bracket to mount the pipe to the engine plates,many variations are possible.
I used 3/4" x 1/8" ( 20mm x 3mm) bright mild steel flat bar to make the brackets, the ones commercially available are not strong enough in my opinion.
If you look at the 1931 Parts List, the front bracket used on the 90s is catalogue number D429, factory number 5160A.
The 1929 parts list illustrates a very similar part (may even be identical!) cat no C313
P.
Hello Oggers;
I noticed that on jour bike the clutch is of the PULL type, that defines the bike as a 1932 bike, the only year the PULL clutch was used. My 1932 Model 9 is like yours.
I simply fasten the Exhaust nut with a C spanner and use a copper hammer to gently adjust.
Good luck.