1957 T110 English market import. Since I have only had this be for 3 yrs. I'm trying to familiarize myself with whats correct/incorrect while doing "routine" service and maint. One way to do this is as things go back together, ID each part, nut and bolt. That way you see whats there and whats not.
1. I am reinstalling the rocker boxes but have found there were lock washers under the rocker/head bolts. There are none shown in my parts book, therefore I do not reinstall those.
2. Found that all head bolts have 1 washer under each bolt head but none shown in parts book. Is there a possible reason someone has done this or is it done by mistake?
3. I also need to repair threads in the head for 1 rocker cover to head bolt. I have seen a previous post of somebody thanking somebody for the advice of 1/4X20 helicoil repair however I think the thread size in the head is 1/4X26 Are there thread repair kits for the 1/4X26 or by default (because there not available) do you have to use 1/4X20. If so, you also have to use 1/4X20 bolts that are the same length as the originals, Is this correct? Would you also use a helicoil close to to same length as the bore in the head? Any advice for installing helicoil before I get started?
So far the term routine does not apply to alot other than oil changes. Beware of anything discribed as routine.
1/4 x 26 bsf helicoils are available which I'm sure is the size. Some people think they are 1/4 x 26 CEI but I don't think so. They are almost identical, however.
As to washers under bolts, I note that for my 1967 there are supposed to be none under the barrel nuts but I have plain washers everywhere on the engine. It doesn"t seem right not to use them somehow. Dave
#108552 - 01/15/071:19 amRe: PARTS BOOK VS. WHATS ON BIKE
So your parts books doesn't show washers in the exploded view. One thing you will learn while viewing these parts books that sometimes there are other parts, such as washers, that don't appear in the exploded view but are listed in the parts book. So, look on page 34 of your 1957 parts book. You will see REF. No. 26 part number E3302-Washer, rocker box to cylinder head nut ( T110 and TR6) with alloy head quantity 6.
A lot of times if you don't see it in the exloded view, go to the page that diagram numbers point you to...in this case page 34 and look in the area of the associated parts for the rocker box fasteners and you will usually find what you need.
There are also parts listed by C.P. carton pack, which are located in the front of the parts book. Here for example, you will find the part numbers for the tach drive timing cover and components as well as pistons and rings, compression ratios , etc.
Bottom line: Don't assume that the exploded view diagram is 100% correct...or shows every sinchle part that you will need. Based upon common sense, one can conclude that a washer should be present for such an application and here we will be able to find it.
Many thanks Jon and Dave, I do agree with theconclusion that the washers should be there. Thats is partially what prompted the post. I think (sometimes) but your explanation of parts that aren't always shown is very helpful. Any suggestions as to length needed for helicoils ie. 1/2of the bolt thread, 2/3, 3/4.
#108554 - 01/15/073:33 amRe: PARTS BOOK VS. WHATS ON BIKE
Joined: Feb 2004 Posts: 1,956norbsa48503
BritBike Forum member
Whatever your part book says: Use a washer underneath any bolt head or nut when it touches aluminium. Damaged aluminium underneath the hexagon of a head bolt (no steel washer used) gave me problems as the hex was torqued correctly (as it chewed into the aluminium) but the bolt was not.
#108557 - 01/15/072:56 pmRe: PARTS BOOK VS. WHATS ON BIKE
Originally posted by cwicker: ... I think the thread size in the head is 1/4X26 Are there thread repair kits for the 1/4X26 or by default
The stainless stud I used to replace a missing rocker box stud on the T140 bobber was 1/4 20 on the end that went into the rocker box, and 1/4 28 (1/4 fine) on the end that sticks down through the head. So the helicoil would be course, but the nut on the other end of the stud would be fine.