The '97 engine repair

See the pictures
Why did I open the engine?
Tools you will need
What I found out
Reassembling the engine


If you decide to open an engine, you should know, what you´re doing, and you should know about basics like how to properly adjust valves timing. If you´re not sure, better ask a qualified mechanic. Also, I do my very best to tell the correct things, but of course I can't give any warranty!

Why did I open the engine?

It began during the ´97 summer holiday in Sweden: An occasionally audible slight clankering noise, when the engine was cold. As soon as the engine got warmer, first after some hundred meters, the noise disappeared. However - during the months the noise got louder and louder, and the time befor it disappeared, got longer and longer. At last it was very loud and it took up to 6-7 km to disappear. I suspected at least one worn out camshaft chain. Also I noticed a very high oil consumption (> 1 ltr/1,000 km), so in November I decided to disassemble the engine. First I´ve been about to write a complete "howto disassemble a TA engine", but this would be a huge document, and it is described in any maintenance book. So I decided to confine to some special hints you probably will find nowhere else, and better tell you of what I found inside my engine.

This is my second engine - the first is standing in my garage. It still runs, just the oil consumption after exactly 100,000 km made me think of disassembling it in ´95. But then I found this engine - with 38,000 km on it, and together with a carb set and a rear shock, I gave DEM 750.- for it. So I thought, that it would be a good idea, just to change the engines, and the other time to overhaul the original engine. The first thing I did, the second one I did not. And now, after this engine has also run 91,000 km all in all, it´s time again to do something.

Tools you will need


When being about to pull the engine out of the frame, be sure not to put your bike on any kind of stand, neither a centerstand nor any other bike stand. Put it on a suitable chest - I used a mineral water chest. Why that? Simply, because the engine is lying safely on the chest, once you have losen all the connections to the frame, and because it´s much easier to get it out of the frame now.

Before losening the engine-frame connections, remove the following things:

Now you can losen all the 5 connections between the engine and the frame. Once you´ve done so, lift up the engine on the front side, using a big screwdriver between the engine and the chest, and turn the engine counterclockwise by 90 degrees, so that the front cylinder is pointing to the left side. Now you easily can topple the engine out of the frame, front cylinder first. It´s a good idea to have a second suitable chest standing on the left side of the bike to rest the engine on it. Attention, the engine is heavy! If you´re not sure, if you can handle 60 kg, ask a buddy to help you.

When being about to replace the cam chains, you have to dismount the generator´s rotor and the clutch. For dismounting the rotor, you´ll need an engine blocking tool and a special pulling-off tool with a M22*1.5 mm thread. If lacking a blocking tool, you may put a piece of cloth between the gearwheels on the clutch side. When losening the screw holding the rotor on the crankshaft, please note, that it´s left-threaded.
When losening the 24 mm screw fixing the clutch on the crankshaft (right-threaded), be sure not to block the gear at the clutch basket, but better via the sprocket with a gear engaged. I´m lucky enough to have a frame fragment (the guy I bought the second engine from, gave it to me), so it´s easy to block it. Or you may remount the springs without the clutch plate, using suitable disks between the springs and the bolts, and then block the engine with a piece of cloth as described above.

What I found

At this state I found, that both the cam chains were worn, but that the reason for the noise has been another chain: the one driving the oil pump. You´ll find it when removing the clutch cover and the clutch itself. I could find traces of touching the housing on both the chain and the housing.

When having disassembled the engine, of course you should look after all the other important things: cylinderheads, camshafts, valves, pistons, cylinders and so on. I saw no need to disassemble the engine completely, so I confined to check the things I could reach.

measured (mm)worn when (mm)remark
side play of rods against the crankshaft< 0.10.3ok
diameter of cylinder bore7575.12ok
diameter of pistons       ok
piston bolts and piston bolt bearings:        
cylinderheads spoilt?< 0.050.1ok
valve seats1.5> 1.5hmm -decided to consider it ok ;-)
inlet valve shaft diameterall ~5.35.45replace
exhaust valve shaft diameterall ~6.46.55replace
camshaft bearings22-22.121.9ok
height of exhaust cams3837.9ok
height of inlet cams38.238ok
bore of exhaust rockersall 12.112.05actually, they are worn. But since the contact surfaces are ok, I decided to remount them
rockers´ axles (diameter)11.85-11.911.83ok

The adjusting screws of both the exhaust rockers showed pitting, so they were replaced.

Outlet valves and seats were slightly burned, but besides that, seats seemed to be ok. They have been smoothed. Input seats were ok.

The pistons were wearing nice little black coke caps - an aftereffect of the high oil consumption, caused normally by worn out piston rings and valve seals. The piston rings I did not check, they simply were replaced ...
Also replaced: both the cam chains and the oilpump chain. And, of course, all gaskets.

Cam chain tensioners and guides seemed to be ok, so they are remounted.

Parts´ prices

Prices are for 1 piece, in DEM, without VAT and as of NOV-97.
Find a universal currency converter here

2camshaft chain14401-MM9-003159.-328.-
2alternatively: aftermarket cam chain by Detlev Louis1004752682.- (incl.VAT)164.- (incl. VAT) *
2camshaft chain tensioner14510-MM-000120.-240.- **
2camshaft chain guide14522-MM9-00034.5169.02 **
1oilpump chain15136-MF5-01333.9333.93
2exhaust valve14721-MF5-01059.02118.04
4inlet valve14711-MV1-00028.26113.04
2valve adjusting screw90014-MF5-0004.869.72
4valve seals for inlet valves12208-413-003    
2valve seals for exhaust valves12209-413-003  57.40 (all 6 seals together)
2set of piston rings13011-MS6-30562.17124.34
2cylinder foot gasket12191-MM9-8508.5417.08
2cylinder head gasket12251-MM9-85140.6981.38
1gasket for clutch cover11394-MM9-85019.2519.25
1gasket for generator cover11395-MM9-85013.9013.90
2O-ring (cooling liquid pipe -> cylinder)91315-ME9-0033.917.82
 div. copper seal rings  7.107.10
1fairing nut90111-MM9-0007.177.17

* took this instead. But attention! The ´97 Detlev Louis catalogue offers two chains:
1. part# 10047509, DEM 85.-, for ´86-´87 Transalp (Seen it? There never were a TA in 1986...)
2. part# 10047526, DEM 82.-, for ´88-´93 Transalp
If you have an ´88 TA, you have to take the first chain (10047509), the other one is too small.
** not needed

Reassembling the engine

Before reassembling your engine, carefully remove all remnants of old gaskets. Use a special scraper for this, don´t use a knife or a screwdriver, else you will destroy the surfaces. Oil all gaskets before using, else they will leak.

Piston rings are mounted in following order:

Note, that marks on the light and dark grey rings (f.e. a ´N´ for standard size rings) have to point up, towards the piston´s top.

When remounting valve springs, the narrow windings must point down (towards the cylinderhead)

Be sure to mount the fixed cam chain guides before mounting the cylinder head! The cam chain tensioners can be mounted, if cylinderhead is already fixed. Cam chain tensioners have to be released before mounting. To do so, push the wedge and secure it with a small nail. You don´t really need to take off the spring, as to be seen on the picture, pushing the wedge is a little bit easier. Just don´t forget to remount the spring!

Don´t mix up the camshafts! Before mounting the camshafts, grease all bearings with MoS2 grease. Use Loctite, when fixing the sprocket to the camshaft.

When fixing the cylinderhead, tighten all screws in prescribed order and with prescribed torque (see below).


It´s not so important, to tighten screws with a tenth of Nm (Newtonmeter) torque, but it´s important, to tighten a set of screws with the same torque. For example, the cylinderhead screws #1-4 you may tighten with any torque between 35-45 Nm, but all with the same torque.
Number of screws is for one cylinder!

 numberthread diameter (mm)torque (Nm)remarks
cylinderhead screws        
nut 1-441035-45  
nut 51820-25  
bolt 6-72820-25  
bolt 8 (Allen head (Inbus))168-12  
holder: bolts3820-25  
holder: nut1820-25  
holder: bolts268-12  
sprocket: bolts2720-25use Loctite
primary gearwheel: bolt11280-100  
clutch hub nut11880-100secure by hitting the secure sheet
clutch operational sheet (or whatever that is called ...): bolts468-12  
oil pump sprocket holder: bolt1613-17use Loctite
rotor bolt112100-120left threaded!

all coloured:
Detlev Müller
all b&w: from "Reparaturanleitung Honda XL600V" by Bucheli Verlag, Zürich

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