2020-01-01_Motorcycle_Trader

more detail on Roothy’s
exhaust projects for the
bikes and jetting changes
necessary. Is he going
into business or selling
the design to someone?
MT is a great mag and
has been so since way
back when (and I mean
way back when!)
Graeme Templeton
[email protected]

If you’re as old as you
suggest, Graeme, you’ve
probably heard your
fair share of differential
whines in a variety of
older cars. It was an
inevitable part of the
symphony of driving
old Holdens, Fords and
Zephyrs. They all had
legitimate diffs: designed
to allow two rear wheels
to travel at different
speeds.
BMW calls its ‘diff’ a
rear bevel drive, which is
probably a more accurate
description and it doesn’t
work as hard as car diffs.
The ‘hint of whine’
you’re hearing is wear on
the gears. It isn’t common
on BMWs but if the rear
bevel drive oil level
has dropped (leaking
seals) or the oil hasn’t
been changed as per the
factory recommendation,
wear will occur.
BMW recommends a
major service for your
model every 15,000km
or every 12 months.
This service includes
changing the rear bevel
drive oil. The drive
pinion and crownwheel
sit in a housing that holds
350cc of, usually, an
80W90 hypoid gear oil.
Most people understand
the change period when
it relates to distance

but can be neglectful

when it comes to time,

particularly on bikes

they don’t ride regularly.

If you let the oil sit for

a long period of time, it

settles. Any moisture

in the closed area then

starts eating away at the

metal. It’s another case of

‘use it or lose it’.

Since you’re only hearing

the hint of a whine, I’d

change the oil and keep

riding, but I’d make

sure I change it every 12

months from now on.

The noise probably won’t

get any louder but if it

gets progressively worse,

you’re looking at a new

pinion and crownwheel.

My guess is it won’t get

worse and the bevel drive

will outlive you.

MOTORCYCLE TRADER 91

Yo u’r e a bit spoilt having

a Himalayan as well.

Alternative sparkplugs

include NGK’s CR8E and

Champion’s RG63.

In theory, what Roothy

does with his exhausts

shouldn’t work but

always seems to. I’ve just

spent 2000km with him

on his R 100 LT with his

own custom pipes that

I could feel pulses from

while I was 50 yards

behind him. I’ll get onto

him to write a yarn on

Rooth-theory exhausts.

GUIDO SEALS

THE DEAL

I’m in sunny Marla,

which is in northern SA

and I have a sick BMW

so would appreciate your

advice.

It struggles to rev much

past 4000rpm, which

gives me a top speed of

about 110km/h so it’s

going to be a long trip

back to Melbourne.

It’s also guzzling fuel –

around 10km/L. It starts

easily and runs sweetly

at low revs. It’s been

sitting in a shed for the

last couple of years.

Since leaving Alice

Springs, it’s had several

hundred kilometres of

fresh fuel and injector

cleaner through it. The

carb bowls and main jets

are clean, and the fuel

flow seems ample.

I can’t get the

sparkplugs out at the

moment as the spanner in

the toolkit is the wrong

size, but they seem to be

the correct plugs.

TS VERSUS ER

In reference to your recent discussion on the difference between the Suzuki

TS185 and the ER 185 from the same manufacturer, if you check both engine

and frame numbers, I’m sure you’ll find they both start with ‘TS185’.

The ER models started after the M model, which had an orange tank.

NZ models had ER on the seat.

Dave Myall

[email protected]

Thanks for this, Dave. We’d established the TS and ER were essentially the same

bike and the engine and frame prefixes prove this. Having said that, if you line

up an early TS with the later ER, they certainly look like different bikes.

How fortunate were those among us who lived through the two-stroke

period of bike history? The TS185 became a legend and substantially outsold its

TS200R and TS250X siblings. I wish I still had one.

The TS185

became

a legend

and

substantially

outsold its

TS200R and

TS250X siblings