Long Engine Warm Up ‘55-‘69

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Long Engine Warm Up ‘55-‘69

Post by ferrarirobinson »

I have heard from lots of places and people that the ‘55 -‘69 model engines take a long time to warm up. And my ‘57 R60 certainly does take a while to run smoothly. A good while. Of course air temperature determines length of satisfactory smooth running but even 70° and above require a longer warmup period that I think it should be. Is the reputation warranted or to much of a generality. Or, maybe it’s Model specific. Or maybe it’s not true.

If true, what causes this condition. Head design ? Carburetors ? Both ? Am I not holding my tongue correctly during kickstarting and after it fires up .

What’s your opinion ?


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Re: Long Engine Warm Up ‘55-‘69

Post by FL54 »

My ‘63 R50 is definitely cold blooded. It takes several miles for it to warm up and smooth out. I just accept it as the nature of the beast.
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Re: Long Engine Warm Up ‘55-‘69

Post by Daves79x »

My '59 R50 starts instantly with minimal tickling/no choke and you can ride it off immediately. I raised the metering needles one hole in the carbs. For sure not cold-blooded and does not run rich either - plug color is perfect.


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Re: Long Engine Warm Up ‘55-‘69

Post by wa1nca »

Yes move the slide needle down to #3 position one hole up from the bottom hole and check that the idle jet is correct size
Note: Like any engine it is not a good to start and drive without some warmup
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Re: Long Engine Warm Up ‘55-‘69

Post by skyler.robbins »

Mine is cold blooded... I let it idle for a couple minutes while getting my helmet on and such.. and it takes a couple miles of driving before it's happy.

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Re: Long Engine Warm Up ‘55-‘69

Post by miller6997 »

I live in a warm climate where it almost never drops below freezing. My R69S is ready to go in a couple of minutes. I start it, and by the time I've put on my gear I can be on my way with little or no stumbling.
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Re: Long Engine Warm Up ‘55-‘69

Post by 312Icarus »

Consider this...you have a pretty massive (thermally) engine system in toto: case/crank cams/jugs/oil etc all of which start at ambient. Gasoline vaporize better as it gets warmer (until such time as it boils!). In order for that gasoline to vaporize the entire thermal mass must get warm enough to allow fuel to vaporize at a rate that it will support the load, without artificially enriching the mixture (choke) Net mixture ratio change significantly with temp, one of the major reasons you don’t see any air cooled cars out there any more. Keeping air cooled engines at constant temps to allow proper lean (read clean) fuel air mixes is near impossible.

So with the vintage boxers (and singles for that matter) the heads and the full intake system needs to get warm. On a cold day, from a cold start getting the heads warm can take a good long while. A short ride at gentle throttle (once the oil is a bit warm) is probably the best way to warm up an engine like this.

If you engine starts we’ll, and gives full power nearly cold, I would guess that it is running too rich once it is fully warm. Plugs can tell that to an extent, as can a exhaust gas temp check...not something that most of us can do.


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Re: Long Engine Warm Up ‘55-‘69

Post by JamesKnt »

In my opinion, it is the model of the bike as some bikes take quickest to warm up the engine than the others do. Have you checked the conditions of your carb?

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Re: Long Engine Warm Up ‘55-‘69

Post by dosgatos »

My 1967 R60/2 has all standard settings and jetting for the carbs. Cold starts involve flooding both carbs, kicking through twice with half throttle and ignition off, then with one kick it will start. It will then idle and accelerate perfectly. After riding it will usually start on the first kick. Plug color is a nice light brown. My only complaint is that it will backfire through the left carb occasionally at idle, but then the carbs are 55 years old!

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Re: Long Engine Warm Up ‘55-‘69

Post by Flx48 »

"I have heard from lots of places and people that the ‘55 -‘69 model engines take a long time to warm up. And my ‘57 R60 certainly does take a while to run smoothly. A good while."

So Charlie, recognize anecdotal information for what it is: anecdotal; you had one good reference point there: your own experience.
And now several more were been added from members responding to your quest for their experiences.

I think it's also important to put your question in context.
When these bikes were current, many folks were drawn to them as an alternative to the Brit offerings of the day, which at the time had broad appeal similar to that enjoyed by Japanese bikes today.
The jacket on English bikes was they were great rides, with all the power and handling, but in need of constant upkeep.
While the rep with the BMW at the time was one of perhaps a more elegant if sedate ride, but needing little in the way of maintenance.
The truth on both was somewhere in-between.
The BMW did require comparatively less maintenance, but certainly not no maintenance.
I grew up next to a one-man BMW dealership/mechanic shop, and he had two distinct groups of clienteles, one group made up of the doctor/lawyer/professional types who brought their machines in methodically for regular service; the other (perhaps larger) group were those who limped in only when they had problems.
When I got my first BMW at 19 or 20, I fell into the second group; never had funds, just wanted to ride, and allowed myself to remain ignorant of the consequences for far too long.
So what I saw was many (like myself) who ignored the owner's manual recommendations.
My old owner's manual (same one as yours) says some interesting things, like: remove, dismantle, clean, refit, and readjust the carbs every 4k miles.
Not many did that back then, I know I didn't. (any guesses on how many follow those recommendations now, even with the E10?)
Many rode rode till something broke, and then addressed it.

"Or, maybe it’s Model specific."
Well, the S models were sport models because they had higher compression, greater valve overlap, larger diameter carb venturis.
Being a bit more high-strung also meant being a bit more susceptible to anything being out of whack.
For example, those larger throats meant that the air passing through the carb moved at a slower speed during idle than with the smaller carbs, so if the idle tuning was not spot on then good atomization was not either, and both the idling and the ability to move off idle to the main circuit would suffer.

So my answer to your question is- it depends.
There were (and are) the bikes that followed recommended protocol, and are quite capable of the manual's 3-4 second tickle to cold start and go consistently; there's the bikes blessed with the same good design but cursed with inadequate maintenance; and bikes in between with every manner of condition.
All were observed and experienced by a wide range of people drawing a wide range of conclusions.
That the /2 reputation has endured intact with such a strong following this many years on, tells me that overall there was more observation and conclusion drawn from the good examples; while the bad examples were largely recognized for what they were- bad examples.

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