Banging on about throttlebodies......

Yes, I know I do it but I'm just trying to save people heartache.

Over the last couple of days while we had a quiet few hours I got Michael to fit my 'Spare' set of TB's to the yellow bike. After it's drama with the blown out spacer gasket and knackered big ends I decided to give it a birthday and fit the brand new set I'd bought for 'Later'.

Why? Well it's had a pretty rough life the motor in this bike. After the flat tappet fiasco did for my first motor I slipped in the entire motive unit from a crashed 2012 wreck I'd bought. The exact mileage on the unit was unknown as the dashboard was smashed but it was certainly low, I'd guess sub 20,000 km. I'd already had issues with my original TB's so the set off the wreck went on at the same time as the motor swap. Since then  the bike has done a load more Kms including some where I'd missed that the airbox drain hoses, whilst still attached, had fractured out of sight allowing the ingress of grime. Not a lot of grime. But enough.

Now the damage wasn't extreme. Indeed examining the old TB's once off the bike showed very little wear. Barely detectable movement in the LH butterfly spindle, pretty much unmarked chokes in the TB's themselves. But the bike didn't feel *Right*. It didn't display any of the serious issues associated with badly worn TB's. It didn't 'Chuff' and spit back at idle or have poor low speed behaviour but it never felt *Right* and it vibrated more than most other 8V's. It also had the persistent and seemingly unfixable 1400 rpm idle which despite Mark's best efforts we hadn't been able to cure.

Since I think it unlikely I'll do enough Kms to wear out another set of TB's before I croak or get too old to manage GRiSO I decided to fling on the new set. The old ones can go on the shelf as my *Spare* set. They aren't awful but they aren't good either.

So did it make a difference? YES!, it's awesome. Idle is rock steady at 1,200 rpm, throttle, especially ar tiny openings, is utterly predictable and linear. Everything is smoother throughout the rev range and it pulls harder than ever, especially in the all important midrange.

Why am I banging on about it? Simply because it once again shows how VITAL it is to look after your TB's, especially on the 50mm TB models. Make sure you use a proper pleated paper air filter and it is fitted correctly, check all your drain and breather hoses regularly for both attachment, fractures and ensure they are plugged, don't over-fill your sump with oil, (And anywhere above halfway between the marks on the stick is too much!) and every 20-25,000kms actually take your TB's off and clean them thoroughly with 'Sensor safe' throttlebody cleaner.

New TB's come in at a cool $2K Australian and who knows how long they are going to be available? I've yet to be able to find anyone who refurbishes them. Look after them. The enjoyment of your bike depends on them!

Very interesting and useful! Thanks!

AF1 shows that they have a “fuel injector” cleaning service for $25 per injector. Then it lists the bikes they can do. It has a lot of Aprilia and MG but doesn’t list the GRiSO. Has the Stelvio 8V.
You give good advice Pete. All the things to watch out for….

As a follow on to Pete: is there anything we can do short of pulling the TB’s, like opening the air box and spraying a cleaner in there as a preventive if our bikes are working properly now? Not as a fix.

As always, sage advice from the sage of Bungendore, who is always worth heeding in my experience.

That said, a new wrinkle on this, at least for me. I recently bought a new-generation, 2023 Royal Enfield Classic 350, a laughably heavy and underpowered motorcycle that is also entertaining in other ways. Reading through the owner's manual I encountered this on page 94:

"Throttle body should be removed from the vehicle and cleaned with a dry microfibre cloth, usage of throttle body cleaners or any similar solvent or alcohol based liquids for cleaning is strictly prohibited. Throttle body cleaning every 10,000 km/12 months or earlier as required."

Pretty emphatic, eh? I wonder if Pete or anyone else would disagree with this. Or is it a best-practice standard that could avoid resorting to solvents further on up the road?

With all respect, cordially,

Moto

@JohnA

In the short term if, for example, you find some oil misting in the airbox, then I think it's valid to spray some throttle body cleaner (NOT carb cleaner) in via the airbox. You should still remove them even 20K km/12K miles and do a proper clean.


@moto

I would disagree. Does the RE TB have any built in sensors? Or is it just mechanical gizmo?

beetle wrote:

@moto

I would disagree. Does the RE TB have any built in sensors? Or is it just mechanical gizmo?

I'm puzzled. You would disagree with Royal Enfield's service requirement for its own motorcycles?! Is your disagreement with Royal Enfield on its service requirement conditional on the correct answer to your question? If so, how?

Moto

My disagreement pertains to the use of electronics safe cleaners for mechanical aspects of the throttle bodies, and I would completely ignore RE's prohibition should I ever be in the position to clean an RE throttle body.

I would say their prohibition exists for the shaved apes and Harry-home-tune types who would spray solvent based carb cleaner and the like on anything that had the slightest hint of a petrol or oil stain.

Well, that's one theory. No evidence to support it, though.
Here's another way to approach this. Would there be anything wrong with cleaning the throttle bodies every 10,000 km with a microfiber cloth? Would it be ineffective? Damaging?

[quote="Pete Roper"]check all your drain and breather hoses regularly for both attachment, fractures and ensure they are plugged,

+1 on this advice, I have just checked my drain hoses and end plugs, but, they weren't there! Found pieces of tubing lodged above the g/box and swing arm frame. By the look of the pieces I've found, they have all shattered during my last bumpy bitumen journey out west, they were all there when I set off.

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Approved by the Vatican apparently?

moto wrote:

Would there be anything wrong with cleaning the throttle bodies every 10,000 km with a microfiber cloth? Would it be ineffective? Damaging?

On my bike the real improvement from cleaning the throttle bodies came when i got the gummy old oil mess out the tubes to and from the air screws.

All at once setting the tickover synch worked properly and the transition on and off tickover was smoother.

I got the mess out of the tubes with carb cleaner and long wooden cocktail sticks with cotton wrapped around.

All the microfibre cloths i have seen would be too bulky to get in there.

Pete Roper wrote:

Y

. Barely detectable movement in the LH butterfly spindle, I've yet to be able to find anyone who refurbishes them.

On a slightly related note:
Years back, the shafts and bushings on our twin choke Solex PHH-44`s were "wollered" , sucked air and idle speed was utterly random.

The poor mans fix was cut grooves in the shafts and fit O-rings

Worked skippy

Only because carburettors are horrible, inaccurate pieces of shit even when brand new so they have plenty of 'Wriggle Room' for kludges.

Even if you fix the bushings on throttlebodies you still have the issue of the scalloped out chokes and worn butterflies.....

Pete Roper wrote:

Only because carburettors are horrible, inaccurate pieces of shit even when brand new so they have plenty of 'Wriggle Room' for kludges..

Undoubtedly true today , but they did suffice for a century or so..

Still running one on my Hardly Ableson , suits this Neo- Luddite just fine !

I spent most of my adult life wallowing in carcinogens thanks to those poxy things. And they make you smell!

Fuck carburettors! And fuck them twice on every day that ends with a 'Y'!

Pete Roper wrote:

I spent most of my adult life wallowing in carcinogens thanks to those poxy things.!!

Well, I`m sure your Mum always told you not to quit Medical school.

Guys, what damage will carb cleaner do if sprayed through the air box to the throttle bodies, I thought that it will just evaporate quicker than throttle body cleaner and maybe not as effective at cleaning gunk, but I didn’t think it would damage anything?

Always learning

It's not a problem for the mechanical bits of the TB's, but you do NOT want risking any of it getting into the stepper or TPS. It will fuckthemup. Use sensor safe TB cleaner.

That.

Pete Roper wrote:

I spent most of my adult life wallowing in carcinogens thanks to those poxy things. And they make you smell!

Fuck carburettors! And fuck them twice on every day that ends with a 'Y'!

This.

Smelly, drippy, varnishy, weather-sensitive Rube Goldberg mechanisms with all their horseshit springs, rods, check balls and vacuum hoses that fall out of tune at a sideways glance. The majority of my fuel injected vehicles have carried on year after year, requiring nothing from me beyond air and fuel filter changes. The same could NEVER be said of a carburetor.

When an FI system acts up it can be baffling, only because it's so rare. The early systems from the '80s could be quite janky and that's the only reason I know what a  flaky TPS acts like.

Nearly 40 years on, FI technology is mature and about as bulletproof as it gets with electromechanical things in hostile environments.

But when they fail, it's dead Jim. There's no pulling this hose or plugging that tube to get you home.

Although I did see where a guy used a USB charger to power up a dead 5V sensor reference line coming from the ECU!

beetle wrote:

Use sensor safe TB cleaner.

Ok, I’ll bite.  
Is there any specific product you guys use and recommend for cleaning throttle bodies.
Doing a quick search doesn’t reveal any product clearly mentioning being “sensor safe”...
Thanks!

If you Google "MAF safe throttle body cleaner" you'll get plenty of hits.

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So, not so easy after all:
"Throttle Body Cleaner, cleaner for carburettors..."

Of course not a word about it beeing MAF safe.
Would you use this for cleaning your TB's?
I really don't know...!

I wouldn’t.