Brad The Bike Boy: April 2023

Saturday, April 29, 2023

Multistrada 1000 idling issue - Another (more complete) take on it.

Some time ago I had a MTS1000 in that had been set up badly to overcome a non idling issue. That was part of a minor service and not much disassembly, and I got around that electronically. See here -> MTS 1000 not idling That particular bike had a very vague history and a couple of dash replacements with no record of actual km.

A bit of MTS1000 info from that report - The MTS1000 was the first Ducati with an idle control valve ("stepper motor", etc). Any model with an idle control valve doesn't need the air bleeds (the little screws on the sides of the throttle bodies that allow air to bypass the throttle blades) opened, as their primary function is to allow you to set the idle speed. I also use the air bleeds to equalise the idle mixture between the cylinders, in which case you open the air bleed of the richer cylinder to lean it off to be the same as the leaner cylinder. Meaning one air bleed should be fully closed.

Seeing air bleeds wound out on bikes with idle control valves really winds me up. Just not how it's meant to be done.

Recently I had another MTS1000 in for an 80,000km service that I found in the same sort of tune set up - air bleeds wound out one and a half and two and an eighth turns and idle trimmer @ +20. My response was to wind the air bleeds fully in and set the trimmer to 0 to see what happened, but there was no way it was going to idle successfully.

As I was doing a major service, and had just popped the fuel tank back on to run it, there wasn't a lot of time to be spent pulling it again. That made it worthwhile to pop off the tank and airbox and have a looksee at the throttle bodies. As below.

Icky. But not unexpected for 80,000km, especially on a model where you don't pull the airbox for routine maintenance like you do a Desmoquattro for instance. None of the 2V models really give you easy access to the throttle bodies to clean them at service. So I broke out the Threebond Engine Conditioner - which despite the name is a throttle body/intake cleaning spray - and gave it all a good clean up. I sprayed some down the idle control valve air hose as well, as they can also get claggy.

It's quite awesome for getting fuel residue and combustion gunk off. I soak carb bits in it, but don't give them too long is my advice.

And Voila! Lovely.

Back together again, it ended up with both air bleeds still full in and the idle trimmer @ +4, idling happily as desired.

The 851

The 400SS

I bought this 400SS (genuine 93 model Australian delivery! Woo hoo huh.) after seeing it in Ebay for what was possibly an good price. As ever, good was too good to be true. Badly repaired and rusted out fuel tank, badly repainted side panels, lots of km (83,000 of the bastards), etc. You know, the usual. Purchased in October 2012, as of now (Jan 2014) I've nearly finished a major service. The cam timing is done with some of the Madasl adjustable pullies that have been drilled in 4 different settings for easy dyno testing. And I have some 900 headers to try a 40mm dual exhaust set up on it (ala M400). Not a great deal of progress for 15 months, so it's taking on a long term feel. There's an F1 endurance style seat base (more taper at the rear) and front fairing sitting around, which will require frame mods to fit. It's a bit of a mental sticking point as this time. But hey, it's not like I can devalue it much more.

The Mighty KR1S 250

How it looked the rainy night someone came to take it away. Painted all black when I bought it, at some point later I realised i could rub the black off and have much of the original colour scheme underneath. Although the main fairing was originally from a red KR1 I think, and definitely badly repaired more than once, so it stayed black. And the tail panel shown was bought to replace the one I smashed the only time I crashed it and the last time I rode it at a Sandown track day. A sensational little bike, holed pistons and frequently failing stator windings aside. The first bike I rode on a race track and the first bike I had my knee down on. And a great commuter too I found. It's sometimes nice to have a bike that won't wheelie past the city speed limit in first gear.