Triumph TT600 white smoke

Published on 12 January 2023 at 18:39
Triumph tt600 project motorcycle

Here's another bike that is pretty border line as to whether I was going to fix it or take it to bits. It's fuel injected and I normally only dick with carbed bikes. I understand how efi works but I just prefer carbs, it doesn't feel right using software to make a bike go faster. It's witchcraft. Anyway this was an odd one, the seller told me it was blowing white smoke - he wasn't wrong. First time I fired it up I thought a new pope had been appointed - I couldn't see the end of the workshop. When an engine smokes the first thing to do is see what colour it is - blue is bad, that means oil is being burnt and is usually very expensive to fix and would not be worth doing on a bike of this value. black usually mans it's running rich - on a fuel injected bike that's usually leaky injectors, fuel pressure regulator failure or temperature sensor problems. this was pure white, which is either unburnt fuel, moisture in the fuel or head gasket failure, which allows coolant in to the combustion chambers. Compression was spot on so I assumed it was fuelling.

these bikes have pipes going from the throttle bodies to the Idle Speed Control Valve, if there are any air leaks things go wrong very quickly. Triumph use these horrible rubber connectors to join the flexible pipes to the idle valve, they split and allow air in, which messes up the mixture - it's allowing unmetered air in, which is a bad thing. There is another pipe that uses similar dodgy technology that goes from the airbox to the ecu. The ECU is a Sagem unit that has a built in pressure sensor - if that pipe is disconnected or leaking it will ruin your day. I would suggest if you have any problems with your TT600 these pipes are the first place to look.

mine is running nicely now although it does have a very common Triumph TT600 issue - really bad ECU mapping. Older bikes suffer from poor cold starting, for some reason the map sets a silly lean mixture at below 10 degrees. The standard map also gives a flat spot at 2000 rpm and another one at about 4k, which makes riding the bike in town a mare. When they hit the cam and come in song they are fantastic. It's all in the mapping, which some say is to do with emissions. There are some maps available on line for free that really sort these issues and make the bikes a whole lot better, it's easy to upload them to the bike by using a diag package called TuneECU  and a suitable OBDC diag cable. You have to pay a licence but the software and maps are free, the bluetooth dongle that connects to the bike's port is about a tenner.

The bike still needs a lot of work from where somebody dropped it but I don't want to do too much until I have it running better. I have a new footpeg hanger on order and also need a new rear sub frame as the aluminium tabs that the rear footpeg hanger mount to have snapped off. The fairings will all need repair and paint, the tank needs a rub down and probably a repaint too. Everything tells me that this is not commercially viable but I just can't stop myself. That's probably why I never seem to make any money. 


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David Derbyshire
2 years ago

It might be worth joining the tt600 forum facebook group. There is a wealth of knowledge on there, sort the issues snd these are simple. Then you have a wolf in sheeps clothing