The Tmax MK3 fuel pump is a known issue that Yamaha chose in most countries to replace under warranty when they went bad, it not a case of if but when. You are right it can be fuel lines, injectors, etc and those should be traced.

I don't know what issue maxsymiser is having but obviously believes he should change the pump as that was the question.

The pump failures or TMF (TMax fever) starts to happen when the pump fails to initiate and build pressure in the system, a replacement pump fixes this issue. I have had three MK3's and change the pumps in two of them, I didn't thave one of them long enough for it to develop an issue.

Testing sometimes requires buying a new equipment or paying a mechanic to test it... if you can test it by changing out a part for £30 and 4 hours work instead of paying out a ton of money, what is the better option?

Incidentally on my current MK3 I did change both the FPR and the pump, at a cost of £75 vs the £300 cost of the entire unit. Getting the FPR out was ridiculously hard and, after handing over to a mechanic friend recently, was found to be in perfect working condition.

So if you have a TMax and the top of the pump has a blue and green dot, its from the dodgy batch Yamaha bought, if it has a brown/orange dot as well it from the good batches after. If you are looking to buy a MK3 or late MK2 have look at the top of the pump so you know what you are getting and if you still want to buy replace the pump as soon as you can... and if you want a little more oomph with out taking a mpg hit get a 3 bar one (OEM is 2.5 bar).

Funkycowie wrote:... and if you want a little more oomph with out taking a mpg hit get a 3 bar one (OEM is 2.5 bar).

But that will STILL run through the fuel pressure regulator, which will reduce it to 2.5 bar. Also change the regulator to a Polini to get a full 3.5 bar...

http://www.polini.com/catalogo/en/risul ... rom=camamo

Still gives it more oompf even though its hitting the 2.5 bar standard, not sure why but its noticeable. As for changing it to a Polini one, thats what I used but there was no noticeable difference and it was a real major pain to seperate that part of the pump unit, it was not worth the effort and I probably came close to breaking it due to the plastic not having much flex or access.