Just got a new to me 2000/1 ST2, It has nearly 14k on it, standard 15:42 gearing and starts, idles and runs well, sounds mechanically great. It will however only pull just over 120mph. I am wondering where to start to release it's full potential. Thanks.
Hi Dan, the Sport Touring section is one where, sadly, Tumbleweed blows around unhindered . ie it’s unfrequented. However, this isn’t a question that’s confined to the STs so perhaps @El Toro could move it into the Technical section where many more will see the question. I do believe, from earlier FB posts, you now suspect the valve clearances to be the cause but I’m sure others csn shed light on that.
Cheers Paul, appreciate the comment. I am not sure that the clearances are the issue but they are an issue. It would be nice to do them and regain full performance but I doubt it will be the case. Fuel filter is also old so I will do that and inspect the Pump and regulator, they usually give starvation symptoms which my bike doesnt show. If no one had said it should be 20 mph faster you would think all is well.
Not sure how this applies to ST2 but I dropped the gearing on my ST4s and as a result it pulled to the redline in top at 161mph, so maybe gearing change could help.
It should pull 135 ish on standard gearing which I have. I am thinking there is some power missing. Maybe something to consider when I find the full power.
If it starts and runs well, then hopefully just a case of working through the usual suspects. There’s a good chance it’s a combination of lots of small things but of course this can be a right can of worms. You’re right to settle on the pump and filter and particularly the internal hoses, as an old filter can certainly drop top speed as it’s only symptom, but agree not usually by that much. Ditto the internal hoses, they often break down badly enough to be detected easily, but sometimes can just weep slightly or even kink and “flatten “on a bend. Other than that, you could work your way through the engine with compression checks onwards, which I’m sure you intend to do.
You may be down on power. I never rode an ST2, but a few questions to consider first - Where are you doing 120 mph? Is it really flat, without headwind and long enough for the bike to fully top out? How are you measuring the speed? Are you about the same size and weight as the tester who got 135 mph? Are you getting fully prone in leathers with the mirrors folded up? (The road tester will have) are you using good fuel, is the bike well serviced, are the brakes free, tyres at right pressure… etc…
When you were at 120 @Lucky Dan what were the engine revs? Csn you recall? presumably you were in 6th at that stage too?
I mentioned that I regeared my ST4s as it would not get near red line in stock gearing 6th gear but 2 teeth up on the rear had it redlining no problem in 6th at a much higher speed than was possible with stock gearing. 6th on Ducati is nearly like an overdrive gear. Aside from that maybe also check the TPS settings and clean the connection, my SS suffered due to rusty TPS connections. Also is the fuel consumption normal? What are you averaging?
I do my best on all counts, I can usually squeeze good top speeds out of machines of 130 hp. There is definitely some more to come if I can chase it down.
My ST2 had a dodgy speedo. Mine would read 80, my mates multi 95. Worth a check. Think mine would do indicated 130 or so iirc, on the autobahn on Germany trips obvs and I rode it flat out everywhere. Enjoy!
Actually @Lucky Dan , @bradders has a point, it may be worth buying a GPS speedo off eBay and seeing how that compares with what the speedo is saying. Alternatively, download an App called MyRide by Yamaha, start it and go out for a ride. It will record your top speed (amongst other attributes) which you can compare with what you saw on the speedo. Both are simple tests to establish the accuracy, or not, of the current speedo.
New development with the tacho. It reads a lot lower with lights on, and with full beam on it's getting quite close to indicating actual engine revs ! In top gear on the test track it gets to 122 on the speedo and 9000 revs on the tacho. I have had a look on the gear commander app and it would be doing about 150 with those revs, bit optimistic that. The speedo is looking a bit lazy after all, could be getting close to spec speeds but feels slower. I forgot to take my phone out so no GPS yet. Engine temps have got up to healthy 160-170 with a decent ride instead of the 154 I was getting on my first couple of steady tests. Parts have arrived for fuel pump and she is off for a valve job tomorrow, he is keen to get them spot on, not ball park with no prompting. Very encouraging. Jonny G at Thurnscoe.
I’m guessing your ST2 has the single phase stator (just 2 yellow wires coming out), if so what you describe is not uncommon due to a lack of watts available to power everything.
