Legend Tt 900 Losing Power.

Lazarus · Apr 25, 2019

Dear Forum Members,

I would like to ask your help.
Recently I bought a 2000 Legend TT 900 for a project.

Back ground: It was my old friend bike he passed away 2 years ago in cancer (rest in peace). Recently I bought a bike from the wife. And I would like to put back in the road. I managed to clean the tank carburettors etc. It's up and running. But always a but....

The Tachometer basic position is in 9000RPM It's working but everything is shifted. 45 depress to left.
Thats is the smaller problem.

The really issue is the bike is limit on 70mph. It's just stopes not gose higher.
The RPM needle is jumping beetwen 4000-5000 nad no mor power. In lower geras and lower speed no poblem.
In neutral is fine.

Can by some ECU limit down on 70mph?

Thanks L.

Callumity · Apr 25, 2019

If I understand you correctly the tachometer scale has shifted relative to the needle? Or has the needle itself moved? A photo would help but google tachometer repair uk and you will find specialist repairers.

Your explanation of the engine problem leaves it unclear how long the bike was standing and whether you have cleaned air filters and air box and whether the problem is fuel or electrical. Does it misfire when the needle jumps? Are the carburettor jets definitely all clear? Is the exhaust corroded or blocked? Dirt in the fuel tank clogging filters?

English is obviously not your first language but we need a bit more detail to diagnose the problem.

Lazarus · Apr 25, 2019

Callumity said: ↑

If I understand you correctly the tachometer scale has shifted relative to the needle? Or has the needle itself moved? A photo would help but google tachometer repair uk and you will find specialist repairers.

Your explanation of the engine problem leaves it unclear how long the bike was standing and whether you have cleaned air filters and air box and whether the problem is fuel or electrical. Does it misfire when the needle jumps? Are the carburettor jets definitely all clear? Is the exhaust corroded or blocked? Dirt in the fuel tank clogging filters?

English is obviously not your first language but we need a bit more detail to diagnose the problem.
Click to expand...

Thanks Callumity,

Sorry for my English I still working on it. ( If I writeing something unacceptable, please fell free to correct me.)

If I good to know the bike not used in the last 2 years.
- The air-box with and air filter is new OEM parts I had to replace beacuse the screws are stuck in the inserts.
- The carburettor jets are cleaned.
- The fuel tank washed and cleaned.
- I bought a bike with a short aftermarket exhaust, but I put back the original one. I don't see any corrosion on it. I didn't looked for any blockage.
- the clutch is feels good

Hopefully I will have some free time on this weekend and I can check the exhaust and the fuel filter how is looks like now.

We did a test run with one of my biker friend this afternoon. Both of us a 15mile. I try to explain the problem what we experienced:

After the engine is warmed up.
- in neutral we could revving up the engine until 8000rpm.
- in the first 4 gear feels like no power above 5000rpm. Top speed somewhere 50mph. My friend felt some misfire.
- in the 5th gear until 60mph no problem and there just stopes. If I realise the throttle and slowly start to pull it I can reach the 70mph, but above nothing.

Callumity · Apr 26, 2019

Fit the short exhaust and see how it runs. I suspect your problem may be carburation - if the jets were enlarged for the short exhaust it will run too rich with the old one.

stevethegoolie · Apr 26, 2019

Give it a good dose of Redex or another similar fuel (petrol) system cleaner. Even if the carbs look clean they may well not be clean enough. Not uncommon with these bikes when they have been left standing.