TZR fuel problem?

[bikerg]

Hi,

My TZR 125 is still giving me hassle.

It does around 55 miles on £5 ~ 6 litres, and maths says thats 40 mpg ish.
Is this at all normal?

I have put on a new fuel filter (it is on the right way round), and new fuel line as I was worried about it leaking from connections, still no change.

6th gear gives me hassle too, I don't seem to get any power at all, the bike just slows down when i change up, even at 8-9k rpms. I also get spluttering at 9.5k rpms in every gear, I have cleaned the carb several times before.

Any ideas?

Thanks!

[imadoofus]

your jets are the correct specifications?

sparks igniting fuel properly?

[bikerg]

I don't know about jets to be honest, my workshop manual just tells me settings shouldn't need to be changed.

Spark is fine, nice and bright blue. Recently had trouble with a dud spark, but put a high performance NGK in and it seems ok.

Also, if I ride for 5-10 mins at 8-9k rpms then drop then throttle approaching a village etc. When I hit the throttle again, it acts as if there is no petrol, then it slowly picks up (while spluttering) then its fine...

Seriously confused

[Bomberman]

Has it got the full powervalve dealy fitted? Or are you just running derestricted with it open? What spark have you put in it now?
Anyway, 55 miles for £5 is poor. Mine gets 100 miles for ~£7.
____________________
'Allo! My name is Inigo Montoya, you killed my father, prepare to die!
'89 TZR 125 - '94 GPZ500s - ZK3 GSXR600 Alstare

[bikerg]

I've got the full servo gear, with that casing on the side of the cylinder with a pulley thing to turn the valve.

I put an NGK BR8ES (i think) in it, but it's NGKs Iridium model, the electrode is needle thin...

[Bomberman]

Hmm, bit of a longshot, but put a BR9ES in instead. That's te recommended spark (and the one I've always used), but the handbook does say that a BR8ES should be OK. But something to try for about £3 eh? Also, is the powervavle working OK? Not getting stuck or its cables sticking?
____________________
'Allo! My name is Inigo Montoya, you killed my father, prepare to die!
'89 TZR 125 - '94 GPZ500s - ZK3 GSXR600 Alstare

[bikerg]

Powervalve seems ok, although it looks like its leaking...

[Gazdaman]

Shouldn't be any oil under that cover.

Does it go through its cycle ok when you turn the ignition on?

Gaz

[Kickstart]

Hi

There is no "oil" under the cover, but there is a fair amount of cack that goes down the exhaust and that can be pushed out around the edge of the cover if it is not sealed up correctly.

An 8 spark plug does sound a bit low. I would expect a 9.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[simon1221]

I get about 80 miles on 8 litres (£7), but i havent got round to replacing the float needle jet , so have to turn off fuel tap overnight.

Give the Pv a clean, as it solved all my running problems (partly because it was in backwards before).

If the carb is fine then i have no more ideas, if the plug is clean (not black) then it is even more confusing!
____________________
DNA50 (sorry) ->> TZR125l >> GPZ500S

[bikerg]

The powervalve goes through its full cycle, I can hear it turn twice. If I start the bike, then switch off then on, it turns three times.

I'm not sure what the "oil" is, there is a thin black liquid which is sprayed on the inside of my fairing and down the left side of the engine, it seems to come from 2 holes in the powervavle thingy on the left of the engine (with the cables coming out of it).

I used to use a BR9ES, but the bike died with it, changed to my current spark and it started fine, I've lost my trust in the 9.

Is it worth switching the fuel tap off at night? Where does fuel leak from?

[Kickstart]

Hi

An 8 plug will run hotter than a 9. The 9 is more likely to foul up round town, etc, while the 8 is more likely to run too hot, blister and fail (possibly damaging the piston at the same time). However on a 2 stroke the spark plug is a consumable, and unlikely to really be worth trusting for more than 1000~2000 miles.

The "oil" coming out from around the power valve is probably the same stuff that you get dribbling out of the end of the silencer. Basically a mix of burnt and unburnt petrol and 2 stroke oil.

The reason you should turn the petrol off is that if the needle valve in the carb is not sealing correctly then it will allow fuel past. With the petrol turned on it has a nice large reservior of fuel to allow past. This fuel might come out of the car overflow and onto the floor, or it might overflow into the engine. I left my 1200 Bandit on prime one night (bypasses the vacuum operated tap that is fitted) without noticing, and by the following morning it had emptied over 10L of petrol through the carbs and into the engine and airbox.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[bikerg]

Ok, did some work on my TZR today.

Took out the spark plug, the BR8ES. It has oil around the edge (by the screw), and some strange carbon/oil looking chunks on it too. The electrodes are a tan/brown colour, with the top electrode covered in oil at the base. The ceramic is brown, it looks like parts are flaking off slowly...

I'm still not sure about the oil, I have attached a photo, showing where the oil is, there is no oil on the other side of the bike! There are "drain?" holes in the bottom of the powervalve control housing thingy, and when I take the cover off, it is covered on the inside in the black oil...