laverda 1200ts mirage, problem on high revs

mkavci9

mkavci9

Full member
Location
Slovenija
Hello, I have a problem with my laverda on high revs. Let me describe.

the bike starts well, with choke, and also iddle well. Two years ago I renewed and balanced dellorto carburators.  I can go to a ride, and everything works fine, unless I push a bike to high revs. Lets say 6000-7000/min.  Than happen something, like one cilinder stoped working.. bike lose the power, and the sound is different. Than if you drive lets say 5-10 km more , everything start to work normaly again. Even  next day when you start bike, and go on the ride, everything works smothly and normaly. I thought that maybe there is no air in a tank, so lack of petrol on high revs, but even if you open the tank the problems are still there.
I have electronics Sachse electical ignition mounted.. I run on 100 octane petrol.
Have to say, that this problems started,  when I put in petrol lead aditive, for valves.  Is this maybe the reason?  I didn't check spark plugs for now. Have someone any idea what can be wrong ?

thanks a lot

here si the link to the video, when this problem first started. I usually don't rev the bike like this, but this was for a video :) Bike was hot already. I hope that I didnt made some damage to the engine.
https://youtu.be/qU4clGCT_Gs
 
Have you checked the flow of fuel through the taps?
I haven't watched the video clip to compare, but my Jota had a misfire at wider throttle openings and it was due to the fuel taps having insufficient flow. New correct taps cured the problem  :)
 
Hm, i have original fuel taps, and I didnt check them. But why would this problem persist for 10 kilometers and than gone. I would say that if this is the cause, than this strange running would last for few moments, and than after slowing down would be son better. But is not.
 
Fit new plugs and caps and cut a few mm off the HT leads before screwing on the new caps.

I'm not a fan of Marving 3 into 1 exhausts on Laverdas.
In themselves they can strangle higher revs, but I don't think this is necessarily your problem here.
 
thanks for opinions.  what exactly you mean with this sentence?  "In themselves they can strangle higher revs"    My bike has marving exhaust on from when she cames in outr house, in 90's. And before ths problems didn't exist. 
I will try to change the caps on the plugs and check the plugs color. 

Do you use lead aditive?  Do our bikes need it  ?
thanks
 
Hi Martin,
I would check all the connections into the  ' Sachse' unit.
Just wondering whether at high revs the vibrations from the engine are causing a wire connection at the unit to break down?

Andy
 
I had a very similar problem on my 3CL. It was the plug caps. Once the motor was hot and at certain RPM's it would run like shit. I replaced the BOSCH caps with NGK (resistor type) caps and never had a problem since.
 
mkavci9 said:
what exactly you mean with this sentence?  "In themselves they can strangle higher revs" 
Do you use lead aditive?  Do our bikes need it  ?
thanks
Click to expand...

In my experience 3 into 1 exhausts do not allow the gases to flow well, unless properly designed, which the Marving is not.

I think the octane rating of the fuel is more important than lead additives. Higher compression, higher octane.
Plus 98 octane is less volatile than 95 so is more stable over winter, for example.
 
Paul Marx said:
A Marving, 2/1 or 3/1 transforms even the mildest engine into a noisy pile of crap.

Paul
Click to expand...

hqdefault.jpg
 
mkavci9 said:
The bike starts well, with choke, and also iddle well.
I have electronics Sachse electical ignition mounted.. I run on 100 octane petrol.
Click to expand...
If it's a standard Mirage running 8:1 compression then regular 91 octane will be fine: when I switched to this my Mirage stopped fouling its plugs... suspect the high octane and a plug lead/cap issue could be your problem..
 
Beware of comparing octane ratings between countries.
MON or RON system?
IN the UK the numbers are 95 or 98.
I'm thinking your 91 is an equivalent to our 95.
 
Grant said:
I'm thinking your 91 is an equivalent to our 95.
Click to expand...
Copy that: however, here we have 91 (regular), 95 (premium) and 98 (Super Premium <or some such depending on the brand>). Then there's all the in betweens with Ethanol content but best not go there... :o
 
All ours has 5% ethanol, soon to be 10%.
This will screw up a lot of older vehicles.
 
Hi Martin
              Reading your post I think you need to take a logical approach to fixing the problem. The first thing I would do is drain and rinse the fuel tank as you suspect the fuel additive could be the culprit. Whilst  the tank is empty, remove and clean the taps. This will rule out fuel starvation and contaminated petrol. Try the bike at this stage but take a set of new plugs and a spanner with you. If successful you'll know not to use additive again, if not change the plugs. If that doesn't cure it you'll need to remove and strip the carbs paying particular attention to the fuel flow and float heights. If the problem persists, it has to be the ignition. Replace the plug caps and HT leads and work your way back from the coil connections to the pick-up wiring looking for any loose or suspect cable routing. Keep us informed, as with any mechanical object "if it can go wrong, it will, given enough time". Good luck.
Kind Regards  Bob   
 
I do not think this is fuel flow problems, and is it an Anniversary not a TS (makes no difference engine wise really)

in the video the bike idles nicely and then stumbles at 6/7000 rpm, this would not happen if a fuel problem unless 6/7000 rpm was held for a good long while, as in the video you could do that with the fuel taps off, maybe twice.

electrical I reckon, so strip the carbs to the bare body and check them all out for dirt/crud to start with.

CLEM
 
hello, thanks for all answers.

CLEMTOG, is and 1200 ts Mirage bike, just looks like aniversary, because we get the bike awful repainted, and than someyears ago i repainted and customized it like it looks now.

So, what  I did,
- checked and cleaned  the fuel taps. Flow is ok. Tank was reimpregnated with some special stuff few years ago during restoration, and is clean.
- checked round filters ond carburators and everything is clean. Carburators were rebuild, ultrasonic cleaned and calibreted with carbtune. I cleaned and washed air filter to.
- cleaned the candles. they were a bit carboned, but noting special. I already have new  NGK 5 ohms plug caps
- checked and measured the alternator filling and Regulator/resistor working, help with instructions on forum. Woks ok.
- changed also brand new gel agm battery, because old was making the problems.
- checked and cleanned, grindend the fuse box and found that on 8A fuse the contact and screw was a bit lose, prom that contact the 12V input goes to Elektornik-Sachse ZDG3 ignition goes.  i fiksed it some way, but have to remove whole fuse box and made it more stable.

now, the problem is, that when I reasebbled all together, the bike started, but ran ony on outer cylinders. The middle one exhast was not hot. I unscrew the sparks plugs, and saw that there is no spark in middle cylinder. So i preauseme that this was the problem when bike lost power on hgh revs, because it behave like running on just 2 cylinders.

I had exactly same pribme few years ago. Almost forgot, and found email in history.  I'll copy the mail to sachye company here, and you will understand about what I'm talking
Last time they fixed my ignition box which I sent to them.  But, i preausme that is some fault on my bike that is ruining outputs on ZDG3 ignition. What you think?
I have to tell that single ignition coil is still original , that double cylinder coil is new, Dark green, think that dyna brand.
U think that old coil makes the problems?  bad battery voltage, or something else? This time i didnt made any short circuit by mistake.

Mail to sachse;
HEllo!

I have problems. Seems that Electronik-sachse Ignition is faulty.  Talking about Laverda 1200TS Mirage, year 82. I bought the ignition by your company 8 year ago.

All hapened realy strange. Last week  I had a ride, and when I came home, stopped the engine and trying to run it again, it didn't start. Refiled batter, and it started.
I checked the voltege, and alternater filled about 13,5 v at 2000rpm.  Maybe I had to long ride with long lights, dont know. I also tried to change a spare regulator, but same voltage.
OK, This is not the major problem now.

When in disatached battery, connect cables, whatever, looks that i made some electric short contact, and burn the ignition. This is only possible option from my point of view.
I put spare park plugson cables, to see the spark, and turned the engine. Ignition is working(giving output signal) only for single Coil (output 1 on ignition), but not for Double Coil (output 10)

If I try to change output, between connector 1 and 10, means , to change signal to Coils, again, only output 1 is working.  Both coil are working, giving spark, if they get signal.
I tried  to change even inputs (small cables ) comming  form optical sensors on crank, and seems that both works. I tried all combinatins.  Output 10 on blaxk ignition box, never give signal.

Maybe is important, i noticed also that Dual coil (green, Dyna brand) was kinda hot. lets say 50 degrees. Is this normal? Because single coil isnt hot.

What is naw to do? any suggestions? Is this Ignition fixable?  Would you be able to repair it? u have same box  on stock?
Tanks for any advices.

end of mail to sachse
 
Replace the spark plugs.
Replace the spark plugs.
Replace the spark plugs.
:)
Cleaning is often not good enough. Happens to lots of us here on the forum. It bothered me at first, but now I just replace the plugs and it fixes it. Idling too long is my main cause.
 
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