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My little Spada and her 'issues'

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by nina, Jul 15, 2012.

  1. My beloved little bike is worrying me and I was wondering whether anybody could help me out with this.

    One and a half months after I got my Spada I believe what I observed was pinging. I changed fuel brand, filled up a whole tank of 98 octane, but it remained. I read somewhere something about spark plugs, so I looked at those: they were fouled up, so I exchanged them. The knocking stopped, so I assumed that my Spada was happy and that made me happy too.

    Another one and a half months later (now) I had exactly the same phenomenon: engine knocking, a tank ful of 98 doesn't change anything, looked at the spark plugs and they are fouled up again!
    The guy at the spare parts of Peter Stevens (actually the spare parts guys are the only people I like at PS) seemed to be quite knowledgeable (not the youngest anymore as well) and gave me the tip to look at the air cleaner. Does that make sense? Has anybody experienced something similar?

    I wanted to save the air-cleaner-task for tomorrow as then I would have the whole afternoon for doing so. But being curious as to how to get the tank off, I had a quick look today. Too quick, as I couldn't see how to take the fuel and vacuum tubes off. So I left it at that, and didn't think of it further. I took off for work and didn't think anymore about it. One km into my ride, as I was stopped, she stalled. Jumped back on right away though, and only after another couple of km, did I rememer that I never turned the fuel tab back on ON, it was still in the OFF position!
    Does that mean that I would have had litres of fuel running out if I had actually disconnected the fuel tube? Will I now have to drain the tank if I want to look at the air cleaner?

    I am thankful for any tips, but on the other hand I'm starting to believe that it is about time that I used my saved money to have a major service done. As far as I know it could be anything that causes the engine knocking. So far I have only been treating the symptoms: exchanging the spark plugs :(
  2. What you describe as engine pinging Nina, is also classified as knocking. Engine knocking is a phenomenon that occurs when the spark plug ignites fuel not only only in the combustion area, but also in other areas. This is inappropriate and creates a resonance often recorded as 'pinging'. For more details refer http://en.wikipedia.org/wiki/Engine_knocking

    Having explosions occurring in different parts of your engine does not infer that your engine is failing. It highlights that the air-fuel mixture in your Spada is far too rich. I've noticed this to be a regular problem in Spadas including mine directly after purchasing.

    A good indicator of air-fuel richness problems is fuel consumption. My previously faulty and rich Spada would average 6 litres per 100 k. Far excessive consumption. They should achieve around 4.10 to 4.4 litres per 100.

    It's possible that newer spark plugs will ignite fuel more appropriately, however as you've noted, this is not an appropriate solution. Furthermore changing fuel blends will not impact the air-fuel mixture in your engine significantly. You're engine will still 'run rich' as is evident in your case. I assume your "fouled spark plugs" are fouled in the sense they have a black coating upon them. Once more this is indicative of a rich engine. Replacement spark plugs will only acquire a similar coating.

    The guy at Peter Stevens was quite right in the air cleaner tip. If your air cleaner/filter is blocked there will not be enough air reaching the engine. However fuel supply will remain constant. Thus there will be more fuel and less air. A rich mixture. The air cleaner is usually the first step in diagnosing rich mixture problems.

    Should the air cleaner be faultless, the next step is to inspect the choke cable. If the cable is stuck the engine will be constantly "choked". Choking, or depriving the engine of air will obviously make the mixture richer. However if the choke seems fine, then a carburetor clean and rebuild is in order. Pay special attention to all air passages ensuring they are not blocked. This isn't too difficult, considering I've done the same job myself.

    The final step in remedying a rich mixture fault would be to service the engine. Valves and ignition out of time, will result in inappropriate combustion, and possibly a rich mixture. Check the timings with specification, and this should most likely solve the problem. This part may be rather challenging, and a mechanic would be a good idea. However this is only if all else fails.

    The vacuum tube should be disconnected from the tank side. Pulling firmly, with some shaking, should see it come free. I found that disconnecting the fuel tube is best done from the carburetor entry. The connections here are rather weak, and don't cut/bruise fingers, upon release.

    Did you turn the fuel tap back to ON from OFF after you jumped off? If that was the case lack of fuel reaching engine was responsible for your stall. If not then it was probably flooded. Once again indicative of a rich mixture.

    If you disconnected the fuel tube, yet had the vacuum tube connected to the tank, then yes the fuel would have run out of the tank. Only when the vacuum tube sucks on the tank, a valve opens, allowing fuel to flow. It's a safety mechanism.

    You will not have to "drain the tank to look at the air cleaner". Just do as you've done, but disconnect the tubes this time.

    On other topic your display picture. Is that directly from the sale ad for your Spada? I ask because I've seen that similar picture/bike advertised everywhere when I was searching for Spadas haha.
  3. Thank you so much for your helpful reply Demond!

    Yes, this is what the spare parts guy mentioned as well. Now that I am given numbers to compare it with, I am even more so the opinion that my Spada doesn't consume too much fuel: I need about 3.8 - 4.0 litres per 100 km, depending on what kind of riding I do.

    Exactly, my spark plugs have a black coating after not too many km's of useage.

    I turned the fuel tap back on ON after I had done a couple more km's after the stall happened. During that bit of riding I was thinking about what could have caused the stall. It took a while until it occurred to me, that I never turned the fuel back on.
    I had never disconnected either fuel, nor vacuum tube. I simply turned the fuel off, took the tank screw off, moved the tank a bit to the side, and peeked underneath. Didn't even have a torch at hand, so I didn't see the end of the tubes properly - then I gave up, as I didn't want to spend much time on that. So I put the tank back in place and screwed the tank screw back in. I never touched any of the tubes.
    That's why I'm now afraid that my fuel tab isn't working properly. Well that at least the OFF position will not be actually cutting the fuel supply. Otherwise how could I have gone 3 km without fuel?

    Yes it is. Never updated it, I should though :)

    Thanks again for your post, was a very good read!
  4. pinging it not cause but rich air/fuel mixs but that it don't help pinging is cause by the spark plug firing to early witch can be a timeing problem or if your runing a low octane fuel becasue it is easyer to ignite it can combuse to early a spark plug should fire just before TDC but if there fire 2 early it causes pinging
  5. have you been using 98 the whole time you've had the bike? sounds like a waste of money to me for such an old bike with low compression tbh..unless the engine has been modified somewhat.
    back in the 80's they didn't have fuel like that
    and a higher RON or octane numbers does NOT equate to better fuel quality..common misconception.. if I was you I'd do yourself and your bike a favour and make a start by, Googleing what Ron fuel values mean and then using a fuel better suited to your bike like 91 before you cause more problems
    • Like Like x 1
  6. Pinging is NOT knocking!

    Just get the thing serviced, and the carbies tuned and balanced.
    And stop running 98 in it - anything higher than 91 will also give the leaning out symptoms you describe, since the jets on the Spada are so small...
    • Like Like x 1
  7. Pinging is NOT about the fuel combustion beginning in the wrong area of the engine, but the wrong moment in the cycle - high compression engines will ping too soon with a low RON fuel. Copying and pasting from the web without proper context is dangerous.

    The only benefit of 98 over the 91 that the spada needs, is that it might clean up some fuel system gum & other deposits. You are not going to get any anti ping / knock benefits.

    If your plugs are fouled that's entirely a fuel air mixture issue. Hot fouled plugs could cause preignition which has similarities to pinging.

    How long do you warm up the bike on choke? Do you ride with the choke on?

    Check that your filter is clean (get a new one if you don't know how old it is) and that the choke works - but given your fuel consumption is ok, prolly not a choke thing. Beyond that it's off to a knowledgable person to diagnose.

    Nina, you might get some extra info from a website called Dansmc. Google it.

    - - -
    Tapatalking loud, saying somethin'
  8. NK fouled plugs are a rich fueling issue. Brown plugs might be a lean fuel issue.

    98RON is more dense so it can richen up fuel mixtures. Also no real benefit so agree that it's a waste of money on a spada.

    Definite +1 on a service.

    - - -
    Tapatalking loud, saying somethin'
    • Like Like x 1
  9. The fuel that's already in your carby float bowl before you turned the tap off will still allow the bike to go a short distance, even though the tap wasn't turned back on before you rode off. I hope you're able to get it sorted Nina and back out enjoying your bike. :)
  10. "Knocking (also called knock, detonation, spark knock, pinging or pinking)"-wikipedia

    Wikipedia is not always right. My apologies. A possible definition error regardless, but it still reflects the cause outlined in the OP's symptoms. Rich air/fuel mixture.

    Your fuel consumption is much better than mine. Although I may be heavier. Yet the plugs are indicating your fuel mixture is rich, or not being ignited appropriately, hence pining. Once again my bad haha, it was 4am. Anyway yeah possible causes include ignition timings, maybe valve clearances not providing enough compression, or a carbie problem.

    All issues you're best giving to a serviceman. I got all my rich problems fixed by Sis at S Jay motorcycles. He's quite cheap was about $300 for a fuel service including valve timings, paying close attention to the fueling problems. It's been almost 6 months and not a beat was missed.

  11. I'm with Rob here...what your describing is classic rich. The resulting deposits on the fouled plug glow hot and cause your pre ignition which is why the problem goes away temporarily when you fit new plugs.


    Full Service or at the very least...

    1] service or replace air cleaner
    2] tune & carb balance
  12. Yeah mate, of course you're right.
    Was just referring to what the OP thought was pinging...

    A carb service is definitely in order, and I'd be interested to hear if they were unbalanced since I've never that "never" happens on a Spada...
    • Like Like x 1
  13. Pre-Ignish isn't healthy for a bike motor. A good way to pop a rod on a bike. Most common cause of death to a turbo motor besides lean out.
    98's no good, no one remembers to clean the air filter or do it right and change down a gear or two
  14. long story short: do not use 98 in your bike; get it serviced
  15. i was making the assumption that a spada is just another honda 250 based on a vt engine ( v twin - 2 cylinder )...

    But if its only a single then your right, single cyl - single carb - no balancing 2 carbs..

    Clean / replace air cleaner & set the mixtures

    its a honda....my interest has already peaked....
  16. You had it exactly right first-time Mike - it's a 90deg V-twin.
    All I'm saying is that a trusted mechanic once told me the carbs never go out of sync - I still say sync them, but I'd be interested to hear if they needed it...
  17. If you are going to service and clean the carbs properly that will require dismantling which will mean they are no longer set...hence will require a ( vacuum ) balance to reset.

    "some mechanics" are lazy and the stuffing around to set up balance gauges is too much for them...
  18. It's no secret that carbs certainly do go out of sync through regular usage. For example, my inline four was synced by a mechanic early last year. When I synced them again last week the vacuums were way off. Performing the procedure solved the rough idle that had developed.
  19. As far as I know carbs are synced via a carb sync screw. All this does is change the throttle opening on each carb to produce equivalent suctions/pressures. If its a screw then after a long while riding it can easily loosen up, or somehow change the balance.