Have not changed fuel or checked spark plug leads as yet, just purchased bike only took bike for short ride i could feel the bike missing but thought that if the bike had been stored for sum time that it was not any thing to worry about any ideas on problem would be really great many thanks. GREG SMALL
I have just rebuilt the carbs on my buddy's Bandit 1200 that had a similar problem. After doing the initial checks to confirm it was not plugs, wires or coils and doing a compression test it came down to the carbs. After removing them and taking the float bowls off I found lots of small rubber pieces in the bowls. This could only have come from the rubber fuel hose, from tank to carbs, as there is a filter in the fuel valve in the tank and that was clear. The small rubber pieces had blocked off some of the jets. Apparently Suzuki recommends replacing that hose every two years. I suspect alcohol in the fuel was eating the inside of the hose.
i am not saying that is the same problem you have but something to keep in mind. If it had not been stored with fuel stabilizer in the tank I would drain the fuel and add fresh gas and then if the problem persists do the basic tests first before going further.
SOURCE: Backfire
Well, without physically hearing the noise it's a bit of a guessing game. However based on your description and past experience (all of which is from my past life as an auto tech of 23 years) it sounds to me like it may be a fuel problem, probably lean; generally a spark related misfire will occur more under load than steady state and a rich fuel condition will typically lead to bogging, while a lean condition is likely to cause misfires. I don't know if your bike is fuel injected or carbureted but judging by the vintage I'd guess it was carbureted. I'll assume that the engine runs fine under full load acceleration. You may have a carburetion problem (do you have single or multi carbs?) possibly a weak fuel pump although that would tend to show up more under heavy load than steady cruise or even over advanced timing causing detonation. I'm not sure of the specific systems on your bike so I can't offer any advice on how to check timing or examine the carb(s), but I can offer general procedures that may be helpful. Assuming again that you have carbs and a manual choke system, you could try putting a little choke on when the problem occurs to see if the problem goes away, if so this would prove the theory that the engine is running lean. One other thing I would do is to look at the plugs that came out of it (hopefully you saved and numbered them) and then pull the new ones back out and examine and compare them. Perhaps you could take some good pics and post them for us to look at and offer opinions on their condition and cause? Can you duplicate the problem in neutral? Is it only occuring at one particular road or engine speed or any steady speed? Does ambient temperature have any effect?
SOURCE: misfiring at speed on gilera 200 scooter
This sounds more like a lean fuel condition than ignition. If it was stored over the winter without the gas being drained or a fuel stabilizer being added, you'll likely have varnish build-up in the fuel system that is not allowing sufficient fuel flow. If your engine is fuel injected, it's likely your injector is partially clogged. If it's carbureted, your carb jets may be partially clogged or your carb float may be sticking and not allowing the needle valve to fully open. Fill the gas tank with fresh gasoline, but leave enough room for a can of Sea Foam. The Sea Foam may be able to break up the deposits and allow fuel to flow again. However, there's no guarantee and the fuel system may have to be disassembled to be cleaned.
SOURCE: Misfiring 2007 Honda VFR 800
I would say that your bike may be running a little lean. I usually replace the jets on all my bikes as soon as I get them as the emissions requirements mandate that the manufacturers pass stringent emissions tests prior to the dealer selling them. Some bikes wont even idle or run, especially off road bikes from places like California. and in these cases you must re jet it is a must! I even throw away or drill larger holes into my air cleaner cover.
Good Luck!
Geodesygold
239 views
Usually answered in minutes!
×