Over the years I have seen the same couple of questions asked over and over again by just about every new Across owner.
In this post, I will try to cover these common problems and hopefully help get your Across back on the road, running nicely.
The things here are listed in order of complexity/difficulty.
Battery - may appear ok with lights illuminating normally, but “nothing” when pressing the starter. This is because the battery will carry near-normal voltage, but will not hold enough current to power the ignition circuit.
- Most Acrosses are now pushing 15 years young, and there's a good chance the battery has not been changed many times during the bike's life (if ever).
- Since an Across is often ridden by learner riders, the battery gets more use than a non-learner bike (new owners showing off their new bike by starting the engine, stalling frequently while learning clutch control, etc).
- Once a lead acid battery is fully discharged, it will not hold charge properly again (unless rebuilt; which is not possible with the Across sealed battery).
- A replacement battery should cost between AU$50-AU$150; once replaced you can eliminate the battery from any other problems the bike may have.
Idle Mixture Screws - vibrate loose (rich) over time. The bike will run too rich at idle (~0-3000rpm). It will start from cold with little or no choke, and may “bog down” if left to idle once the engine has warmed up. May also be difficult to re-start after stalling.
- The idle mixture screws are 4 flat-head screws on the top of the carburetors.
- They control the air/fuel mixture in the low rev range (0-3000rpm) of the carburetor circuit. The effects of these screws at higher revs is negligible compared to the other mixture controls (needle and main jet).
- These screws vibrate loose over time and enrich (more fuel) the air/fuel mixture.
Throttle Slide/Piston Holders - hold the throttle piston/slide to the carburetor diaphragm, in-turn hold the throttle needle in the piston. These wear over time with the movement of the piston/slide in the carburetor and allow excessive movement in the throttle needles.
- Small white plastic clips inside the carburetors.
- Stocked by most Suzuki dealerships as common spare parts; approximately AU$5 each. The Across requires 4 (2 per carburetor, 1 per cylinder).
- In an emergency can be "jammed" in place by wrapping the "clip end" with some kind of tape (inert teflon tape is best, but anything will do in an emergency).
- MANY Acrosses have these super-glued in place... this is not a good idea as the needles and pistons require some small movement to avoid the needle or main jet being damaged.
- When very worn, the entire piston & needle may be "dropped" from the diaphragm; effectively closing all fuel supply to the corresponding cylinder. This will be felt as a sudden loss of power, but the engine will continue to run. Seemingly at "half power". This can be fixed using the above emergency method. OR...
- It is always a good idea to carry some spare throttle slide/piston holders in the boot of your Across. They're tiny, cheap, and you never know when you (or a friend) will need them.
This post is a work in progress. Planned additions include; bold headings will be links to other posts with detailed information, photos to identify components, section for “dirty” carburetors, section for incorrect float height settings, section for worn high-tension spark plug leads.