Honda BF80A idle adjustment/hour meter problem

Hi all,

I renewed my Honda BF90D a few weeks ago with a new Honda BF80A, however I've noticed that the hour meter wasn't clocking up the hours correctly. I have now noticed that the 80 idles a lot slower than my 90 did (750 ish as opposed to around 1000), and while out fishing yesterday noticed that when idling between drifts the volts on the fish finder were dropping down from the usual 14.3V to around 13.5V, as though the charging is dropping off, when this happens I noticed that this is when the hour meter on the Tacho starts behaving funny, ie:- not flashing every six seconds or so, I either get a few quick flashes or none at all. I noticed though that if I increase the revs with the fast idle lever to around 800-850 both the volts stabilise at 14.3V and the hour meter heartbeat returns to normal. I'm wondering whether either there's a bad electrical connection to the hour meter or whether the engine is just idling too slow and the charging system is either dropping out or just going to a lower output. I have not looked under the cover yet but am wondering if there is any way of increasing the idle speed by means of an adjuster screw or is it a case of adjusting it on the cable itself?

Thanks in advance,

Topcat

Idle speed is fine,leave alone or if you're worried,get your dealer to check the hours using DrH to confirm your hour meter is correct when you have the first service done.

Hi Ian, thanks for the reply! It was the first service when we picked up on it, I asked the Main Dealer mechanic why he’d wrote 35 on the replacement oil filter and he said that’s the hours that are on it ( from Dr H), I said that’s strange the Tacho Hour Meter is only showing 22.7, so that’s what made me take particular notice yesterday when I was out fishing. I’m not overly bothered about the voltage dropping on tickover but would like the hour meter right as I use this religiously for 100 hour services. It could well be either a dodgy tacho/hour meter, or more likely a dodgy connection in the loom between remotes and meters. The Tacho was brand new with the new engine but we used the old shorter harness to the gauges as these didn’t come with the new engine for some reason. I’ll try a multimeter next time I’m on the boat to see what sort of voltage I’m getting to the tacho on tickover/ with revs on, just seems strange the fish finder is showing less volts on tickover as this is fed direct from battery. I woulda thought as long as hour meter was seeing 12 volts it would still clock up the hours correct,

Regards, Topcat

The tacho only clocks hours when engine is actually running, signal comes out of ECU so I wouldn't fiddle too much. Being out of whack the dealer should have attended to it under warranty at the first service. With regards to harnesses, they should be standard in the rigging kit, if not I would be asking the dealer why.

Just another thought, if you're insistant on accurate hours, why don't you make use of the NMEA data cable to a compatible sounder, this will give you the same reading as the diagnostics?

I thought about that but don’t you need the full length backbone thing with all the connectors, tees and end pieces etc? I’ll maybe look into that more as I would definitely like access to the fuel burn/totaliser info as I currently use a Faria flow computer which sadly are obsolete now, as are the Navman Fuel 3100’s. I’m running a Simrad NSS9 evo 2 which the NMEA will happily talk to so it could well be the way forward, but as regards the hour meter itself I’ll pass that back to the dealer like you say, especially as the engines brand new.

All you need for NMEA is a starter kit comprising basic back bone with a power feed, no big deal if you already have the head unit