Runs & started fine hot or cold last 10 years, in April replaced Pipercross open air filter with pipercross air box/ filter combi to get induction
DBs down for spa & the ring. Gave it the beans & Engine behaved flawlessly at spa/ ring where temp got up to sunny 17 degrees.....however ever
since I've been having hot start problems? Have I overcooked something I ask??
Symptons...when engine is hot like after I've filled up with fuel or I've left it standing for 10 mins after a blat it's a real bitch
to get going, sometimes will catch & fire up really reluctantly using plenty of right foot peddling or if battery exhausted I have to get out
& bump start. Starts fine if I let it cool down for a couple of hours or when it's cold then it just needs a little choke in this hot weather
to start 1st time. Fitted new battery, coils, HT leads, plugs....battery charging ok. Honda Fuel pump seems to prime & run ok. Fan kicks in as
normal & gauge indicates nothing abnormal. No hiss when I open up fuel cap indicating breathing ok. Carb bowls drain ok, only thing is it is a bit
lumpy on idle which I suspect carbs need synchro. Oil press seems lower than normal so maybe I have over cooked it but no excessive smoke of any kind
out of exhaust & engine still pulls like a train, oil consumption still frugal, plugs normal tan colour however when cold I pulled all ht leads
& turned engine over I expected to see wet plugs but didn't?? Fitted leads again & started ok???? ... I now dread filling up for
petrol....Plse help anyone
Hi,
Ive got an 89 cbr1000F engine in my haynes roadster, and I had the same problem, I'm putting it down the the engine been old/tired and having low
compression (about 25k miles on the engine) I put a MotoBatt battery on it with a bit more cranking power and trimmed the ends of the HT lead as mine
were a bit knackered and it seems to work for now.
have you tried going back to your old air filter/airbox setup, might be abit lean at tickover or something?
Regulator/rectifier problems? Seems to be a common Honda fault..
Dynojetted so carbs have been up jetted, motobatt is fitted & did oil & plug change when got back to UK, would burnt valves make it difficult
to start when hot? But no smoke or noise, oil & fuel & coolant consumption ok
& has PC fan blowing on cbr1000 reg/rec, battery is charging, fuel pump runs ok & starts from cold ok?
andy bates, where are u....lol
[Edited on 18/7/14 by andyfiggy2002]
Have you done a compression test?
Haynes manual will tell you the limits, do the test WOT rules out valve cylinder problems then? Halfrauds normally have the kits in for 20/30 quid
Mine does almost exactly the same thing, but switching the ignition off then on, it fires up straight away
Would low compression make it hard to start from hot but not affect performance or cold starting?
& I assume ignition switching trick is turning fuel pump on/off therefore giving a bit more pressure?
quote:
Originally posted by andyfiggy2002
Would low compression make it hard to start from hot but not affect performance or cold starting?
& I assume ignition switching trick is turning fuel pump on/off therefore giving a bit more pressure?
No smell of fuel but sometimes I get a backfire when I've struggled to start it hot, self regulating fuel pump on its last legs maybe?
I bet it's the fueling being thrown out by the new induction set up.
Return to old set up, if it's sorted get the carbs set up again.
You could try a pump and igintion switch but nothing's been changed there so seems strange.
Mine was running mega ritch with a differ t air box on, rejetting and correct air correctors sorted all starting running issues.
And more power! Worth a try.... Might be running leaner with differnt airbox. Running hotter, harder to start?
My ten pennies worth.
When I removed the original filter on my 893 it ran badly, doing the exhaust just made it worse until I fitted a dynojet kit which resolved things.
They can be very temperamental to start, filling the gap on the plugs helped mine, have a google you file the tang so it only covers half the
electrode which provides a less shrouded spark.
Duff plugs will stop them dead.
That's annoying, I stuck pipercross air filter back on & it has cured the problem I guess a bit like having a winter & summer setting on your air filter on an ordinary production car, spa/ ring in April was 1 degree at night & 17 degrees during day so not as hot as it is here in UK this humid summers day. oil press gone up to which is a bonus. So any ideas how I can use this air box in summer to quieten down induction noise considering I've got 132 jets in already or can I only use it during winter?
quote:
Originally posted by andyfiggy2002
That's annoying, I stuck pipercross air filter back on & it has cured the problem I guess a bit like having a winter & summer setting on your air filter on an ordinary production car, spa/ ring in April was 1 degree at night & 17 degrees during day so not as hot as it is here in UK this humid summers day. oil press gone up to which is a bonus. So any ideas how I can use this air box in summer to quieten down induction noise considering I've got 132 jets in already or can I only use it during winter?
have you checked the valve clearance
Ok comments noted & appreciated guys