Well, thought I'd put this into its own thread finally. As you may know, since picking up a bad batch of fuel back in April or so, my 1402 has not been running right.
Last summary / update was:
Update on Bilbo: seems I have walked through the gates of Mordor...rechecked everything i had done again just to be sure. Talked to a few places, including wreckers re a new ECU, all said they dont have any, and were surprised if it was the ecu at all. Bloke in SA said highly unlikely, as then youd have no running or rough running at all rpm, which is not the case here.
So I checked STPS (replaced with genuine new last year) this time at the connector and removed air filter to move them to check resistance. Turns out it was giving 2.9kOhm open and 0.8 closed, the latter being to spec, but the former should be 3.9kOhm according to the book. So I adjusted it, but its maxxed out at 3.3kOhm open and 1.1kOhm closed. Cycled the ignition and it showed 3.6kOhm, close enough to the required 3.9kOhm for now. Also cycled through closed to full throttle 3 times, then fired it up, still runs rough, but admittedly it hasnt run for about 3weeks, but seemed better. Let it warm up, and the stva worked for a bit so that was good. The backfiring was not as bad either.
Ran out of time tonight but will take it for a ride again later this week to see what difference that has made, so fingers crossed, not quite at Mt. Doom yet....
Might have to file out the slotted holes in the STP housing to get to 3.9kOhm if that has really made the biggest difference.
Fingers crossed..."
The cause is:
- contaminated fuel, most likely water in the fuel, or stale fuel.
The symptons are:
- rough idle and poor starting, takes 2 or more goes of the button and need to hold throttle open a bit.
- when idling at ~1100rpm, opening the throttle causes stumbling and hesitation, pops though the exhaust and smells of unburnt fuel, sometimes it stalls.
- over about 3000rpm it smoothens out.
- uses a lot of fuel, std is around 5l/100km, last time i rode it it was around double that.
- had rust in the tank, all cleaned out, including fuel rail, pump and new injectors (see below)
Bike is basically un-rideable, opening the throttle it bucks and hesitates, until ~3000rpm, rolling off the throttle it backfires and pops, not smooth at all. Closing the throttle, the revs stay high for a bit.
So now I'm going to list all the checks I have done to date, all checks against values in the Suzuki manual.
- new spark plugs, with the old ones 1 out of the 4 tested at 16kOhm, the other 3 at 6kOhm (ngk spec).
- throttle cables lubed and snap return checked, all ok, cable tension to spec, not interfering or catching on anything.
- new MAP, genuine Suzuki ex Webike Japan
- new stator and signal generator as magnet on the old one was broken
- TPS replaced about 18 months ago with genuine, setting as per manual 1100 Ohm throttle closed
- STPS replaced about 12 months ago with genuine, setting now correct at open at 3900 Ohm, was 2900 Ohm open. Closed is now ~1200 Ohm which should be 800-900 Ohm, but I think the open setting is more important
- IAT - ok
- IAP - ok
- TOS - ok
- EOT - ok
- CKP (crank sensor, part of new stator) - ok
- CMP (camshaft sensor) - ok
- injectors - replaced with new (ebay, same part no as Bosch oem) suitable for engines up to 2000cc, matching connectors etc. New seals
- coil packs - ok
- ht leads - ok
- battery - SSB lithium, new
- compression tests ok, 165psi each pot, cold
- valve clearance, all within spec at 56000km.
- efi pump (quantum aftermarket), cleaned out teabag, external hp filter and fitted new inline lp filter as well. Flow rate is 1300ml/min, spec is 1200ml/min, pressure unknown, but reg seems ok, replaced with the old one for the time being.
Next things to check:
- smoke check for any cracks or leaks, can also use carb cleaner around intake when running as suggested
- exhaust leak at header exiting block
Failing that, do I need to look at burnt valves, or retiring the engine?
I'm open for ideas, I don't want to retire or break the bike, I'm sure it can be fixed, just need to find out what is causing this rough running...
Started it up yesterday after putting thr rebuilt efi pump back in, no change.
Will also work out a way to check fuel pressure (cheers Grog for the reminder)
Eric, are you on any non-14 forums? Although there's been plenty of suggestions on here, I wonder if fresh minds may come up with something if you describe the symptoms...they won't be limited to the 14.
Just a thought.
Failing that, know any really good bike mechanics?
I can't see it on the list & can't remember if we've suggested it.
Clutch switch? if they stick on the starting circuit etc works fine, but it'll be running a different fuelling & ignition map. I know when I bypassed mine as a temp measure years ago it'd backfire twice every time I gave it some throttle & sounded like someone firing a shotgun behind me.
Thx, so other things to check now (adding to my list)
- pairs, even though checked them twice already
- TRE thats been fitted for ages, will take it out of the loop and see if any difference
-timing, when i checked the clearances, the marks were not as per manual, but cam lobes were correct for checking clearances.
- clutch micro switch
Eric, just been reading xdiavels post, couple of things seemed to pop out, You have a TRE fitted & I think I once read Bilbo has a full Akra exhaust. Pretty sure I recall
@seth saying if you go full Akra exhaust you need to have the bike tuned. Could be the combination of the TRE & Akra that's giving you the issues. PC-V & Autotune, else take it to a tuner.
Quote from: KiwiCol on Friday, 21 November 2025, 05:02 AMEric, just been reading xdiavels post, couple of things seemed to pop out, You have a TRE fitted & I think I once read Bilbo has a full Akra exhaust. Pretty sure I recall @seth saying if you go full Akra exhaust you need to have the bike tuned. Could be the combination of the TRE & Akra that's giving you the issues. PC-V & Autotune, else take it to a tuner.
The number of folk still don't get it these bikes need a remap if any fueling is changed
Some get away with and endcan swap but anything more needs the fueling adjusting in some way.
Cheers guys, yes it has an Akra 4 into 1 and a TRE. The exhaust was on it when I bought it 6 years ago, and I remember seeing a service invoice (that i can't find now, even though i have the original delivery booklet and receipt from 2003) that included an ECU flash tune. Bike has been running fine up until I got some dodgy fuel in it.
Will remove the TRE from the circuit and test.
Quote from: Pommeroy on Thursday, 20 November 2025, 04:17 PMEric, are you on any non-14 forums? Although there's been plenty of suggestions on here, I wonder if fresh minds may come up with something if you describe the symptoms...they won't be limited to the 14.
Just a thought.
Failing that, know any really good bike mechanics?
yes, I've been talking to my BMW mates and I'm lucky, my neighbour and friend is also a mechanic.
Well, for the bad gas, I think you've put in a new HP pump & filter & new injectors, so all that's left is the fuel line & fuel rail. Can the rail be back flushed / cleaned out internally in any way? New fuel lines shouldn't be a problem or just check they're not restricted.
If you have the original HP pump & filter, have you done the HP filter bypass? if not, Bilbo may be a good candidate for it.
Thanks Col,
Yes, rail cleaned out, hp filter bypass done a while ago, works well, just cleaned it out again on Sunday as well as the internal in-tank hp filter that is bypassed. Lines after the filter are free and clean. This weekend will be checking for air leaks.
I did notice last night that the header pipe for #1 is sitting very close/touching the lh frame tube that has the compliance plate on it, hopefully that hasn't rubbed through, the Akra is very thin wall tube...
You and Xdiavel bikes,just dont make any sense. I try to figure. Thats how ive paid my bills forever, fixing motors. These 2,just not playing a normal game😡😡
Will get to the bottom of this im sure. Header pipe on #1 and frame tube
20251121_175245.jpg
Well, compliance plate hasn't rubbed through the #1 header pipe...yet.
20251121_181732.jpg20251121_181740.jpg
Took the exhaust headers off #1 to #4 and had a peek inside the exhaust side.
I'm no expert, not sure what the white stuff is, all I know is black = rich, grey = lean, brown = good. Can't see much brown, but lots of black and very light grey.
Cylinders 1 to 4 in photos below
20251121_181400.jpg20251121_181417.jpg20251121_181442.jpg20251121_181500.jpg
Edit: looking at the valve stems, they are white, will try a closer look inside tmrw and swap injectors.
No leaks around the exhaust, in that no soot etc. Will give the exhaust side of the block a good clean, and polish the headers for a bit of being, might make her behave
That rubbing is probably just a badly fitted exhaust. Mine was rubbing the sump before I got it & years later I had a leak when the thin bit of the sump cracked. I bit of slackening & jiggling got more clearance. So I'd expect you'd sort that as you refit the system.
Well, to continue the LOTR mash up, it seems Middle Earth is saved once again.
So today was shed time after working diligently through SWMBO lists and the usual grocery chore.
Efi pump was back in the tank and cleaned.the target was swapping the old injectors back in and befitting the Akra exhaust. Swapped old injectors back in,using the new o rings and seals, plus a dab of ht grease on the seals to ensure they slid home in the throttle bodies. All done, then I got excited and fired it up, admittedly forgetting I had no headers of muffler. The noise was quite frankly LOUD, like Mt Doom erupting when Frodo and Sam descend after Gollum falls into it with The Ring. Woke up the dogs and I think everyone wlse in a 3 block radius. Interestingly, it idled at 3000rpm and no miss, backfires etc.
Then spent sone time polishing and befitting the header, 2into1 splitters and end can, came up a treat BTW. Fired it up,started first go and sat at 3000rpm. Turns out the hand idle was wound in, so undoing that slowly, revs dropped to 2000, then 1500 then settled at 1100 rpm and no misfire, pops or stumbling off throttle. Let it warm up then did some revision pulls to 6-7k, sweet as, settled right back down to 1100rpm.
I call that a fix, I think the 40aud injectors, the msladjusted stps,new map and broken stator signal magnet all played a part.
Ran out of daylight, will take it for a run tomorrow.
For now all is good in the Shire....
Excellent news, that sounds very promising.
Btw way with all the LOTR references I first read it like this...
Quote from: Eric GSX1400K3 on Sunday, 23 November 2025, 09:32 PMElf pump was back in the tank
Which gives some strange images.
Eric,was that first time changing injectors back since running poorly?
Quote from: grog on Monday, 24 November 2025, 11:19 AMEric,was that first time changing injectors back since running poorly?
yes, but after changing MAP and Stator plate, new plugs and resetting the STPS.
Last time I buy cheap injectors off Ebay I think
Think theyve caused you a lot of grief and def not saved you money. Primary reason for your dilemma me thinks.
Yup, even though the part numbers matched, connectors and seals etc all fitted they were rubbish. I binned them today.
Yeah Mate,ive had some great wins on ebay, just a couple of failures. Its a bit life in general, some you win, some just a face kick.Next episode is the important one.
All done, then I got excited and fired it up, admittedly forgetting I had no headers of muffler.
Probably just gave it the best valve job Eric :onya: (used to do it on the old Trumpets)
Well, two rides in since running right again and happy to say it rides like it should. Did some tooling around the 'burbs, idles and behaves well. Then took it 'out back' and did a few runs of 0 to ~100mph (160kmh) clicking through the gears like a tap dancer on opening night, revs free to redline and still pulls like a train. Blew out the cobwebs for sure
Happy days.
One thing I have noticed though is the drop into 1st gear when standing still. Might be the oil needing a change (due end of Dec) or perhaps the slave cylinder needs a look at. Was trying with the idea of fitting an Oberon slave, they look very well made...
Great news Eric.Dirty fuel initially but crap injectors caused all your work.IMO Change the oil, bleed your clutch, they all clunk into first.Spend your bucks on fuel😎
Cheers Grog, always the voice of reason on here.
Sounds like you've fixed it Eric, bet you're relieved!
Re 1st, yeah they all do that. But a strip & clean of the slave never hurts as they do get gunked up with chain lube & crap thrown off the chain. Clean the push rod too, it just slides out. Just make sure it goes back in the same way so any worn/pitted/corroded surface doesn't wear the seal inside the engine.
I always give the front sprocket a wobble when in there too, as I've occasionally seen them come loose. They never seem to come off as the speedo trigger holds the sprocket nut on.
Cheers, will do. Bite point seems a bit further away than I'm used to, action is still nice.
That'd make sense with a sticky piston not sliding as well as it should then. There's a mod on here somewhere with a Busa part to fit a rubber boot over the slave & solve the problem for good.
I avoid clunking into 1st gear by holding the clutch in for a count of ten, this allows the clutch plates to free up and then 1st gear goes in with a click. ( after letting the revs return to idle from cold start obviously.)Anybody else do this??.
To be honest 90% of the time mine was started in gear anyway. I always parked it up in gear as it's a little more secure if knocked or on a slight slope. The only exception was in the garage where I'd wheel it in backwards for a more sensible parking position.
Tally, never tried but i will.
Quote from: Tally on Thursday, 27 November 2025, 01:05 AMI avoid clunking into 1st gear by holding the clutch in for a count of ten, this allows the clutch plates to free up and then 1st gear goes in with a click. ( after letting the revs return to idle from cold start obviously.)Anybody else do this??.
yeah that is supposed to overcome stiction and separate the plate stack. Suzuki clutch steel plates are dimpled to retain more oil, plus the clutch sits in an oil bath.
The 10sec count is common practice with the dry sump/wet clutch BMWs, as oil gets pumped into the stack only when the engine is running.
I tried it with the 1402 but made no difference. Held it for a count of 10, then dropped it into 1st. Bike lurches fwd and its a big clunk. Not healthy for the gear engagement dogs. Away this weekend, but will strip the clutch slave down, change fluid and go from there at the next opportunity.
Dont think ive ever owned jap bike that didnt clunk into 1st. Ducati, English etc, cant remember.Try a Harley, some of them scare me, almost think their fine handling frame could get damaged. 😂
I find it odd, some days bikes drop into gear smoothly yet another it's an almighty bang. Doesn't seem to be any logic to it either. Just life with wet clutches I guess.
Much better than dry clutch i built for mates Jawa. It lasted 30 ks then smoked up, scary. Master mechanic me, it was actually a wet clutch. Hard to be perfect all the time🤪
Quote from: Hooli on Thursday, 27 November 2025, 06:43 PMI find it odd, some days bikes drop into gear smoothly yet another it's an almighty bang. Doesn't seem to be any logic to it either. Just life with wet clutches I guess.
exactly, same here, and it doesn't seem to matter whether its hot or cold engine.
Does the name Bilbos have any relationship with Bilbao- Spain?
No Mate, we named it from Lord Of The Rings, such a long story to fix it👍
Quote from: grog on Tuesday, 02 December 2025, 05:09 PMNo Mate, we named it from Lord Of The Rings, such a long story to fix it👍
I think that is code for him being very short with big hairy feet. :whistling: :lol:
Tend to get the toe hair curled around the gearshift sometimes, but I digress....
Quote from: Eric GSX1400K3 on Wednesday, 03 December 2025, 10:59 AMTend to get the toe hair curled around the gearshift sometimes, but I digress....
Digress as far as putting some Brylcreem in said hair & comb backwards & hey presto, no more tangles in the gear shift! God, remember that stuff? Glad that's not still a thing.
Well, tell that to the guy at our gym that seems to swim in the stuff