GB Bikers Forum
General Chat => General Bike Chat => Topic started by: Nagasaki on August 13, 2023, 03:23:26 PM
-
A few months in and my YBR has developed an issue.
Its fuel injection so I dont know if the bike has some kind of auto choke but that seems to whats gone wrong. maybe?
It will not start 90% of the time on the starter, I have to kick it and even then it will turn over a few times, die. rinse and repeat a few times and give it a very VERY tiny 1mm of throttle and it will slowly rev up and run. The idle is very low 600-1000 ish but it usualy sits at 1500.
Once its running off the kick, I can use the electric start and all is well. Bike seems to run fine otherwise.
I just did a rather long trip from Peterborough to Chester and then Chester to Manchester and then back to Peterborough again and the apart from this issue, that started the day beofre my trip... its been fine. Any ideas what might be up with it?
Thats a cool 550 is miles done over 3 days.
My bum is still numb. lol
-
I'd check the state of the spark plug first.
What's the mileage? It may be worth doing the valve clearances, if they're too loose you may be struggling to build compression.
-
I actually fitted a new plug a day or 2 before this issue popped up.
A quick, finger in the spark plug hole compression test showed that its fine. Pushed my thumb out.
Valve clearances where checked recently and was fine.
Mileagle is about 10k
-
It could be the new plug is a duffer if it only started after it was fitted? Could just be a coincidence but check where the plug cap joins the HT lead as these can get disturbed and make a poor contact when removed for a plug change. Good luck with it.
-
Started up fine today, maybe it just don't like the north lol
It did stall a few times while out but that could be a wet hot lead from the rain....
How random.
Might get another plug just to try it.
-
Fuel pump or clogged filter possibly. May be worth a fuel pressure check.
-
They are known for crap HT leads/caps and shorting the to the head in the rain.
Mine was a pita for it, I live in Wales - how often do you think I rode it in the dry? lol
10k - the original plug should be fine for a fair bit more mileage than that, unless there was an underlying issue meaning replacement was needed.
-
Pull the HT lead and check the condition of the contact inside te rubber boot. It's not uncommon for them to get fuzzed up.
-
I put in the old spark plug and the issue persists.
Everything checks out with the plug and HT lead.
The issue is just on the first cold start.
Once its ran even for a few seconds it will start on the electric starter. Makes no sense to me.
Its kind of intermitent as well, The other day It started right up and then later on that day I had to kick it over to get it going again.
Bloody thing :bang:
-
This is still an ongoing issue and with the cold weather its much harder to get started.
The issue is clearly some sort of choke issue. If this was a carb thats what Id be looking at but its not.
So, what part is responsilbe for "choking" on this to help start when its cold?
In the image, the electronic device on the left side is the throttle position sensor but what is the thing on the top? I have no idea and cant find this part on ebay or google to get a name for it. Ill keep looking though.
-
The black connector on the top looks like a simple power supply, probably for the fuel injection pump ? Most fuel systems run a 'fast idle' as you can't just dump fuel in any more for the emmision regs. You may have an issue with the injection not setting enough fuel into the system until after it's started, not before it's started? Gusessing now mind...
-
Isn’t that the injector,any part numbers on it ?
-
That's a combined intake temp and manifold pressure sensor, I guess the injector is in the head or between the head and throttle body. I'd look at fuel pressure and possibly this sensor. I had weird issues on my Robin that pointed at fuel or ignition system. Swapped coils, leads, plugs, throttle body, ECU and the entire fuel supply system. Even after swapping in another engine it still gave me trouble. Turned out the lambda sensor was crusted up but only gave issues when cold, a time when the lambda reading isn't even used. EFI is a bitch to diagnose without reading fault codes and live sensor data.
-
The part circled is the stop solenoid.
(https://i.ibb.co/FBWbgKH/61f-En-KBfkg-L-AC-SL1500.png) (https://imgbb.com/)
-
Well, I got my hands on another throttle body and the issue persists. But it does not seem as bad this time.... but that might be due to being able to adjust the idle screw this time.
Ill know more tomorrow after the bikes been sat and is cold.
-
Sounds like you're getting close to the problem if nothing else. Keep plugging away :thumb:
-
I have a 2005 CBR125R Repsol with under 7k miles on the clock up for sale if you're interested? Just need to pop an MOT on it.
-
The saga continues.
I have still got this issue and its been narrowed down to the fuel enrichment curcit. It's supposed to tell the injector to give more fuel when the engine is cold.
There is supposed to be a temp sensor somewhere that tells the ECU to inject more fuel when its cold. This is not working it seems but not entierly sure how to fix it. I did have the ECU out today and there was a little corrosion on the pins and connector so maybe thats the issue. I cleaned it up best I could but mabe I should grab a spare ECU and try it. They are only about £15-£25 on ebay.
I'm slowly getting closer to just loading a parts cannon at this bike and hope it fixes it :whistle: lol
-
Trial and error, it's slow but it works :thumb:
-
Blimey It will be like a new bike 🤣
As NorthumBryan said Trial & Error good luck 👍