CBF1000

CBF1000 => General Maintenance, Servicing, and Mechanical => Topic started by: alexg on 21 October, 2020, 02:34:38 PM

Title: Engine struggle to start
Post by: alexg on 21 October, 2020, 02:34:38 PM
After servicing my bike and installing back No10 and no11 springs "see attachment" (they was removed before by recommendation of service guy)
My MK1 A7 starter struggle to turn engine, i can hear it turning over but very slow, not fast  enough to fireup.
I can push start bike and it would run fine on any of the rpm.
Charging system works i can see 14v when driving.

I tried to connect to car battery, but no luck, it just starter motor struggle to turn.

Any one have an idea what it can be?

battery is about 3month old.
Bike did not have this issue before i reinstall springs back.
Title: Re: Engine struggle to start
Post by: Art on 21 October, 2020, 06:51:43 PM
The answer is probably in the question. Why was it recommended to remove the anti judder spring and what was the decision to re-install it based on? Will the starter motor crank and start the engine with the clutch disengaged?

Do you suspect this to be a clutch issue or a starter motor issue?

Will the starter motor crank and start the engine with the clutch fully disengaged?
Title: Re: Engine struggle to start
Post by: alexg on 21 October, 2020, 07:25:25 PM
"Why was it recommended to remove the anti judder spring and what was the decision to re-install it based on? "

-I had(and still have) issue with shifting gears, feels like shifting is not smooze and sometimes i don get proper clank when shifting. So service reccomended remove springs. They did that and checked clutch as well. this did not do any difference at all. Clutch is in good shape.

"Will the starter motor crank and start the engine with the clutch disengaged? "
-It will crank but wont start.
Today after bump starting and driving for a ~10min, i shut engine off, and tried to start again, it barely cranked, but did started engine, i shut it again, and was unable to start anymore.

Feels like there is not enough juse in the battery. Battery fully charged, and even with help of the car battery, feels same.

It maybe starter motor, but why it suddenly become 'weak' after installing those springs.

I tied rocking back and force with gear on, this did not helped.
Title: Re: Engine struggle to start
Post by: Art on 22 October, 2020, 05:16:59 AM
So you have two issues

1) Poor gear change - I assume when the service guy checked the clutch all the components were properly and thoroughly inspected, measured and found to be good and within specification tolerances. Although since he recommended removing the judder spring I'd question if he knows what he's doing. The correct procedure having confirmed the fault would have been to check clutch operation, engine oil and gear change mechanism.

2) Poor cold cranking - What say the service guy here or does he attribute this to the clutch!? The correct procedure to follow would be to confirm the fault, and then to check the battery (level of charge and cold cranking), check the battery connections, check the starter motor connections and circuit, check the starter motor no load operation, bearings, brushes and armature.

Title: Re: Engine struggle to start
Post by: alexg on 22 October, 2020, 06:19:52 AM
1) service guy checked the clutch all the components were properly and thoroughly inspected, measured and found to be good and within specification tolerances.
Short answer would be no. He just inspected clutch visually and took off springs.
"I'd question if he knows what he's doing." - cannot agree more.
So once they have been removed i used my bike for more than a year. And i got used to dodgy gear shifting. This issue never affected starting performance.

2) Poor COLD and HOT cranking.
After he put back springs and fresh oil bike could not start any more.
This guy blame my charging system, saying it is not charging battery enough. ( i dont understand hot it is related to starting performance if i trying to start with fully charged battery+car battery)
I suspected it maybe starter motor brushes or something in that area but not charging system. So we stuck in the loop charging system -> starter motor until he told me to f-off in polite way. That's were we are at the moment.

Starter motor circuit i will check this weekend. I have not touched it before or after this fault developed.

As for battery its only few month old yausa battery.
Title: Re: Engine struggle to start
Post by: Art on 22 October, 2020, 10:47:34 AM
You may need to start from square one with both your faults. Of course since the service guy has thrown it into the mix you may as well test and eliminate the charging system just in case he's onto something. Its easy enough, with the engine running at 5,000 RPM check the voltage across the battery terminals, expect 13.5 to 14.5v. It could also be sensible to think back to the time when the motorcycle was running as it should and then to list and check all the things that have been done to it since. For example the removal and re-fitting of the clutch judder spring and that new Yuasa battery check the fitment (YTX10S), the level of charge and cold cranking. Here's the plan and its the only plan, there are no magic wands here or short cuts.

1) Poor gear change check in order - clutch operation, engine oil and gear change mechanism.

2) Poor cold cranking check in order - the battery for correct fitment, level of charge and cold cranking, the battery connections, the starter motor connections and circuit, the starter motor no load operation, bearings, brushes and armature.

Assume nothing, check and test everything.
Title: Re: Engine struggle to start
Post by: alexg on 22 October, 2020, 01:16:19 PM
*Originally Posted by Art [+]
You may need to start from square one with the engine running at 5,000 RPM check the voltage across the battery terminals, expect 13.5 to 14.5v.
I will try to start from the beginning. I checked voltages and @1500 i get 13.6, @5k - 14.7
Can cross out charging system.
 

*Originally Posted by Art [+]
It could also be sensible to think back to the time when the motorcycle was running as it should.
Only clutch judder spring was installed, and fresh oil+filter

*Originally Posted by Art [+]
1) Poor gear change check in order - clutch operation, engine oil and gear change mechanism.
Clutch operates smoothly did not find any issue when mechanic opened it last year. I did not check gear change mechanism its quite involved job, i think there is may be some problem causing shifting be bit sticky/difficult.
But it did not cause me starting up issue.


*Originally Posted by Art [+]
2) Poor cold cranking check in order - the battery for correct fitment, level of charge and cold cranking, the battery connections, the starter motor connections and circuit, the starter motor no load operation, bearings, brushes and armature.
- Battery checked, in good order and terminals are tight.
My next to do to check starting relay and after to take starter motor out.

Title: Re: Engine struggle to start
Post by: Art on 22 October, 2020, 04:08:45 PM
With the engine running at 5,000 RPM and the battery voltage reading 14.7v you have to wonder why the service guy would suspect the charging system! The gear change and engine cranking are two totally separate issues. Checking the gear shift mechanism can get involved and run into a full weekends work and then some. All you need to do to check the starter relay is to listen for the click when pressing the starter button then again if the starter motor is spinning, even slowly, the starter relay should be good.

Before pulling the starter motor check the starter motor connections and the main 30A fuse terminals are all clean and secure.
Title: Re: Engine struggle to start
Post by: alexg on 23 October, 2020, 10:10:51 AM
*Originally Posted by Art [+]
With the engine running at 5,000 RPM and the battery voltage reading 14.7v you have to wonder why the service guy would suspect the charging system!
I doubt his electrical knowlege. As he sayed car battery CAN damage electics on the bike.

*Originally Posted by Art [+]
Checking the gear shift mechanism can get involved and run into a full weekends work and then some.
Im trying find time to look into, hard job to do it by myself without access to the garage.
*Originally Posted by Art [+]
Before pulling the starter motor check the starter motor connections and the main 30A fuse terminals are all clean and secure.
Will do that this weekend.
As per manuals, there is no way to take starter motor out without removing airbox.  :087:
Title: Re: Engine struggle to start
Post by: Art on 23 October, 2020, 12:36:40 PM
Take heart at least by tackling the work yourself you're not going to be hit for 70 hard earned for every hours labour.

 :211: Read the manual, understand each part of the task and take it one step at a time. A big plus in CBF1000 ownership is the ease in which it can be serviced and maintained at home by the home mechanic without the need of any special tools or diagnostic equipment.
Title: Re: Engine struggle to start
Post by: Shed on 23 October, 2020, 02:08:50 PM
*Originally Posted by alexg [+]
-I had(and still have) issue with shifting gears, feels like shifting is not smooze and sometimes i don get proper clank when shifting. So service reccomended remove springs. They did that and checked clutch as well. this did not do any difference at all. Clutch is in good shape.

So you had issues with gear selecting before your cowboy mechanic took the clutch springs out? Why would he do that?  :084: :087: :112:
What was the reason given for this?  :027:

As Art has astutely referred to, what's the state of play with your gear linkage? Assuming the other side of the clutch, i.e. from the lever, hose, slave, rod, fluid bled properly etc, was all working, did anyone bother to check the selector linkage before taking springs out? For example, in the pic check out the bolts numbered 15 - if these bolts come loose even by a few turns the smoothness of gear selecting can be effected as the linkage alignment can become wobbly loose. Also check to see if the washers numbered 17 are present, or if they've fallen out at some point, but haven't been replaced. Again, this will effect the alignment of the selector mechanism throwing out your smooth gear change. Was any of this even checked over first? Even now, it's worth checking/servicing the linkage assembly while you're down there.   :028:

That scenario has actually happened to me, with the sudden sloppy gear change just happening to coincide with a clutch bleed. At first I doubted myself and instantly thought I'd bled it poorly, but then thought no I didn't, and sure enough when I checked out the linkage it was ever so slightly loose. The absolute last thing on my mind would have been "Oh, I best remove the clutch springs". Wtf?!  :157:

Anyway, I removed the bolts, cleaned, greased, reinstalled with blue threadlock, job done, Smooth gear change reinstated instantly. Literally a 5 minute job.
This may not be your case at all, but always start with the easy & free stuff!

Title: Re: Engine struggle to start
Post by: Art on 23 October, 2020, 04:51:42 PM
For what its worth and I mention this only because it may be a common theme with the SC58 gear change pivot bolt, part 15 in the above diagram.

When my gear change developed a hit and miss engagement and false neutrals became more frequent knowing the clutch operation was good and the engine oil was not the cause I checked the gear linkage. What I found was there was a little play that could be felt in handling the pivot that was not noticeable with a foot gear change. The gear lever pivot bolt had stripped out part of the thread in the aluminium footrest bracket and was literally hanging on by no more than a thread or two. Resolved with a cheap as chips, 7.49 bargain M8 helicoil kit off fleabay. I'm not a fan of the red high strength Loctite 272 but for some applications needs must and I used it to install the helicoil. For refitting the gear change pivot bolt, which needs to be removed from time to time, the blue medium strength Loctite 243 was my weapon of choice.
Title: Re: Engine struggle to start
Post by: alexg on 24 October, 2020, 01:25:24 PM
I checked all wiring to the starter motor, its all good.
I checked resistance between + and - on the starter motor i get 0.02 ohm. 

I was unable to take starter motor out at this stage.
I definitely need to remove air box first.

To do so i need to buy long Philips screwdriver to undo clamps that holds air box with engine block.

here is youtube link you can hear how is starter motor sounds.
I checked linkages they seems to be fine, there is little play between assembly 14 and washer 17. About 0.5 mm in length. Same play distance on the arm(with screw 12) and engine block. Maybe i will do short video for clearance.


I think at this stage would be easier to check judder spring if they fitted correctly. I guess it would be easier that removing airbox.
Title: Re: Engine struggle to start
Post by: Art on 24 October, 2020, 03:15:02 PM
That sounds like a battery issue. I remember you said the battery was new but new batteries fail too, did you test the battery for Cold Cranking?

A typical cold cranking test checks the battery's amps while applying an electrical loading, this is not possible using a multimeter but you can check the cold cranking voltage drop which gives a good indication of the condition of the battery under an electrical load.

First check the battery has an initial level of charge greater than 12.5v, if less than 12.5v fully charge the battery before testing the cold cranking. Turn the ignition on, apply full throttle (this disables the Fuel System) crank the engine on the starter motor button for 5 to 10 seconds while checking the voltage across the battery terminals and noting how low the voltage drops. Expect the voltage to drop no lower than 9.5v which is borderline, 10.5v is typical and the nearer to 12v the better. Unfortunately this test is not conclusive and if the voltage drops below 9.5v then either the battery was not fully charged or there is a loose or dirty connection or the battery is at fault.

Don't forget you're dealing with two issues here cranking the engine and changing gear. Keep them separate, they will not be related or connected to a common fault.
Title: Re: Engine struggle to start
Post by: alexg on 24 October, 2020, 06:33:33 PM
I am trying to keep gears/starting separate. For the timebeing forget about gears, i mentioned that to tell why spring were taken out.
 i need to sort starting up first. That is my main problem.
 On the video above it does sound like the battery, but believe me it is not the battery. I have voltmeter attached to the battery while starting engine and voltage dropped to 9.6v when starting and back up to 12.5 once stopped.
I have to mention again, when i connected car battery starter motor kept making same sound while i was trying for 10-15 seconds to hold start. It did not start after all.

Bike was starting without any issue on cold or hot, before i put back judder springs.  :027:
Title: Re: Engine struggle to start
Post by: ivor hugh jarse on 25 October, 2020, 05:59:56 PM
a quick way to know if it is, or is not the battery may be to try jump leads - if it cranks over normally with the assistance of another vehicle you may be well on your way to solving it
Title: Re: Engine struggle to start
Post by: alexg on 26 October, 2020, 08:21:22 AM
*Originally Posted by ivor hugh jarse [+]
may be to try jump leads

I did that before, bike did not started. Did the same as on the video.
Title: Re: Engine struggle to start
Post by: Art on 26 October, 2020, 10:15:14 AM
Just a thought if it was exactly the same as in the video you may not have had a good connection on the jump leads, they often need a little wiggle on the terminals at all four ends.

Title: Re: Engine struggle to start
Post by: vinciebhoy on 26 October, 2020, 04:04:13 PM
I had the same fault on a car once, I used a jump lead to go from battery negative straight onto the engine and it worked ok. A faulty earth was the problem.
I have never had to work on the CBF starter before but could be worth checking the earthing points.
Title: Re: Engine struggle to start
Post by: vinciebhoy on 30 October, 2020, 12:44:15 PM
Hi Alex, have you found a solution to your sluggish starter problem yet?
 :003:
Title: Re: Engine struggle to start
Post by: alexg on 30 October, 2020, 04:45:03 PM
*Originally Posted by vinciebhoy [+]
Hi Alex, have you found a solution to your sluggish starter problem yet?
 :003:
Not yet, it was very busy week, i will work on the bike on the week end.
My plan for now, setup everything as it was when it was working. So i will take out judder springs out, to see if they were fitted correct way around.
After that would have to take starter motor out, to see if there is any problem.

Will keep you all updated.
Title: Re: Engine struggle to start
Post by: vinciebhoy on 30 October, 2020, 06:10:38 PM
I would defo try bridging out the engine earth first by putting a jump lead from the battery negative to the engine, if that doesn't work try this but be careful, make sure the bike is in neutral on the centre stand and put a jump lead on the battery positive then touch it onto the starter main feed, this will bridge out the starter relay switch.
Title: Re: Engine struggle to start
Post by: Art on 31 October, 2020, 01:39:04 AM
Jumper leads are a bad idea and the method described above does not test the connection all the way to the starter motor terminals so it is an incomplete check.

Remove the air filter box to get access and use a multimeter to test the voltage drop at the starter motor terminals before removing the starter motor. Select the 20v DC range on the multimeter, connect the black probe to the battery negative terminal, connect the red probe to the starter motor ground terminal and switch the ignition on. The lower the voltage drop the better, expect a reading of 0.2v or less. If greater than 0.2v suspect a poor connection. Disconnect, clean, check and tighten all terminals, connections and ground points.

The positive side is similar but more tricky since you need to have power in the starter motor cable. Connect the red probe to the battery positive terminal, connect the black probe to the starter motor positive cable terminal, switch on the ignition, apply full throttle to isolate the fuel system and press the starter button. Again the lower the voltage drop the better, expect a reading of 0.2v or less. If greater than 0.2v suspect a poor connection. Disconnect, clean, check and tighten all terminals, connections and the main 30A fuse.



Title: Re: Engine struggle to start
Post by: alexg on 31 October, 2020, 09:35:18 AM
I solved my starting now.

Thank you all for your great sugestions.

The issue was the judder spring fitted in wrong way around.
It was fitted like so / i put it like this \ and it solve the problem.
Title: Re: Engine struggle to start
Post by: vinciebhoy on 31 October, 2020, 10:51:33 AM
Well done Alex, good spot, turned out to be a mechanical fault after all.  :028: You can now let the Biffer put a smile on your face again.  :001:
Art I worked successfully as an Auto Electrician for 12 years in the day before throw away units, and the method I suggested is the quickest and easiest way to find out where the voltage drop would be if it was an electrical fault in a sluggish starter and not the starter motor. It is 90% going to be on the main line ie Earthing or Main positive feed but could still have been a weak solenoid or relay causing a poor connection on the main feed.
Once you find out what side of the main line it is on then you can use the voltage drop method that you explained which can be a bit daunting for a novice in electrics.
Title: Re: Engine struggle to start
Post by: Art on 31 October, 2020, 12:00:10 PM
 Happy Days

:087: I'm struggling to understand how fitting the judder spring back to front would add any extra load to the starter motor.

Not convinced by your "\ " that the judder spring is now fitted correctly. The judder spring should be fitted inside the first friction ring with its outer edge raised and facing out. If a picture is worth a thousand words a video is worth a sneak peek...


vinciebhoy - Back in the day at one time or another we all jumped starter motors with the likes of a big old bent up screwdriver, that didn't make it right. I stand by testing the cable/connection voltage drop with a multimeter connected between the battery terminal and the starter motor terminal for three good reasons - It tests the complete connection, it provides a meaningful test result and it is easier to get the smaller multimeter test leads on to the terminals vs the bulk of an 80 to 100A battery jumper cable. Its a fair point some may find using a multimeter a bit daunting. If that is the case it's a hurdle that must be overcome which is why I explained the method in such detail.
Title: Re: Engine struggle to start
Post by: vinciebhoy on 31 October, 2020, 12:20:40 PM
Art, I don't disagree with your electrical fault finding methods but what I said is the quickest and easiest way to find where the fault would be, then you get down to the detailed approach  :015:
Title: Re: Engine struggle to start
Post by: alexg on 31 October, 2020, 12:49:54 PM
*Originally Posted by Art [+]
Not convinced by your "\ " that the judder spring is now fitted correctly. The judder spring should be fitted inside the first friction ring with its outer edge raised and facing out.

That how spring was fitted inside first frictiong ring, flat washer and judder spring with outer side facing up. :027: like on the video (engine) |/ |||||::  (outside)

I reverse it to make inner side face up. |\  ||||||::
Probably now i did the wrong way around, but it did the job, and bike starting up now.

I dont understand how it did so much difference.

I did test voltage drop on neg and pos cables is was showing dead short on each 0ohm. Connection is good.
 It maybe starter motor brushes are close to the service limit, and this can cause weaker current flow.

Title: Re: Engine struggle to start
Post by: Art on 31 October, 2020, 04:28:49 PM
Happy Days

No worries vinciebhoy, horses for courses, I just prefer one test one test result.
Title: Re: Engine struggle to start
Post by: Shed on 31 October, 2020, 07:10:29 PM
So basically, you've resolved all your issues by replacing the judder springs that your mechanic took out?  :110: Is that right?  :084: :030:

All that time wasted doing utterly pointless electrical tests, and worrying about mechanical woes?  :172:

Get yourself a new mechanic my friend.  :028:
Title: Re: Engine struggle to start
Post by: alexg on 31 October, 2020, 08:19:40 PM
*Originally Posted by Shed [+]
So basically, you've resolved all your issues...

Get yourself a new mechanic my friend.  :028:

No sure about ALL. Will see how is gearbox will be. As i mentioned in the beginning it was bit sticky?, like when you switch gear with engine off, and you can see it switched but when you turn rear wheel it clicks further in.

 Same feel but while driving. It does get into gear, but feels like not fully engaged, it does not matter which way to switch up or down or which gear it is.
Its quite random effect. And hard to re produse. One day it works one day not.
Hot or cold does not matter.
I read in service manual that, it could be cam drum, or forks that move gears are out of spec, or bent.

I'm not really keen to get inside of the gearbox unless it really necessary.

It is really hard to find any good mechanic. The workshop i used to go,  is out of the business now, they were really good..

If anyone have recommendations for SE23 area, i would really appreciate it.
Title: Re: Engine struggle to start
Post by: Art on 01 November, 2020, 10:27:35 AM
*Originally Posted by alexg [+]

If anyone have recommendations for SE23 area, i would really appreciate it.

Try asking that question on London Bikers (https://londonbikers.com/) they're most a friendly bunch