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Discussion Starter · #1 ·
Purchased a not running 2013 CBR250 for a project. Fuel pump and solenoid were both bad and have been replaced successfully. The issue at hand now is a slow cranking until it drains the battery to death. Yes, the lights dim and the voltage dips down to 6-7volts when starter cranking. Yes, I've thrown two brand new batteries at it :) The starter is receiving the same voltage (6-7V) during starting attempts, so I'm thinking it's more of an electrical connection issue or a bad starter draining the battery.

My concern lies within the motor, however. I cannot bump start this sucker! 2nd gear, 3 gear, 6th gear... That back tire locks up every time. I'm no stranger to bump starts, so I'm surprised. I'm able to spin the motor by hand with my wrench but I'm not sure how much resistance is normal. Is it possible that the motor resistance is high enough that it's draining the battery? I turned the motor by hand a few times and didn't note any binding or rough spots, so to speak.

Considering that the starter terminals are picking up the same voltage from the battery, I still lean towards electrical connection, but not being able to turn the motor during a bump start whatsoever catches my attention.

What say you?
 

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Discussion Starter · #2 ·
Ran a spark and compression check. Spark is good, compression is not (30psi). I have heard that motors with low compression are much harder to start, so that is a potential explanation. There are 30k miles on the odometer so I'm not surprised if it would need a new piston, rings, sleeve, and valve adjustment at a minimum. Can get a used motor for about $800-$1000 but it might be worth the venture to dig into this motor first for the experience.
 

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Battery voltage should be +10v cranking. ECU won't work if voltage is any lower than this.

Where are you measuring this 6-7v?

1. Quick test. Jump-start bike from known-good auto battery (that starts car easily). Connect jumper-cables with car off and leave off. Then try starting bike again.
 

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Yes, I've thrown two brand new batteries at it :)
As an amateur motorcycle mechanic I participate and understand, well done for the perseverance.
People mistakenly think that doing it yourself saves money in maintenance, it's not true, it's a hobby, and a hobby costs money, and learning costs money.
I'm thinking it's more of an electrical connection issue or a bad starter draining the battery.
Maybe, but you also wrote this ...
I cannot bump start this sucker! 2nd gear, 3 gear, 6th gear... That back tire locks up every time.
...I'm able to spin the motor by hand with my wrench but I'm not sure how much resistance is normal.
...compression is not (30psi). I have heard that motors with low compression are much harder to start, so that is a potential explanation
YES
Can get a used motor for about $800-$1000 but it might be worth the venture to dig into this motor first for the experience.
How much time you want and are willing to invest in it, it's your choice, such a project can last for months, you will learn a lot from it, and will also derive a lot of pleasure, provided you have the time, patience, and money to invest even if you need to buy suitable tools. Keep updating what's going on with you, it's really interesting.
 

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Ran a spark and compression check. Spark is good, compression is not (30psi).
According to the manufacturer's instructions the compression test is in running engine at 490 rpm(I understand you get to 490 by rotating the motor with the electric starter.). According to the motorcycle book the compression at 490rpm should be 188psi. You did a Static test with engine that does not turn at all (because your electric starter is currently not working). I can not say that 30psi compression of an engine that not turning is good or bad??? How can pressure be built up, with the engine not spinning?
 

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Discussion Starter · #6 ·
Battery voltage should be +10v cranking. ECU won't work if voltage is any lower than this.

Where are you measuring this 6-7v?

1. Quick test. Jump-start bike from known-good auto battery (that starts car easily). Connect jumper-cables with car off and leave off. Then try starting bike again.
Actually, I did this on the first new battery I purchased because of the behavior with no change - that's why I replaced it thinking it could have been a battery sitting on the shelf at Walmart for a couple of years. I tried charging the original battery with my automotive charger at 2 amps but it fried the battery and blew the main fuse, so I sat that aside and purchased an 800mA battery tender. I'm measuring that voltage across the battery terminals and also at the terminals of the starter motor. I let it charge overnight and although there was a slight improvement, it's only cranking at ~60rpms for a couple of seconds and significantly slows.
 

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Discussion Starter · #7 ·
According to the manufacturer's instructions the compression test is in running engine at 490 rpm(I understand you get to 490 by rotating the motor with the electric starter.). According to the motorcycle book the compression at 490rpm should be 188psi. You did a Static test with engine that does not turn at all (because your electric starter is currently not working). I can not say that 30psi compression of an engine that not turning is good or bad??? How can pressure be built up, with the engine not spinning?
To clarify - it does crank and spin with the electric starter. Bump starting doesn't get the motor moving though.

I certainly didn't know about the compression read at a specified rpm. Like I told Danno, I'm looking at ~60rpms right now with how sluggish it is. After having the battery sit on a charger all night, it had a bit more energy and the psi reading doubled to 60psi and decreases with the fall of rpms.

But... Shouldn't the starter be pulling more than 6-7V?
 

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, I'm looking at ~60rpms right now...the psi reading doubled to 60psi and decreases with the fall of rpms.
So I got it right, the compression test you do has no scientific value that can be deduced from it about the state of the compression.

Shouldn't the starter be pulling more than 6-7V?
YES. Provided the starter has where to pull the necessary voltage. And in your case it does not, the battery collapses under the load of the starting process (starter + computerECU + lighting + fuel pump).
I've thrown two brand new batteries at it
The purpose of any experiment/Test is to learn from it, if you destroyed two new batteries like that, why do you continue this test. Go ahead, the problem is not with the battery, and yesterday you've destroyed another one?
My concern lies within the motor, however. I cannot bump start this sucker! 2nd gear, 3 gear, 6th gear... That back tire locks up every time.
Maybe even this test it went wrong. Because if the surface is slippery, no matter why, then it is clear that it is not possible to conclude that the engine is stuck. Now it is also clear that a proper surface also would not cause the engine to start, because you lack voltage, it is impossible to do and succeed bump start with a dead battery(6-7V).

Sorry, I do not know you, in my opinion before you continue work, you need to buy suitable technical literature, Honda's book is excellent, Haynes' book includes a study chapter of the basics of mechanics. You need to read and learn because you seem to lack a basic background. Spend time studying, in the long run it will really pay off for you. Alternatively, I'm not good enough to help you.
 

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Actually, I did this on the first new battery I purchased because of the behavior with no change - that's why I replaced it thinking it could have been a battery sitting on the shelf at Walmart for a couple of years. I tried charging the original battery with my automotive charger at 2 amps but it fried the battery and blew the main fuse, so I sat that aside and purchased an 800mA battery tender. I'm measuring that voltage across the battery terminals and also at the terminals of the starter motor. I let it charge overnight and although there was a slight improvement, it's only cranking at ~60rpms for a couple of seconds and significantly slows.
did you jump-start bike with a car? that's the test you want to do

1. drive car up next to bike, turn off car
2. connect jumper cables between car battery and motorcycle battery
3. start bike

Did starter spin better and start bike?
 

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Discussion Starter · #10 ·
So I got it right, the compression test you do has no scientific value that can be deduced from it about the state of the compression.


YES. Provided the starter has where to pull the necessary voltage. And in your case it does not, the battery collapses under the load of the starting process (starter + computerECU + lighting + fuel pump).

The purpose of any experiment/Test is to learn from it, if you destroyed two new batteries like that, why do you continue this test. Go ahead, the problem is not with the battery, and yesterday you've destroyed another one?

Maybe even this test it went wrong. Because if the surface is slippery, no matter why, then it is clear that it is not possible to conclude that the engine is stuck. Now it is also clear that a proper surface also would not cause the engine to start, because you lack voltage, it is impossible to do and succeed bump start with a dead battery(6-7V).

Sorry, I do not know you, in my opinion before you continue work, you need to buy suitable technical literature, Honda's book is excellent, Haynes' book includes a study chapter of the basics of mechanics. You need to read and learn because you seem to lack a basic background. Spend time studying, in the long run it will really pay off for you. Alternatively, I'm not good enough to help you.
I didn't destroy two batteries, I tested it with two new batteries to rule the power source out. I did, however, destroy the older battery that came with it on the 2A charger :) I've previously purchased and referenced the Honda service manual. My question is not addressed by the service manual and requires more investigation. The motor is not seized and turns with the starter motor. The battery is not dead and sits at 12.6V. It won't bump start simply because I cannot get the wheel to turn the motor when dumping the clutch.

I'm here to bounce ideas around about it being mechanical vs. electrical. For instance, there was another member who had a similar problem (slow cranking) where the jury was out banging their fists that it was a dead battery. It turned out to be a bad carb diaphragm for him (that's what he said at least lol). Granted, I don't have a carb on my 2013, but it helps me keep an open mind when approaching these issues.
 

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Discussion Starter · #11 ·
did you jump-start bike with a car? that's the test you want to do

1. drive car up next to bike, turn off car
2. connect jumper cables between car battery and motorcycle battery
3. start bike

Did starter spin better and start bike?
Unfortunately not - I tried a second time and it blew my main fuse and potentially damaged by battery making it hot to the touch so it will be my last try 😂
 

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30 psi compression is way too low and 60 psi is way too low as well. Not surprised at all that the engine doesn't start with such a low compression.

Not too sure whether the issue is the head gasket, rings, or valves. Do you know the history of the bike? When you visually inspect the engine, is there any damage to it?

Are you a pretty handy mechanic? Working on a motorcycle engine is fairly easy and not too costly on a CBR250R.
 

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I'm here to bounce ideas around about it being mechanical vs. electrical.
Brainstorming, philosophy, everything is fine, so maybe I did help you.
If so, give me likes, and the more likes is better, it's the minimum wage for my volunteer effort.
But sorry, I can not help you. No Help No Likes(Just a waste of time-Sorry).
 

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Discussion Starter · #14 ·
Brainstorming, philosophy, everything is fine, so maybe I did help you.
If so, give me likes, and the more likes is better, it's the minimum wage for my volunteer effort.
But sorry, I can not help you. no help no likes(Just a waste of time-sorry).
That’s the oddest thing I’ve heard someone ask for on a forum.

30 psi compression is way too low and 60 psi is way too low as well. Not surprised at all that the engine doesn't start with such a low compression.

Not too sure whether the issue is the head gasket, rings, or valves. Do you know the history of the bike? When you visually inspect the engine, is there any damage to it?

Are you a pretty handy mechanic? Working on a motorcycle engine is fairly easy and not too costly on a CBR250R.
It was definitely a beginner’s bike, but the outward appearance is good - nothing deeper than minor cosmetic damage to the covers. I was really curious if the resistance of a motor could cause slow cranking with battery fatigue, but because I’m still reading a low voltage at the starter I’m going to finish the electrical troubleshooting first. As Tamir said,Compression readings are done at a certain rpm and this bike isn’t close to meeting that. In my ignorance, I assumed compression was the same no matter the rpm, so those readings are not diagnostic.

Going to have to do more investigating - might pull the starter itself to test It. Start with the smaller things first :) the voltage drop is really bugging me. Will keep post any updates.
 

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Discussion Starter · #15 ·
Bench tested the electric starter motor - runs well and is running on ~11.5V. Going to clean the connections well at the starter upon install and see if that has any effect.

From what I’ve read and watched, the motor should start up immediately when connected to the power source. Mine takes 1-2 seconds before it begins spinning. Normal for anyone else?
 

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Unfortunately not - I tried a second time and it blew my main fuse and potentially damaged by battery making it hot to the touch so it will be my last try 😂
I tried charging the original battery with my automotive charger at 2 amps but it fried the battery and blew the main fuse, so I sat that aside and purchased an 800mA battery tender.
you need to be more accurate in your reporting. You said main fuse was blown by charger. Do you know WHY it blew main fuse?

So have you or have you not tried to jump-start it with jumper-cables from known-good car battery?
 

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Discussion Starter · #18 ·
Update:

My issues were not electrical, although there were indeed electrical side effects that would appear as a bad battery, solenoid, etc… I removed the engine today and began a top-end tear down. I’ll let’s these few pictures mostly speak for themselves. The piston arm is completely seized - you can see some of the bearing that disintegrated in the first picture (best picture I could get now). Will have to crack the case open so really get a good idea. Will purchase a used motor on eBay and this will be for parts :)

Hood Automotive tire Automotive lighting Automotive mirror Automotive side-view mirror
Product Wood Sleeve Material property Magenta

Idiophone Musical instrument Bell Gas Automotive wheel system

Automotive tire Audio equipment Serveware Gas Automotive wheel system
 

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Hmmm...well, that's not good news...

The part that threw me was it seemed to spin over manually without extreme effort.

Probably another victim of the "backwards oil filter" installation.
 
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