RR7 Hard to start when hot

Discussion in 'Maintenance' started by Lock, Sep 12, 2020.

  1. Lock

    Lock Active Member

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    Had problem with RR7 since I bought it last November. Bike has 44k miles and New Yuasa battery. Bike starts great when cold, starter spins up quickly and fires without issue. But after a ride when hot >50oC, when I go to start it again say at a petrol station it doesn't fire easily, starter gets sluggish and bit rough when it does fire but then OK. Sounds like battery is going flat, but checked voltage today and doesn't drop below 10.5v when it's trying to start. So doesn't seem to be battery, can leave it two weeks and starts fine (when cold), but this hot thing is frustrating as sounds like battery is going to go flat. Have done a search on Web but although seems a problem on a number of honda, no clear solution. So could be bad earth (odd only when hot), starter wiring or solenoid, starter motor, fuel evaporation, valve clearances - anything else! Anyone had this experience on blade and solved it (didn't have this issue on my other 2007 blade). Cheers
     
  2. Muffking

    Muffking God Like

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    Could still be the battery as 10.5v when turning over is still quite a drop.
    Is your bike on charge overnight?

    How about you prepare a jump start at home for when you return after a ride and see if it turns over better off a jump start. At least it prove if there's a battery/charging problem or not.
     
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  3. stelwalker

    stelwalker Active Member

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    Had same thing on my 2018 blade earlier this year was the battery in the end
     
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  4. Lock

    Lock Active Member

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    Still having issue, so sounds like battery might be culprit. Was thinking of going lithium (helps calm the manic behaviour - apparently!). Any recommendations for high cca long lasting ones? Also read a few posts that rectifier will also need changing, is that necessary? If so recommendations for best one? Cheers
     
  5. Kentblade

    Kentblade God Like

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    There’s nothing wrong with lead/acid batteries in good nick.

    When the bike is hot, the compression is higher, hence it’s possible that it will crank easier when cold, but the battery struggles to provide enough current when the bike is hot, even new batteries can be faulty.

    As you state it’s a new battery, have you had it tested under load to see if it’s delivering the output it claims?

    Not sure if you suspect the battery why you would be changing the RR unless it’s not delivering the correct voltage at optimum engine revs. So again can only assume you have gone through the electrical system and confirmed if all earths and components are performing to spec.
     
  6. DazK

    DazK Active Member

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    Yuasa battery all the way. It’s not cheap but I’ve never had a problem since replacing it and that’s also what was on when I bought her (most likely the original). Best cca for the money in a lead/acid battery. My friend had a motobatt one and had the same issues as you with his his rr4.
     
  7. Lock

    Lock Active Member

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    Had a new Yuasa battery fitted before i got the bike last year, plus it had stator by the looks, not sure about regulator - so must have had charging issues. Had engine covers fitted and heard they can cause some additional overheating to the stator and cause it to burn out, so removed them. Must admit that the bike had been sitting for some time before i got it, and although i've taken out on long rides and had it sporadically on charge, never really left it trickle charging for period of time. Have got it on now, so will see what its like next week and if the starting is better. Will also double check the charging and power drop on starting
     
  8. Nik Stojkov

    Nik Stojkov New Member

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    Any luck with this? Mine seems to be struggling with similar issues (fine starting when cold, not so great when hot, or after the time it takes to fill the tank) and am going to start digging with a multimeter this afternoon.

    I have a sneaking suspicion it's just a buggered battery, but also not sure if the fan is drawing too many amps...etc
     
  9. Lock

    Lock Active Member

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    Same symptoms as mine, starts fine, can travel 3 miles and then it's a pig sounding if battery is going flat. Can ride it back, leave it half an hour and starts on the button! Got bike on permenant trickle charge now but not ridden for a while. Have valve check to do before spring, have been told that could be an issue when hot if out of tolerance when. If they are OK (or fixed) and still have have problem after trickle charge then likely battery - will probably go lithium if that's the case!
     
  10. Nik Stojkov

    Nik Stojkov New Member

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    I spent the afternoon poking multimeters in various places, and the only conclusion I came to, is that the Radiator fans suck a hell of a lot of juice. (I should point out I have an 08, but the problem seems to span a fair few models). This is assuming that the starter, RR, plugs, coils, fuel pump...etc are all fine.

    When they kick in, the voltage drops a fair way, even when the bike is on. So I think it just takes a bit of time for the battery to recover, especially if they're still on when theres no electricity being generated.

    I checked my charging system using this manual that I found in the depths of either here of another CBR forum, and everything checks out

    https://cdn.shopify.com/s/files/1/1091/5694/files/fault-finding-diagram.pdf?235929069374954073

    Was the "pre ignition" sequence on your all ok? Fuel pump primes, various noises ...etc?
     
  11. Fatboy

    Fatboy Active Member

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    Just a few things I've saved over the years for "bike wont start"
    Bike wont start when warm-:

    ECT, faulty

    Valve clearance need doing

    Vacuum in Fuel Tank

    Reg/Rec getting Hot

    Power Commander- Unhook then remap when warm

    Starter Motor

    Battery

    Ignition Pulse Generator

    Cam Sensor

    But battery is top of the list for this fault
     
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  12. dern

    dern Well-Known Member

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    #12 dern, Jan 6, 2021
    Last edited: Jan 6, 2021
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  13. Nik Stojkov

    Nik Stojkov New Member

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    'Effing brilliant, like being back at uni! Nice one
     
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  14. Broadie

    Broadie Active Member

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    What's your charging voltage when running?
     
  15. Lock

    Lock Active Member

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    So think problem is sorted now, and this is what I found along the way.

    Did valve clearances - made no difference.

    Changed to lithium battery - better but still not great

    Reg/Rec and Stator knackered, not charging properly - certainly didn't help!

    Put on second hand starter - no difference

    Cleaned all grounds and pos/neg terminals from battery to starter - no difference.
    Whilst doing that though noticed batt negative earth lead had blueish corrosion at both ends of copper cable and wire looked quite brittle. Fitted new cable (£26 from Fowlers) and starting is significantly better, dare I say normal! Doesn't sound sluggish when hot any more so seems like that was likely culprit. Bent the old cable and some of the wires broke, so think that although it looked OK, the cable wasn't earthing as it should. Done about 400 miles on it since with a number of hot starts and all seems good - fingers crossed!
     
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