A few puzzling thing...

Hey, what projects are you planning or preparing for? CBX, other motos, workshop, WHATEVAH!
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CBX1000FAN
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A few puzzling thing...

Post by CBX1000FAN »

I have a 1978 CBX converted into a Streetfighter with the front end from a CBR 1000RR and the rear from a Suzuki GXR 1000. The project is now nearly completed and I have taken a few test rides. Each time I ride I feel the rear brake "bind". The rear disc brake becomes very hot - yet when the bike is on the stand the rear wheel turns freely. I have bled the brakes and checked the brake cylinder pistons - all freely moving. Nothing is out of alignment. Where else can I check?

I also notice that once the bike is at running temperature, switched off and restarted, the battery struggles for the first second or so before it starts... It is a new 360 CCA battery - I see 14V while riding on the voltmeter I installed, so I assume the charging system is OK... Can the compression go up when the bike is hot? What else will cause the battery to behave like that?

Any ideas??

Regards!

Larry Zimmer
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Re: A few puzzling thing...

Post by Larry Zimmer »

With the bike on the stand, apply the rear brake hard. Does it release immediately? If not, I would suspect the return hole in the m/c is plugged. One other thought -- are you possibly dragging your toes on the brake pedal while riding? Third option would be a clogged brake line that is open just enough to allow pressure through. BUT, is very slow to bleed back down after release. I really suspect the m/c, though.

About compression -- yes it does increase with temp. Check the voltage across the battery while cranking. It should be 10 ish or higher. If not, it's either some terminal corrosion/loose terminal/ bad wire, etc. A possibility is that it could be a bad battery. Even 'new' batteries can sometimes be defective. Then, too, a 'hot' starter motor. My first thing would be check all connections for corrosion, etc.
Larry Zimmer
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CBX1000FAN
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Re: A few puzzling thing...

Post by CBX1000FAN »

Thanks!! I'll definitely check! Some good points you make!! Regards.

steve murdoch icoa #5322
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Re: A few puzzling thing...

Post by steve murdoch icoa #5322 »

Some other things to check in regards to difficulty in starting a hot engine.
viewtopic.php?t=7941

CBX1000FAN
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Re: A few puzzling thing...

Post by CBX1000FAN »

steve murdoch icoa #5322 wrote:
Sun Aug 08, 2021 8:26 pm
Some other things to check in regards to difficulty in starting a hot engine.
viewtopic.php?t=7941
Thanks! Will check these things too!! Regards!

AshishNJ
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Re: A few puzzling thing...

Post by AshishNJ »

On the hot start issue, I have a 17 Aprilia tuono. It used to be very bad with hot starts. I changed the cables going to starter to thicker gauge. It behaves much better.
1979 CBX (faster Red)
1981 CBX Streetfighter
2017 Aprilia Tuono.
Past rides : FZ1, BMWS100rr,S1000r,k1300S,YAMA RD350,Enfield 350

CBX1000FAN
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Re: A few puzzling thing...

Post by CBX1000FAN »

AshishNJ wrote:
Tue Aug 10, 2021 9:06 am
On the hot start issue, I have a 17 Aprilia tuono. It used to be very bad with hot starts. I changed the cables going to starter to thicker gauge. It behaves much better.
Makes sense! However, the CBX does not do this each and every time. I'll start it (hot) and it may have the hesitation (I see the voltage drop to 10.8V) - it then starts and I let it idle for 15 sec. - switch off and start again and it just starts perfectly... It is if it sometimes stops the motor against a compression stoke (if that is possible?). Regards!

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