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Author Topic: Yoshimura Cam help  (Read 1190 times)

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Offline mj1176

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Re: Yoshimura Cam help
« Reply #25 on: September 05, 2017, 10:22:20 am »
I'll pay the same as 754 and I DO have a bike it can go in :P

hell, I'd send you the 650 cam out of my 550 too if it makes it easier for you to complete your project :)

Offline BomberMann650

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Re: Yoshimura Cam help
« Reply #26 on: September 05, 2017, 01:30:45 pm »
40 year old stuff .....get used to it

This.

If ya really can't accept a little pit on the cam.  Send it my way, I'll put it out to pasture.
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Offline parm94

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Re: Yoshimura Cam help
« Reply #27 on: September 14, 2017, 10:41:03 am »
My 550 could use that if you've still got it.

Offline 550Resto

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Re: Yoshimura Cam help
« Reply #28 on: September 20, 2017, 03:39:43 pm »
Parm sent you a PM

Offline HondaMan

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Re: Yoshimura Cam help
« Reply #29 on: September 20, 2017, 07:40:29 pm »
If it was on my around-town bike...

...if it is a lobe, it may eventually cause rocker foot wear on that one rocker, but nothing serious. I have seen high-mileage engines with cams like that, and the only place that wore was right around those pits: it lost a little cam lift.

...if it is on the bearing, I wouldn't flinch to re-use it, but not with light oils.

...unless it is for someone else's bike...then it's not good enough, IMHO...  ;)
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Offline parm94

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Re: Yoshimura Cam help
« Reply #30 on: November 08, 2018, 05:34:20 pm »
Specs for the cam are:

1.00 base circle (stock is 1.110)

Exhaust .310
Intake .325

A local shop advised a grind on all the lobes. The base circle is already at 1.00, would this be a good idea?

Offline bryanj

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Re: Yoshimura Cam help
« Reply #31 on: November 09, 2018, 01:23:18 am »
No, i have worked on these for many years and that will run ok for a long time. Yoshi cams need a lot more ignition advance depending on grind and also you need a bigger rear sprocket as the power band is pushed higher up the rev range.
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Offline dave500

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Re: Yoshimura Cam help
« Reply #32 on: November 09, 2018, 03:08:58 am »
I wouldn't say Yoshi cams per say bryanj,and as far as a larger rear sprocket all your doing is gearing it all down,torque is what ya want.

Offline bryanj

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Re: Yoshimura Cam help
« Reply #33 on: November 09, 2018, 03:29:59 am »
Yup, i actually put a yoshi cam in a 500 in the 70's and the paperwork told use way more advance plus with standard gearing it could only just pull away from a standing start, hence the bigger sprocket so you had more revs for the speed to get into the higher powerband
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline dave500

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Re: Yoshimura Cam help
« Reply #34 on: November 09, 2018, 03:40:17 am »
so in essence you lost low rpm torque?

Offline dave500

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Re: Yoshimura Cam help
« Reply #35 on: November 09, 2018, 03:56:08 am »
I think Honda got the gearing spot on for the 500/550s?they just lacked a little torque in my opinion?having the little engine try to make more power with more torque just wasn't gonna happen with just an over bore on the 550?but gains can be had with cleaning up head ports and use of electronic ignition.
« Last Edit: November 09, 2018, 01:41:31 pm by dave500 »

Offline bryanj

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Re: Yoshimura Cam help
« Reply #36 on: November 09, 2018, 05:08:01 am »
Yes you lost both torque and power at low revs. Yoshi cams were primarily designed for racing or fast street work where you keep the engine buzzing. Honda did not spend millions on R&D to get a street bike wrong, on the odd occasion they made minor cockups(cx500 cam chain tensione for example) but they mostly got it right
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

 

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