Author Topic: Running out of puff  (Read 4010 times)

Offline alanp

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Re: Running out of puff
« Reply #30 on: 09.07. 2010 16:01 »
Bill, you're quite right, it is mathS, as a short version of mathematicS. 
Regards
Alan
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Offline MG

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Re: Running out of puff
« Reply #31 on: 09.07. 2010 21:20 »
Bill, your maths are absolutely correct, but I don't think it will make such a huge difference in top gear performance.
According to my self-made gear-ratio - speed - rpm Excel spreadsheet, the standard gearing (21T-43T-19T-42T) would result in 4050 rpm @ 60mph in 4th gear (4900 in 3rd). Hubies 22T engine sprocket will result in 3860 at the same speed (4680 in 3rd). You might have to stay in third a bit longer, but still it should be pulling well enough in 4th I would think.

All values assuming a STD clutch basket and g'box sprocket is fitted.
1955 A7 Shooting Star
1956 A10 Golden Flash
1961 Matchless G12 CSR

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Offline Hubie

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Re: Running out of puff
« Reply #32 on: 10.07. 2010 01:47 »
I am running completely standard gearing on the bike now but still have nothing left in top gear.  I am leaning towards cam timing but am still unsure.  I made new rocker box covers last night and now there's no compression and the bike will not start.  I will have to re do the valve clearances it would seem and then go from there.  I made doubly sure that the pushrods are all in position and re checked again this morning.

The saga continues.  I would just like the bike to have the go it is supposed to have.

Cheers,

Dave.
1959 BSA Golden Flash
1956 Royal Enfield Super Meteor
1955 Royal Enfield 350 Bullet
2007 Harley Davidson Sportster 1200 Custom

The early bird gets the worm, but the second mouse get's the cheese!

Online trevinoz

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Re: Running out of puff
« Reply #33 on: 10.07. 2010 03:44 »
Dave,
            Have you ever thought why the previous owner got rid of the Flash?
Check your compression and have a look at the timing marks, as Musky suggested.
Another little thing to check is that the correct idler pinion is fitted.
Count the teeth between the dot and the dash.
It is not unknown for an early long stroke pinion to be fitted.
Trev.

Offline Hubie

  • Dave Huybens
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Re: Running out of puff
« Reply #34 on: 10.07. 2010 08:19 »
Thanks again Trev,

I will check that in due course, though I have just reset the valve clearances and the bike is running again.  Not only that but it feels as though there is a stack more power available.  In the past when the bike was revved on the centre the vibration higher up in the rev range would cause the bike to drag backwards along the ground.  Now a blip of the throttle and she rockets backwards.  Perhaps the beast has been awoken.  It has just started to rain here so a test ride when weather and time permits is going to be very interesting.

Thanks to all for their continued advice and support.

Dave
1959 BSA Golden Flash
1956 Royal Enfield Super Meteor
1955 Royal Enfield 350 Bullet
2007 Harley Davidson Sportster 1200 Custom

The early bird gets the worm, but the second mouse get's the cheese!

Online bsa-bill

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Re: Running out of puff
« Reply #35 on: 10.07. 2010 10:12 »
yep mine does that, I use the throttle to move it about the garage.
Well good luck with it when you get it out on the road, it's rained hear in Northumberland through the night, supposed to get sunny this afternoon though
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco