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My CB500 performance upgrades

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fryatuck
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Location : King's Lynn, Norfolk.

Re: My CB500 performance upgrades

Post by fryatuck on Mon 28 Jan 2013, 7:14 pm

so your saying that these kits are not much good ??
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alexibrow
Four's a...something...
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Mon 28 Jan 2013, 10:07 pm

fryatuck wrote:so your saying that these kits are not much good ??

I'm saying that the one that was supplied to me was next to useless. It's basically a very expensive way of lifting the needles by one shim each, and going up one size on the mains.

I contacted them several times to let them know of the issues, and they haven't replied to me.

I'll leave it to you to decide.

Personally, I'd go see a dyno guy and buy the parts you need from Allen's Performance (part numbers and links above).
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alexibrow
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Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Mon 28 Jan 2013, 10:09 pm

*Sigh* I'm going to have to do a dyno run aren't I! Very Happy
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fryatuck
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Posts : 140
Location : King's Lynn, Norfolk.

Re: My CB500 performance upgrades

Post by fryatuck on Mon 28 Jan 2013, 10:11 pm

was looking on ebay can get 125 jet for less than £5 each so maybe that would be the way as I'm skint.
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alexibrow
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Mon 28 Jan 2013, 10:22 pm

From memory, I think the pair of main jets came to about £8 from Allens. You'll need a pair of needle shims too.
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fryatuck
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Posts : 140
Location : King's Lynn, Norfolk.

Re: My CB500 performance upgrades

Post by fryatuck on Mon 28 Jan 2013, 10:27 pm

I will have to look into it me thinks Very Happy
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lc500
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Posts : 2

Re: My CB500 performance upgrades

Post by lc500 on Wed 03 Apr 2013, 11:32 pm

what's the deal with this dyno run Alex - you done it yet or what?? any power difference?

I've just fitted a scorpion can to mine, removed baffle, and getting that popping on the overrun. Is that bad for the engine in the long term??? (I thought it sounded cool) . I'm changing plugs this week so I'll see how they're looking and have a better idea i guess.

But yer would be good to hear how your tuning finished
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alexibrow
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Thu 04 Apr 2013, 8:32 pm

lc500 wrote:what's the deal with this dyno run Alex - you done it yet or what?? any power difference?

I've just fitted a scorpion can to mine, removed baffle, and getting that popping on the overrun. Is that bad for the engine in the long term??? (I thought it sounded cool) . I'm changing plugs this week so I'll see how they're looking and have a better idea i guess.

But yer would be good to hear how your tuning finished

If all you've done is fit a de-restricted silencer, your engine is running lean. It's anyone's guess as to what damage this will cause; it will probably be fine, but worst case scenario is melted valves and pistons... affraid

I might get a dyno run done, but money is tight due to my Triumph's ongoing reliability problems...
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Hario
Two Tone
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Posts : 124
Location : London

Re: My CB500 performance upgrades

Post by Hario on Thu 04 Apr 2013, 9:54 pm

Personally i think popping is really nothing to worry about. Unless you have backfires when you close the throttle, although you are lean enough to pop it is not going to do any harm.


Engines pop when you close the throttle as a lean condition is created when you go from running at high revs on the large main jet, to fully closed throttle putting you back on the more restricted pilot jet circuit which feeds far less fuel to the engine - not enough to cope with the revolutions of the engine created when you engine brake. Many bikes pop from the factory for this reason, the CB carb is a bit more sophisticated and can have it tuned out, but its not really important unless its excessive.


If it bothers you, there will be a pilot air screw which adjusts the fuel air mix when the throttle is closed, taking that screw 1/4 of a turn out will put a bit more fuel into the idle circuit. There will be a screw on each carb body and they should be adjusted equally (im not talking about the idle adjuster knob btw)


Re-jetting is not likely to be very beneficial unless you increase the flow of both the exhaust and the airbox/filter significantly. Setting the bike up richer will make it run cooler, it will also probably hurt fuel economy and a healthy CB rarely even starts its radiator fan, so why bother?
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alexibrow
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Thu 04 Apr 2013, 10:48 pm

Re-jetting is not likely to be very beneficial unless you increase the flow of both the exhaust and the airbox/filter significantly. Setting the bike up richer will make it run cooler, it will also probably hurt fuel economy and a healthy CB rarely even starts its radiator fan, so why bother?

For several reasons:

Making any changes to the intake or exhaust in terms of reducing the restrictions inherent in the stock set-up, will help the engine to flow more air. The more changes you make, the more air the engine can flow. As said: mine has a de-restricted exhaust and a K&N panel filter fitted, which in my view is significant. You can of course fit a pod filters or individual cone filters for maximum air flow, but doing away with the air box introduces other problems that (for an every day commuter at least) may be undesirable.

In order to compensate for the increased air flow, you need to increase the amount of fuel so that the air:fuel ratio (AFR) is optimised; it's NOT about setting it up to run richer as you suggest. It's about optimising the AFR so that performance, drivability, fuel economy and reliability are optimised, just as they are by Mr Honda at the factory (let's ignore emissions regulations for now).

For the record: my bike runs much better with the fuelling set up to suit the exhaust and air filter; fuel economy is still excellent, in fact I haven't noticed a difference:

Link to my Fuelly CB500 page

If you fit a road legal can and leave the baffle in, on its own, it's OK not to re-jet; similarly, if you fit a K&N panel filter and nothing else, you can get away without rejetting. Your AFR will not be optimised in either case, but it will be so close to stock as to be hardly noticeable to most people, in most conditions (although plenty of people report a flat spot in the 3000-4000rpm range after fitting a K&N filter).

As soon as you start combining modifications, or even just remove the baffle from your Scorpion can (or whichever make you happen to have), you WILL notice the difference: there'll be a big dip in the power curve right where you spend most of your time when riding about. In my opinion (based on many years research and playing about with all kinds of normally aspirated carburated engines), it's absolutely essential to re-jet for these mods.

If you're foolhardy enough to fit individual cone filters and a straight-through exhaust, without re-jetting, expect to melt some spark plugs and / or engine internals.

I've been riding my CB500 nearly every day since performing these mods, and I'm really very happy with it. In fact, I can't recommend doing this to your own bikes enough. As long as you don't mind the noise from the exhaust!
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lc500
Newbie
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Re: My CB500 performance upgrades

Post by lc500 on Mon 08 Apr 2013, 1:02 pm

cheers folks. I can tell there's a very knowledgeable crowd on here.

Changed the plugs the other day, pretty normal wear tbh. They'd been running with the de-restricted exhaust since before christmas so fairly happy with that.
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Fishy
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Re: My CB500 performance upgrades

Post by Fishy on Sun 16 Jun 2013, 11:51 am

All excellent info. However I would add SBS is where my bike were serviced and dyno'd. I paid for the dyno only to get Podge rev the nuts of the bike which is what I guess he has to do. However 3 months of chasing produced nothing but excuses. 'Dyno print man on hoilday', 'PDF print issues', so never found out what my bike was doing. I needed this to gauge next steps with Carbs as I had fitted a K&N filter as mentioned in other post on this forum and it was this orginal post I have just found again that pointed me to SBS. Podge said K&N he never recommends so I stuck the Honda filter back in. Still very disappointed with SBS. They should have in my eyes offered a free dyno test if they had lost the original. Instead I got excuse after excuse until I gave up very annoyed saying 'I wondered you had even serviced the bike'. No reply to that question so guess they maybe did not. It cost a lot as it was the valve check etc service.

Very tempted to put the K&N back.
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alexibrow
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Sun 21 Jul 2013, 4:39 pm

Sorry to hear of your tale of woe Fishy. Podge has a very good reputation locally, but I must confess after spending almost £300 he couldn't fix my Triumph's poor running issues (he cleaned and rebuilt the carbs, and did a couple of other things). It was a lot better than before, but still only about 80% right.

I want to get another dyno run done; the rear tyre is nearing the end of its useful life, so I'll get the dyno run done just before I replace it, as recommended by the tyre manufacturers (dyno runs can kill tyres).

Hope to post back with results in a few weeks.
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Fishy
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Re: My CB500 performance upgrades

Post by Fishy on Sun 21 Jul 2013, 6:12 pm

Guess carbs are fiddly things. Just seen a mate today with a VFR not used for a year. Petrol pouring everywhere. Nice bike but he just wants rid of it as needs space etc. I am dropping down some carb cleaning bits and a remote tank so we can try and spot the leak. Got the tank off etc. I think a sticking float on one of the rear cylinder carbs is the issue. Took one of the carbs tops off and needle was coated in varnish. Not massively but enough I think to indicate a likely carb issue over a split tube.

As for my CB500, I put the K&N back in and whilst I still think an idle jet might be partially blocked(also suggested by Podge or his mechanics) the bike seems to run fine with just a little surging around 3,500 RPM. About to service as now done another 4,000 since the last service. I aim to be bold and take the carbs apart once the bike is not my main means of getting to work. So winter time. A little way off so will post then the results.
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alexibrow
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Sun 21 Jul 2013, 6:18 pm

I have a working set of carbs you can have for cheap if you're interested. You could rebuild one set while using the other, keep you on the road. PM me if you're interested.
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alexibrow
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Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Sun 18 Aug 2013, 10:51 am

I've just serviced the CB500, and booked it in to have a new rear tyre fitted at SBS in Lancing.

While it's there, I'm putting it on the dyno for a power run Very Happy

Then it's up for sale.
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alexibrow
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Sun 18 Aug 2013, 12:19 pm

OK, so to recap:

The standard fuelling set-up for the CB500 is as follows:

- Pilot screw set 2.5 turns out
- 38 pilot jet
- 122 main jet
- One needle shim.

My bike engine is standard, except for the following modifications:

- K&N panel filter
- Pipewerx Hawk SL silencer, with baffle removed.

the fuelling on my bike is set up as follows:

- Pilot screw set 3 turns out
- 38 pilot jet (standard)
- 125 main jet (one size up)
- Two needle shims (ie one additional shim).

Dyno run to follow week after next Cool


Last edited by alexibrow on Fri 06 Sep 2013, 3:26 pm; edited 1 time in total
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alexibrow
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Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Wed 28 Aug 2013, 6:53 pm

Dyno run postponed to Friday September 6th.
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alexibrow
Four's a...something...
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Fri 06 Sep 2013, 4:10 pm

Dyno run complete!



It's still rich on the main jet as you can see from the bottom graph; Podge advised that it could go back to the standard one, although it's OK as it is. It's likely that that the emulsion tubes / needle jets are worn at 48,000 miles, which would cause a rich condition (this rich condition is causing the popping on overrun: unburnt fuel is igniting in the exhaust when the throttle is closed).

However, it's a big improvement from before. Throttle response is virtually instant, it pulls really strongly all the way through the rev range, and feels smooth too, for a twin.

Max power is 44.7 bhp (45.3 Ps) @ 9433 rpm.
Max torque is 29.12 ft/lb (39.48 Nm) @ 7349 rpm.

These are rear wheel figures, but they're probably very close to factory.

There you go. Saved for posterity.
As far as I know, no-one else has posted this information on the intertubes, so I hope this is of some use to anyone else wishing to perform some basic mods to their CB500.

It's a shame I have to sell it really, as I was seriously considering getting some head work done next...

Hey ho!
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alexibrow
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Fri 06 Sep 2013, 4:17 pm

BTW, 44.77 bhp at the wheel equates to roughly 68 bhp at the crank, so I'm told. Stock then!
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texzy
Squiddy
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Re: My CB500 performance upgrades

Post by texzy on Wed 18 Sep 2013, 7:21 am

Many thanks for those interesting Curves:D Very Happy
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stormbringer
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Re: My CB500 performance upgrades

Post by stormbringer on Wed 18 Sep 2013, 10:17 am

For comparison, here is the curve I got made shortly after i bought my CB5. Completely standard apart from fitting a K&N-filter.

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stormbringer
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Re: My CB500 performance upgrades

Post by stormbringer on Wed 18 Sep 2013, 10:27 am

alexibrow wrote:BTW, 44.77 bhp at the wheel equates to roughly 68 bhp at the crank, so I'm told. Stock then!
Hmmm...

According to Haynes, the stock engine produces 57 bhp @ 9k5, with torque 47 Nm @ 8k.

My own dyno tells me there are nearly 50 ponies at the rear tire, indicating transmission loss around 7 bhp.

Allow me to question your 68 - 45 = 23 bhp loss figure.
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alexibrow
Four's a...something...
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Posts : 162
Location : West Sussex

Re: My CB500 performance upgrades

Post by alexibrow on Wed 18 Sep 2013, 8:19 pm

Slip of the finger. I meant 58 bhp, not 68 bhp (was told to add approximately 13 bhp to the rwhp figure).
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texzy
Squiddy
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Re: My CB500 performance upgrades

Post by texzy on Thu 19 Sep 2013, 6:27 am

thanks Storm very nice AFR but a very little "richer" (of gas) and better with the Kn ? Strange (or effect of température?) :a good référence. ....
 Alex : so ;yours carbs seem to be a little tired ? (need: needles change and/or deep cleaning ?) but
max Hp seem "rights"
for info the latest CB500 solded in Brazil (near sea level )where (stock) 125 main jets and 40 pilot jets with same stock ait filter; needles (and exhaust):
1/Gicleur ralenti (pilot jet) 40  ref 99103-MAL-0400 :
cb500 98/2004 Brazil
cbr 1000 f 1989 Italy
Xr 250 r 1995 australie + ? cf cmsnl.com
GICLEUR DE RALENTI, #40 27 CBR600FS 1995  CBR 600  BRAZIL 
GICLEUR DE RALENTI, #40 27 CBR600FT 1996  CBR 600  BRAZIL 
GICLEUR DE RALENTI, #40 36 CBR900RRW 1998  CBR 900 FIREBLADE  BRAZIL 
GICLEUR DE RALENTI, #40 36 CBR900RRW 1998  CBR 900 FIREBLADE  BRAZIL 
GICLEUR DE RALENTI, #40 36 CBR900RRX 1999  CBR 900 FIREBLADE  BRAZIL 
GICLEUR DE RALENTI, #40 36 CBR900RRX 1999  CBR 900 FIREBLADE  BRAZIL
2/ puits d'aiguille (holder needle jet )CB500 Brazil 98/2004 : ref 16165-MY5-B60
3/ aiguille (needle ) CB500 Brazil 98/2004 :            ref 16012-MY5-A20
NEEDLE SET, JET 3 CB500V 1997  CB 500  AUSTRIA 
NEEDLE SET, JET 3 CB500V 1997  CB 500 34HP  AUSTRIA 
4/ Gicleur principal  (main jet) 125 ref 99101-443-1250 :
CB500 Brazil 98/2004 +
JET, MAIN, #125 35 CBR900RRW 1998  CBR 900 FIREBLADE  BRAZIL 
JET, MAIN, #125 35 CBR900RRW 1998  CBR 900 FIREBLADE  BRAZIL 
JET, MAIN, #125 35 CBR900RRX 1999  CBR 900 FIREBLADE  BRAZIL 
JET, MAIN, #125 35 CBR900RRX 1999  CBR 900 FIREBLADE  BRAZIL 
JET, MAIN, #125 49 CBR1000FP 1993  CBR 1000 DUAL CBS  BRAZIL 
JET, MAIN, #125 49 CBR1000FR 1994  CBR 1000 DUAL CBS  BRAZIL 
JET, MAIN, #125 49 CBR1000FS 1995  CBR 1000 DUAL CBS  BRAZIL 
JET, MAIN, #125 49 CBR1000FT 1996  CBR 1000 DUAL CBS  BRAZIL

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