Dyno costs and am I being fobbed off?

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Me and my brother put the restrictors in my CB500 the other day (they were included by the guy in the sale). So today I took it to Double Take Motorcycles in Southampton for a dyno test to check it was under 33bhp. Cost me £45 inc. VAT, is that an average-ish price for a dyno run?

My other worry is that the bike came out at 22bhp. The guy said he can file out the holes and dyno it again, and keep fiddling around with them until it gets to 33bhp ish for another £55, making £100 altogether. My question is, how likely is it that he did a dodgy run to get me to pay more to fix a problem that isn't there?

From what it looks like the top speed is ~87mph.

Bit of a noob on this topic but couldn't find any other dyno places near my area either so hard to get another opinion.

Any help greatly appreciated as currently I have it booked in for next Friday.

Cheers guys!

lllN30lll · World Chat Champion Joined: 12 Jun 2005 Karma :

most I've paid is £20.

Least I paid was a tenner.

and I paid £25 for an ECU remap, which is a steal.
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CRF450R

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Possibly is a bit much for a straight power run. Depends if they were doing anything else at the same time (balancing carbs?).

When you fitted the restrictors were the holes in the washers in the centre or offset to one side? If offset to one side, how did you mount them on the bike?

A speed reading on a dyno is pretty meaningless. It is just a factor of the gearing. Gear up a 50 high enough and it would indicate a silly speed on a dyno if you had enough time.

All the best

Keith
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carlperkins00... · Crazy Courier Joined: 16 Jun 2009 Karma :

yeah if the holes in the inlet blades (restrictor washers) was offset...
you need to insert the blades so that the hole is nearest to the bottom of the carbs.

if you put them in upside down it could mean less power.
i'd double check before you shell out £55 to have them altered.

if they were a cb500 kit that was bought then the holes should be the right size, you shouldnt file them out. in that case..
he is either ripping you off or theres something else wrong with the bike.

check the inlet blades first, then if they are correct find another dyno place.

hope this helps. Carl.

Handsome · World Chat Champion Joined: 30 Dec 2005 Karma :

I've just payed 30 of the Queens English whole round Pounds for a Dyno Session...
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Previous Bikes...Honda NSR 125 RR...Kawasaki Zephyr 550...Suzuki SV 1000 S...Yamaha FZ8...Current Bike...Suzuki GSX-R 750...

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

That's probably it then, I put them in with the holes in the washers towards the top of the inlet rubbers. Would that make 10bhp of difference?

The guy did nothing else to the bike, so I guess I got ripped off. Spose there's nothing I can do about that now, live and learn.

I'll get the washers out and put them in properly, then maybe clean the chain, get new plugs and air filter and see if I can get the carbs balanced (it's a 15 year old bike and don't know when that was last done). My dad reckons those things might gain a few bhp.

After that I guess I'll look for another dyno place. I spent 2 hours looking and only found this one, anyone suggest any near Southampton?

I don't know where the kit came from, it was just thrown in with the bike, although the owner didn't seem like the kind of guy to buy some random washers and hope they worked!

Any other things I should be doing from here?

Thanks alot Smile

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Probably make quite a bit of difference having the washers in upside down. And if not serviced for a bit then a good service will help.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

carlperkins00... · Crazy Courier Joined: 16 Jun 2009 Karma :

yeah the holes towards the top will make quite a difference.
im not sure on the specifics but its something to do with the flow blah blah mumbo-jumbo (technical term).

turn them round and get it dyno'd again. should be fine Thumbs Up

chances are if you paid the guy 55, he would have taken the bike apart, seen they were upside down, turned them round and then just gave it back. £55 for a 30 min job is a bit steep.

let us know how you get on? Very Happy

hope this helps. Carl.

D O G · World Chat Champion Joined: 18 Dec 2006 Karma :

Before we all start lamping into Doubletake (not that we are, yet - hence the 'before'), I dealt with these guys a fair bit when I lived in Southampton, since they were local to work. Knew others who did the same, and never had a problem at all. They sorted out a very annoying problem on my SRAD and certainly didn't charge excessively.

They are always horrendously busy however, which may have a bearing on their price in this case.

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Yeah I thought the fact that it took me two hours to find one dyno place might suggest their prices would be a little higher!

Although I'm sure Carl is right, if I obviously didn't know the washers were the wrong way up he'd take my money and flip them leaving me none the wiser!

Other than that they've done nothing wrong really, I was just a little worried I might have been getting ripped off and this is my best place to come for advice!

I'll get the washers turned round sometime in the next few days and post here with the results!

Thanks again!

D O G · World Chat Champion Joined: 18 Dec 2006 Karma :

Rather than dynoing it after you flip the washers, just ride it - you should notice a 50% power increase. If it feels faster, then job is done, no point faffing on and spending more money just to get an extra couple of bhp.

Wafer_Thin_Ham · Super Spammer Joined: 18 Nov 2005 Karma :

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Handsome · World Chat Champion Joined: 30 Dec 2005 Karma :

Alex_H · Borekit Bruiser Joined: 28 Jul 2009 Karma :

Its 30 bones where I go too, and the guy even tells you what you can do to your carbs to get a few more bhp! Even better was that he was right lol.
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1998 r1, ccm 644 ds, 2000 r6 ghetto track bike

iooi · Super Spammer Joined: 14 Jan 2007 Karma :

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

I would put them cylinder-side, as far from the carbs as possible to minimise turbulation through the carburettor choke. It's just my opinion.
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132.9mph off and walked away. Gear is good, gear is good, gear is very very good Very Happy

Charlie · World Chat Champion Joined: 27 May 2007 Karma :

£25 for me about 2 years ago, straight power run

I have since removed my restriction washers, mine where mounted very close to the carb. I'd listen to Geri though.
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carlperkins00... · Crazy Courier Joined: 16 Jun 2009 Karma :

Mine were carb side on the hornet 600.
I dont suppose it would matter that much to be honest.

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Cool, I guess if they're carb side they're not gonna get sucked out, not likely that they would anyway, but this way they're being pulled against something rather than away from it! I'll get that done today!

Pickledswede · Traffic Copper Joined: 15 Jul 2008 Karma :

Right, all sorted! Took me about an hour, when it took ~5 hours with me and my brother doing it!

0-60 seems faster now, and I've had 90 out of it, but these were both down a hill, didn't seem to want to go anywhere after 90 so I'm inclined to think that's all it's got!

Thanks for the help guys!