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Honda Melody Running Slow

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Hunni
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Joined: 01 Jul 2018
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PostPosted: 04:48 - 02 Aug 2018    Post subject: Honda Melody Running Slow Reply with quote

Hi All,

I have recently had my throttle cable replaced and now my Melody only runs at a maximum of 20mph.

Of course there's more to this problem.

The garage i took her to (yes, she's female) noticed that her carb was only held on with 2 screws (bolts?) and sorted that out too.

Before the repairs I was able to get around 25 - 27mph out of her. But now (even downhill) I can only get 20mph.

When travelling downhill, it feels like there is a restrictor in place, as it feels like she is pulling back. When going uphill or running on the flat she runs at a steady 20.

I'd be grateful for any help or suggestions.

Thanks in advance
Hunni
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fatjames
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PostPosted: 13:10 - 02 Aug 2018    Post subject: Reply with quote

I'd go straight back to the people who did the work.
Explain the problem and discuss how they plan to remedy it.
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MCN
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PostPosted: 14:30 - 02 Aug 2018    Post subject: Reply with quote

Defo female as 'she' sounds like a proper biatch.
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WD Forte
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PostPosted: 20:11 - 02 Aug 2018    Post subject: Reply with quote

Yep, take it back.
I'll guess that when they fitted the new cable they didn't check the throttle operation properly and it's not fully opening up.
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The Shaggy D.A.
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PostPosted: 20:20 - 02 Aug 2018    Post subject: Reply with quote

fatjames wrote:
I'd go straight back to the people who did the work.
Explain the problem and discuss how they plan to remedy it.


/thread.
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Teflon-Mike
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PostPosted: 00:06 - 03 Aug 2018    Post subject: Reply with quote

Hunni wrote:
I have recently had my throttle cable replaced and now my Melody only runs at a maximum of 20mph.

Obviouse suggestion is that the cable is a) the wrong one; b) been fitted wrong c) Not adjusted.
Cable tuggs carb slide from closed to open; further open it is, faster you should go, so if cable not lifting slide the whole way, top speed wont be achieved.
Hunni wrote:
The garage i took her to (yes, she's female) noticed that her carb was only held on with 2 screws (bolts?) and sorted that out too.

That sounds suspicious... I dont recall a carburetor mounting up on more than two studs...

quick look at CMSL and the Aerox moped seems the closest match, also shows conventional carb held on with two studs and nuts... plenty of screws in the carb... four of them hold the float-bowl on to it..

This could be just a mechanic trying to keep explanation simple... or could be trying to justify a rip off.. or they might not have a clue what they are doing....

What sort of garage is it?

You seem to be down in the Pirate Peninsula, where franchise dealers and specialists are a bit thin on the floor. B-U-T in a world of improvisation, that could actually work in your favour. Melody Moped has more in common with a boat's out-board motor, or garden strimmer, or chain-saw than it does a Ford-Focus; but, many paid mechanics are loath to work on bikes, particularly small bikes, more so old bikes, and especially 'economy-commuters' where owners resent spending anything on them, and any bill more than the cost of a tank of petrol is likely to end in argument.

And a Y-Reg Melody? I think they were making them in '82 when 'Y' Plate came around the first time, but even a late one would be a 2000 model, and old enough to have its own driving licence! It's a bike, its an old one, its a small one, and its an economy commuter... I'm surprised any-one had much interest in tickling it with spanners TBH!! The odds are against it!

If you use a paid mechanic you need to have confidence in them knowing what they are about. And if the bike comes back from them with more problems than you took it to them with? Doesn't give much confidence does it?

As said, Melody Moped has more in common with an out-board motor, or a strimmer; its prety crudimental simple as they come!

It has a two-stroke engine, with essentially just three moving parts; the piston, con-rod and crank, and AFAICT it's an even simpler air-cooled piston-ported variety that doesn't even have a reed-valve or anything.

The transmission, is a little less sophisticated than many scooters that employ centrifugal clutch and expanding pulley belt drive; it just had a row of idler gears between the crank-shaft and the tiny back wheel to transmit motion, so even lacks a belt to snap or a variator to jam up.

Does beg the notion that any-one should be able to fix one of these things pretty readily, and if the cant.. they either haven't got the first ounce of savvy, or just aren't trying!

So... go back to mechanic and yell at them 'till they sort it... if they weren't trying... it might motivate them.... if they hadn't got a clue to begin with? Probably just give them chance to eff-up a bit more... your call!

Personally; given how dang simple the thing is, I'd just get a Haynes manual and a halfords my-first-tool-kit, and start from scratch.

Actually how I started mechanicking, aged 10, with a Batavus Step-Though pedal and pop... and I didn't even have a Haynes for the thing... I was given a 'Shell - How the engine works' lady-bird book, that had fantastic pictures showing how the four-stroke engine worked; and a Vespa 'Owners Hand-Book'.. which was only slightly more helpful, telling me where to put the petrol, and check a spark plug! I learned! Eventually!

Hunni wrote:
When travelling downhill, it feels like there is a restrictor in place, as it feels like she is pulling back. When going uphill or running on the flat she runs at a steady 20.


Well, AFAIK, there's NO restrictor on a melody moped. Moped restrictions of old, said 3 1/2 horse-power, 35mph. Modern euro-borrox call for I think its a 27mph maximum design speed. Usually achieved by the expedience of just NOT making the power to go any faster, without the added complexity of anything to actually limit that power, just a crudimentary engine design that wont make any more! ~No magic washer in the exhaust, no fancy electronic box on the ignition, no clever travel limiters on the variator, you dont have anyway! Its slow, just 'cos its SLOW!

But 20mph would seem a tad slower than normal.

Most likely suspects as suggested, are the throttle cable you originally identified as at fault. Is it the right cable? Is it correctly fitted, is it actually allowing full throttle slide travel?

Mechanic muttering of missing carb screws? Offered hintimation they have fidled some-where else.... but who knows what or where... so check the cable first.

Then check that the throttle slide is fitted the right way round; and check that the idle screw is set properly.

Not going faster down hills... is a bit curious... with gravity assistance, even on a pretty dire motor, I'd expect it to coast that fast... going up them would be more illuminating, and could point to worn slippers or springs in the centrifugal clutch, if the engine screamed its nuts off and bike only crawled up the hill under load....

Otherwise; sends you back to basics, and start with that carb-cable.... then the spark-plug; and its ALL in the Haynes; read, set to book, follow the instructions, use the fault-finding tree; and drill down layer by layer, eliminating possible problems, fixing obvious, then less obvious ones as you find them; until you have nothing left to fix.... and as said... there REALLY isn't much too these little things, more moving parts in an kids stocking filler salt-water car or hover craft kit from Maplins! It really ISN'T rocket science... and I used to develop missile guidance systems for the military.. I should know! (And you'd be aghast at how 'unscientific' most rocket 'science' actually is; if you were to have seen us launching pop bottles up the car-park, or playing cleaning lady closet 'Ice-Hokey' with a couple of brooms and a state-secret electronic assembly, on the low-friction lino of the works canteen, after hours! YES these were actually official missile development 'tests' Lol!)

Asking us? A wealth of mechanical know how on tap? BUT we are working by voodoo... we dont have the bike before us, we REALLY don't know what's wrong with it; we are just guessing. DONT GUESS.. DIAGNOSE.... its all in the Haynes; just follow the instructions, and be methodical and systematic; you'll find the fault, you'll probably fix the fault, and you'll learn a lot along the way, and have satisfaction of not paying a mechanic, and knowing you have done a good job.
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The Shaggy D.A.
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PostPosted: 08:38 - 03 Aug 2018    Post subject: Reply with quote

What Tef's trying to say is he doesn't know either. You've paid someone for the work, it isn't right, first port of call is getting them to correct it.
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Hunni
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PostPosted: 21:51 - 03 Aug 2018    Post subject: Reply with quote

Thanks for your help guys,

I will be taking her back to the garage when they re-open on Tuesday (local bike show and bank holiday).

I will let you know how I get on.

ttfn
Hunni
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Hunni
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PostPosted: 18:16 - 09 Aug 2018    Post subject: Reply with quote

So not happy.

It would appear that the person I bought my Melody from, deliberately loosened the carb, so more air could get in and give the speed an artificial boost... at least that's the explanation I was given.

When I had the throttle cable put in, the garage also put that ""right"".

I asked if they could put it back as it was ... and they said no (for legal reasons, which I can't blame them for)

So i'm stuck with a lemon... caveat emptor indeed. Mad
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WD Forte
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PostPosted: 18:43 - 09 Aug 2018    Post subject: Reply with quote

It would appear that the person I bought my Melody from, deliberately loosened the carb, so more air could get in and give the speed an artificial boost... at least that's the explanation I was given.

That sounds like total bullshit to me.
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Teflon-Mike
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PostPosted: 01:20 - 10 Aug 2018    Post subject: Reply with quote

A two-stroke engine is a miracle of engineering.
Its a bloomin' miracle they even work at all!

Significant thing is, that they use crank-case induction. The cranc-case chamber beneath the piston has to be 'sealed' so that as the piston rises on the 'up' stroke, it sucks the charge into the crank-case; then on the 'down' stroke, the piston squashes the charge in the crank-case, so that when the piuston falls beneath the 'transfer-ports' opening them, 'some; of that pressure pushes charge into the cylinder.

Thing IS, that the piston sucking and squashing charge in the crank-case, it aught to shove whatever it sucks in, back out the way it came in!

Only reason it doesn't, is the curiosity of 'flow' and the fact that once moving air has momentum, and would rather like to keep moving in the direction it's going, rather than stop, turn around and go the other way.

It's also rather curiouse that the 'charge' if it makes it through the transfer ports, doesn't either just start burning the moment it meets the burning charge in the cylinder from the last cycle, or just follow that burnbing and burnt charge out the exhaust port with it!

They are strange and curious contraptions!

It was, the genius of Walter Kaaden, in East Germany, working at the old DKW factory, renamed 'MZ' after Soviet occupation, that tackles these issues on the pre-war DKW RT125 engine, and fitted a 'disc-valve' to the crank-case, so that the inlet port was 'open' as the piston rose, and 'closed' when the piston fell, stopping charge sucked in as piston went up, being pushed back out the way it came on the piston came back down, who created the 'Hi-Performance' two stroke.

In the 1950's, this little innovation almost doubling the trapping efficiency of the engine in one swoop; meant that the little DKW RT125 engine went from about 4bhp to 7bhp, almost rivaling the power per cc of positively valved four-stroke engines, and allowed Kaaden to go on and start 'tuning' the engine with more aggressive port timing for more still, allowing the 2T to actually exceed the power per cc of the 4T, through the 60's, 70's and 80's and into the 90's.

ANYWAY! As far as I can tell, the melody moped, uses the early 'un-valved' piston ported arrangement of the original DKW RT125.. because its cheap, simple and needs less parts, and who cares if the thing is only allowed to make 3bhp anyway.

And IF the carborettor was 'loose'...... it shouldn't bludy RUN!

If the lack of seal let more air in.... it wouldn't get in via the carb carrying fuel with it.... it would be fresh air not charge, so it aint gonna make a 'bang' to start with... A-N-D that lack of sealing would mean that anything that did get sucked in, would be even more want to bugger off back out the way it got in, not go where its supposed to into the cylinder!

SOMEWHERE something AINT RIGHT!

And at this moment, finger of suspicion is pointing very much at that mechanic!!!

Legal reasons? What bludy legal reasons? He's a mechanic not an effin lawyer! Neat bit of nebulous authority to dodge doing what customer asks though!

He's a mechanic; he twiddles spanners, when asked by a customer. You customer... and he who pays the piper!

Oh-Kay....

So chap wont undo the carb as you asked... that might actually not be such a bad thing; it IS a stoooopid idea! But still... excuses are good... Does he make a living on the side writing fiction novels by any chance?

So... throttle cable; correct one; correct assembly, correct adjustment.... and Chap says he did job 'right'... you say bike don't work propperly, so cant be right; he says well tough.... and you are at am impass.

Shrug it off... cart load of pure bovine excrement chucked into the deal, REALLY doesn't give much confidence that you would get anything useful out the bloke, even if you won the argument, or chucked more money at the fella, and likely letting him anywhre near the thing with a spanner would just give you even more problems and potential arguments, and excuses, for the money and trying!

SO... go buy a Haynes Manual, go get some spanners; DIY.

Read the book; follow the instructions, KNOW what is done to the thing, and why, and WHEN you fix it, have satisfaction of having done a good job... unlike the fiction author talking about loosening carbs for more power and laws stopping him twiddling spanners, when that's his 'proffession'!!!!

OR, give up on it as bad job; slap on e-bay spares and repairs, and go look for something else.

Thems your choices.
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sickpup
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PostPosted: 13:38 - 10 Aug 2018    Post subject: Reply with quote

Its more than likely worn rollers.
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Teflon-Mike
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PostPosted: 14:33 - 10 Aug 2018    Post subject: Reply with quote

sickpup wrote:
Its more than likely worn rollers.

Does the Melody Have any?
Schematics I found didn't even show a reed~block, unless its hidden cunningly in the inlet manifold; and simple centrifugal slipper clutch and allgear drive to the driven wheel.
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stevo as b4
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PostPosted: 18:04 - 10 Aug 2018    Post subject: Reply with quote

Of course it'll have a variator of some description and belts as well as a gear final drive. With no way of varying the gearing how in hell could a 49cc low revving under 3bhp be able to do both pulling away from a standstill and accelerate to a terminal 30mph ish? Your going to need a decent range of gearing to do both of these things on a 50.

If OP is getting full throttle and has actually checked, then it's going to be a gearing or transmission issue most likely. Of course a compression test and making sure the exhaust system and port are free from a large build up of carbon would we worth ascertaining too.
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WD Forte
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PostPosted: 19:02 - 10 Aug 2018    Post subject: Reply with quote

We don't know the year, (Melodys are early to mid 80s?)
mileage, condition and history.

Online diagnosis is best guesses at best but if we take
Before the repairs I was able to get around 25 - 27mph out of her.
Which sounds about right for what it is.
at face value and
But now (even downhill) I can only get 20mph.
as true then the nonsensical statement of deliberate inlet air leaks for 'moar powah' makes me wonder if the garage knows wtf it's doing.

It's quite possible a previous owner has fiddled about trying to get
a bit more oomph out of it but you'd expect any half decent mechanic would be able to at least diagnose and hopefully correct it,
not make it worse.
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