How to adjust Honda Wave Carb?

[ricklev]

I have a ten year old Wave.  It will only run when half decently with the choke all the way out.  It wouldn't stay running at all really and I had the spark plug replaced and the carb cleaned but now it only runs moderately well with the choke full on till it gets warm and even then not so good.

 

I live on Rajadamri by the Rajadamri BTS and there is only one shophouse shop close by and they clearly don't have the smarts or perhaps interest to spend more than a minute thinking about it.  When I objected to the way it was running after he replace the plug he grabbed the throttle, revved it up to a speed that knocked a couple of years off the life of the engine and proclaimed it fixed. 

 

I don't like to ride it in Bangkok so I don't want to ride it to a better shop.  Just keep it for grocery runs (and red shirt/yellows shirt protest that shut down my soi to vehicles).

 

I'm thinking maybe the carb just needs adjusting?  I never found a manual in English so I have no idea how.  There are two screws, one with a spring and one without a spring? 

 

I know I'm supposed to back of one and then....... Any instructions would be much appreciated!

 

 

 

 

[In the jungle]

The one with the spring is idle rpm.

 

The one without spring is idle air/fuel ratio.

 

But I doubt adjustment is the solution.

 

Sounds to me like you got a half-assed job in terms of cleaning and checking the carb.

[In the jungle]

Checks that you did not mention include:

 

1.  Carb float height

2.  Air filter

3.  Fuel filter

[ricklev]

Yeah. New air filter and fuel filter recently and the last time they cleaned  the carb I think they replaced the float. It was running bad then but worked ok for awhile. That was about 500 kilometers ago.   After that time I noticed there was gas leaking out the base of the carb so they had to fix it again.

 

Its foolish for me to take it back there but it's convenient and I don't guess they are overcharging me. 

[Strange]

2 minutes ago, ricklev said:

Yeah. New air filter and fuel filter recently and the last time they cleaned  the carb I think they replaced the float. It was running bad then but worked ok for awhile. That was about 500 kilometers ago.   After that time I noticed there was gas leaking out the base of the carb so they had to fix it again.

 

Its foolish for me to take it back there but it's convenient and I don't guess they are overcharging me. 

 

Buy a new carb. You will have better luck with a base tune carb than getting somchai to wrap his head around it. 

 

It might not be the carb though, people always assume it must be the carb when things are running like a turd and a lot of the time its ignition. Thats probably even more difficult to get somchai to understand. 

 

I think you said the bike in question is 10 years old? Might be time to trade it in on a newer model in all honesty. Diagnostics are pretty hard without knowledge. 

 

That bike plus 10-15K will get you something good. 

[ricklev]

Thanks for the suggestions!

 

Yeah.  I plan on buying a fairly new used Click or PCX.  I've been waiting for something convenient to be for sale. Considering I only ride it 500 kilometers a year or so the Wave did what I needed for many years.

 

I usually spend a few weeks a year in Chiang Mai and I mail it there so it does get some use.

 

It could be the ignition.  I've never had the valves adjusted either.   Maybe next time I'm in Chiang Mai I'll try to find someone competent.

 

I had thought of buying a new carb but it would involve riding it to the closest Honda shop or a decent corner shop (which I still haven't located.......)

Edited November 28, 2016 by ricklev

[In the jungle]

Carb setting:

 

1.  Get the engine up to normal temp then set the idle rpm using the screw with the spring on it.  You do not have a tacho on a Wave so what you are trying to achieve is a stable idle.  You can get an idea of the right sort of rpm by listening to other Waves (ten on every street corner).

 

2.  Set the idle air/fuel ratio with the other screw.  Normally there is a base setting for this but I do not know what it is for a Wave.  A typical setting would be one and a half or two turns out from fully in.  Then try turning the screw further in (weaker mixture) or out (richer mixture) until you get the highest idle speed.  Bear in mind that this screw only affects mixture at idle and not throughout the range of throttle positions.

 

3.  Revisit idle rpm which probably went up as you adjusted the mixture.

 

Ignition:

 

The ignition system is very reliable and has no adjustment.  There is a small black box that controls advance/retard.  Check all electrical connections are good (just pull them apart and push back together cleaning if necessary).  I use a strobe light to check for misfiring throughout the rpm range but it is probably forty years old and not easy to find one here.  A strobe will also show you if the advance/retard is working.

 

New carb:

 

Not a bad idea and probably quite cheap.  Only consider a genuine carb that is correct for your model.  Any Honda dealer can supply.

 

Air leaks:

 

I think on your generation Wave the carb pushes into a rubber mount.  Make sure there are no splits or leaks from this part.  You can check for leaks using a small can full of petrol but I am not going to tell you how in case you sue me for the hospital burns unit bill :-0

 

Valve clearances:

 

I have never seen a Thai mechanic adjust valve clearances.  It's a little bit fiddly and you need a set of feeler gauges.  Inlet = 0.10mm.  Exhaust = 0.20mm.  I think.

 

Thai mechanics:

 

Generally speaking Thai mechanics are the problem and not the solution.  If the bike is not running right it's normally because they have screwed up.  Stripped threads and missing fasteners?  Thailand's finest at work.  On one rare occasion when I let a Thai mechanic touch one of my bikes the cost of the parts he broke exceeded the bill.  I do everything myself.

 

Good luck. 

Edited November 28, 2016 by In the jungle

[AllanB]

9 hours ago, Strange said:

 

Buy a new carb. You will have better luck with a base tune carb than getting somchai to wrap his head around it. 

 

It might not be the carb though, people always assume it must be the carb when things are running like a turd and a lot of the time its ignition. Thats probably even more difficult to get somchai to understand. 

 

I think you said the bike in question is 10 years old? Might be time to trade it in on a newer model in all honesty. Diagnostics are pretty hard without knowledge. 

 

That bike plus 10-15K will get you something good. 

 

Yes,  a new carb for a Wave must cost peanuts, unless you like tinkering....

 

I have been messing with the carbs on my NV400 for yonks, wish I could get a clean sheet. Fitted new float valves and still get an intermittent leak on one....god knows what else.

 

[KhruGin]

As others suggested a new carb, if indeed that is the problem. Was quoted 1,380 baht for a new carb for a 20 year old Dream some 5 years ago ...declined as bike was worth 5k tops ....reckon for a Wave it would be a similar price. Good luck.

[Richard-BKK]

Absolutely no need to change the carburetor, with modern fuel which contains around 10% ethanol you can have some problems that your engine idle speed is not perfect anymore.

 

The Honda Wave uses a Keihin carburetor and because if this it is a bit more difficult to adjust the idle screw, as it is hidden behind a metal prop. You can bring your motorcycle to a capable Honda dealer who will fix it in a few minutes or you can search on internet on “Keihin carburetor idle adjustment” and you can find a step-by-step guide how to adjust engine idle speed… Total cost of doing it yourself… 30 minutes

[canthai55]

If it will only run with the choke out, you have an air leak somewhere.  Air is not going thru the carb to pickup fuel. Pulling in air thru the intake manifold maybe - it is usually rubber so will crack with use. Making the mixture super lean, hence the need for the choke to be on to richen the mixture. Spray WD40 around, once it coats the leak it will start, at least for a short while. Will allow you to find out where it is sucking air in. Then repait.

[Strange]

The problem with messing with the idle screw is that if you play with it too much (wind it in too much) you take the carb off the idle circuit and onto 'part throttle' and everything gets all screwed up. 

 

If it only wants to run with the choke all the way on, then its too lean. The choke is restricting airflow and thereby enriching the air/fuel mixture. Either it is a carb fueling problem or there is an air leak like another poster said. 

 

If you buy a can of carb cleaner, get the bike running, and very carefully spray very lightly the rubber areas around the carb, manifold, etc, and the engine speed picks up you found the air leak. The engine will burn the carb cleaner like fuel and the RPM should increase if there is an air leak. 

[ricklev]

Well I took it to a Honda dealer today with the intention of just having them replace the carb.  I assumed that it would be around 1500 but they wanted 3000.  That made seeing if they could fix it right worthwhile.  

 

They cleaned it, changed the float again and adjusted it.  I asked them to replace the gasket.  I'm not sure if they did or not but the one they put in looked new and they said there were no air leaks.  

 

They did seem a bit more on the ball than the guys at the shop house and they spent about 1.5 hours working on it.  I can't argue with the 300 baht they charged.

 

  It ran OK on the way home.  

 

Thanks for everyone's help and suggestions.  

Edited December 19, 2016 by ricklev