2003 Honda Wave 100, is hard to start, idles rough, and when throttle applied it stalls at about 1500rpm.

 

Water in the fuel, bad spark? I am a semi-qualified Shade Tree Mechanic, and would appreciate any thoughts before I tear into it.

My first thoughts?

 

Check the spark plug.

Check air filter if here is still one.

Buy a bottle of fuel system cleaner bung some into the tank and let it idle for 15mins or more then let it stand for a few hours. Then try again. 

 

Replace the spark plug and the spark plug cap.

 

    Remove the plastic shi_e and check if there's a vacuum controlled valve that lets fuel through when the engine is turning.

 

Check if the fuel contains water, if so let all out. 

 

     Take brake cleaner or starter fluid and spray it around the carb. If the RPM's got up, you've got a vacuum leak.

 

  Anyway time to overhaul the carb, it's an easy job. 

Just now, teacherclaire said:

Replace the spark plug and the spark plug cap.

 

    Remove the plastic shi_e and check if there's a vacuum controlled valve that lets fuel through when the engine is turning. ( Just follow the fuel line)

 

Check if the fuel contains water, if so let all out. 

 

     Take brake cleaner or starter fluid and spray it around the carb. If the RPM's got up, you've got a vacuum leak.

 

  Anyway time to overhaul the carb, it's an easy job. 

 

Some villages water down their fuel, relying on the ethanol content to hide the scam.

Easiest way to clear water from a tank is to add methylated spirits, to restore the fuel to a single liquid phase.

As other posters have suggested, drain the fuel is another option. However, rinsing the system with methylated spirits will work better, as separated water tends to stick to any rubber or plastic.

When did you have the last service on this bike? Do you use this bike frequently?

https://www.manualslib.com/manual/826702/Honda-Wave-110i.html

Consider (check, clean or change):
* Spark plug,
* Air filter,
* Carburetor.

Then, retest

1 hour ago, Shot said:

hard to start, idles rough, and when throttle applied it stalls at about 1500rpm.

Carburetor

Hard to start/rough running etc. when hot or cold?

 

If when hot >> Choke stuck open?

 

Excellent information, much thanks to all. I'll start with the easy stuff (fuel system cleaner, spark), and go from there. I'll let you know what I find.

37 minutes ago, Fab5BKK said:

When did you have the last service on this bike? Do you use this bike frequently?

https://www.manualslib.com/manual/826702/Honda-Wave-110i.html

Consider (check, clean or change):
* Spark plug,
* Air filter,
* Carburetor.

Then, retest

I picked this bike up a few months ago for a 3k Baht, it ran fine at the time, but I don't know the history. It's old, ugly, rusty, plastic is cracked, but I love it. 

I have a 2001 Dream which has the same engine and carb.  Owned it from new.

 

Nine times out of ten if there is a problem it is dirt or contaminants in the fuel.

 

Remove carb.  Strip carb and clean.  Make sure jets are not blocked.  Put it back together.  Check fuel filter and replace if necessary.

 

 

51 minutes ago, Kwasaki said:

Carburetor

+ spark plug and eventually vacuum leak(s).

51 minutes ago, teacherclaire said:

+ spark plug and eventually vacuum leak(s).

Well his symptoms are typically Carb. 

It wouldn't start and idle if it were plug. 

The idle jet is the problem, so clean the Carb,  change fuel filter if there is one. 

if it's a SV Carb a split diaphragm can cause much same. 

 

51 minutes ago, Kwasaki said:

Well his symptoms are typically Carb. 

It wouldn't start and idle if it were plug. 

The idle jet is the problem, so clean the Carb,  change fuel filter if there is one. 

if it's a SV Carb a split diaphragm can cause much same. 

 

Just cleaning doesn't help much. After such a long time, he should rebuild the carb.

It's not a Constant Velocity carb, it's an ordinary carb and a Kit pretty cheap.

 

65 baht for a kit if it's a Keihin.

https://www.lazada.co.th/products/honda-wave100-wave100r-wave100s-carburetor-repair-kit-i1190116895.html

   

 

   

Good call, I commented on OP post symptoms as that's what I would say is the problem.

7 year Carb not old, just a clean and as you say a Carb refurbish kit.

3 hours ago, Shot said:

Excellent information, much thanks to all. I'll start with the easy stuff (fuel system cleaner, spark), and go from there. I'll let you know what I find.

Don't forget to check spark plug cable. If it fires on minus/ chassis/ engine you will face serious issues. And I've just replaced the spark plug cap on our 19 year old Yamaha Best II.

 

  It had almost no resistance and we always had a hard time starting it.

 

   50 baht and you get a new one. 

 

 

Personally I would go with genuine parts if they are needed; particularly with precision parts like jets and needles and rubber components.  I know for sure that the genuine rubber parts can cope with gasohol.

 

That said I think it unlikely anything will need replacing.  Maybe the float bowl seal and I vaguely remember at least one time I gave up on trying to unblock an idle jet on some bike or other.  

 

A fair percentage of the stuff in that Lazada kit is make-weights that you are highly unlikely to need.

43 minutes ago, In the jungle said:

Personally I would go with genuine parts if they are needed; particularly with precision parts like jets and needles and rubber components.  I know for sure that the genuine rubber parts can cope with gasohol.

 

That said I think it unlikely anything will need replacing.  Maybe the float bowl seal and I vaguely remember at least one time I gave up on trying to unblock an idle jet on some bike or other.  

 

A fair percentage of the stuff in that Lazada kit is make-weights that you are highly unlikely to need.

But it's only 65 baht and he can use certain o-rings. 

4 minutes ago, teacherclaire said:

But it's only 65 baht and he can use certain o-rings. 

 

That is a fair point and I probably should remember that he only paid 3000 for the whole bike!

Just now, In the jungle said:

 

That is a fair point and I probably should remember that he only paid 3000 for the whole bike!

Only? That depends on the bike. If the engine is almost dead and the frame, brakes and other parts, it might cause many visits to these super Mario mechanics who never fix what's causing something to stop working.

 

I don't trust any of them since one had destroyed the engine of a 2 cyl. big bike by not knowing how to tune the carbs.

 

I can believe that.

 

The secret of my success with bikes in Thailand is that I do everything myself.

 

The only thing I trust bike shops here to do is swap tyres and even then I take the wheels out myself.

6 minutes ago, teacherclaire said:

Only? That depends on the bike. If the engine is almost dead and the frame, brakes and other parts, it might cause many visits to these super Mario mechanics who never fix what's causing something to stop working.

A small
Honda bike taken to an official Honda dealer will be well taken care off.

Most mechanics can do these bikes blindfolded.

1 minute ago, jvs said:

A small
Honda bike taken to an official Honda dealer will be well taken care off.

Most mechanics can do these bikes blindfolded.

A close relative "studied" electronics at the technical college. But he didn't learn much and he couldn't tell you what a capacitor does. So much to their education. 

 

Same education for the mechanics here. They only learn by doing mistakes. If so. 

5 minutes ago, In the jungle said:

I can believe that.

 

The secret of my success with bikes in Thailand is that I do everything myself.

 

The only thing I trust bike shops here to do is swap tyres and even then I take the wheels out myself.

Welcome to the club! I have all tools to fix an 1100 cc and would never trust a mechanic here again. And I mean never. 

 

   I was at a Honda dealership, because I didn't have the right tool to take the upper screws out where two mechanics helped me for free just to learn how to change front fork seals on a big bike.

 

  They didn't understand how a foreigner knows so much about this topic. 

 

 

1 hour ago, In the jungle said:

Personally I would go with genuine parts if they are needed; particularly with precision parts like jets and needles and rubber components.  I know for sure that the genuine rubber parts can cope with gasohol.

 

That said I think it unlikely anything will need replacing.  Maybe the float bowl seal and I vaguely remember at least one time I gave up on trying to unblock an idle jet on some bike or other.  

 

A fair percentage of the stuff in that Lazada kit is make-weights that you are highly unlikely to need.

What about a new O-ring for the pilot screw?

5 hours ago, Shot said:

I picked this bike up a few months ago for a 3k Baht, it ran fine at the time, but I don't know the history. It's old, ugly, rusty, plastic is cracked, but I love it. 

Missed this, maybe fuel tank flush will be a good thing, inline fuel filter if it it ain't got one.

Bet you find carb dirty and partially blocked jets.

Wave are like toys cheap and easy to fix.

 

50 minutes ago, teacherclaire said:

What about a new O-ring for the pilot screw?

 

Maybe.  My main reservation with aftermarket rubber carb parts is how well they will cope with gasohol.  I know the factory rubber parts are OK but I have never tried aftermarket.  Something like the O ring for the pilot screw is not immersed in fuel so I think it would be fine.

 

 

19 hours ago, In the jungle said:

 

Maybe.  My main reservation with aftermarket rubber carb parts is how well they will cope with gasohol.  I know the factory rubber parts are OK but I have never tried aftermarket.  Something like the O ring for the pilot screw is not immersed in fuel so I think it would be fine.

 

 

Considering the age of the bike, it's worth to change the O-ring. Rubber wears out over the years. Also a new float and valve would be great, including gaskets and O-rings. 

Here we are 5 weeks later, and I finally got around to repairing it. I had some spark, but the plug was dirty so I replace it. Water and some dirt in the tank, I purged that and replaced with clean fuel. Eventually, I'll clean up the carb but for now she runs like a champ. Thanks for all the tips. 

 

Let'er rip, tater chip. 

19 hours ago, Shot said:

Here we are 5 weeks later, and I finally got around to repairing it. I had some spark, but the plug was dirty so I replace it. Water and some dirt in the tank, I purged that and replaced with clean fuel. Eventually, I'll clean up the carb but for now she runs like a champ. Thanks for all the tips. 

 

Let'er rip, tater chip. 

I hope that you made an oil change. Our little 110 Yamaha has 72,000 km on the clock, not one part of the engine was yet replaced. And it runs like hell. 

 

But only because we service the bike and if something breaks down, it will immediately get fixed by me. Same goes for the pick up and the bigger bike. ( Not trying to be a cheap Charley here,..)

 

You can use spark plugs forever when you adjust the gap from time to time. 

 

The carb is so easy to tune. Turn the air/fuel mixture screw slowly in until the bike runs bad, then slowly out until it runs great. Job done, no mechanic needed. 

 

   The other screw changes the RPM's, couldn't be easier to tune them.