Honda GX200 exhaust question.

[T i m]

Hi All,

I've just picked up a second hand GX200 powered 3KVA genny and there is what looks like a fine mesh disk rattling about in the actual exhaust outlet. It would fall out but it's otherwise trapped by the other heat shield.

I think the PO suggested there may have been an additional outer deflector on the exhaust box and I'm wondering if that also had something to do with holding whatever_this_is in place?

Does anyone have such an engine and know how that area is supposed to go together please?

If there are some bits missing, would you know if they are available separately, if not, would one of the aftermarket exhausts on eBay be ok (ok = no noisier and give full power etc).

On that and if I am going to get a new exhaust anyway, I have here a fairly new exhaust off a 125cc 4/ scooter [1] that, with a bit of tweaking and in the spirit of d-i-y etc could be made to fit within the general genny frame (it's an open cage type). Would you think this might be quieter than the stock exhaust, if bigger is better it should be and as I already have it etc?

Cheers, T i m

[1] I think the (125cc) scooter did about 8K rpm and this (200cc) Honda does about 4k rpm so I don't think the exhaust would be two restrictive.

[spamlet]

I have no idea about the innards of modern bikes or their exhausts, but exhausts are *supposed* to be designed so that any pressure waves set up in them assist rather than interfere with the smooth working of the engine. Each could be said to be 'tuned' for the engine it was designed for. That said, it has never stopped people going for appearance rather than power and quietness... - or indeed stainless rather than instant rot and cost a fortune standard items.

S

[T i m]

True, although I think that may apply more to 2/'s than 4/'s

And even tuned further on that particular engine and it's tuning. When I used to race power RC catamarans a few mm on (or off) the length of the exhaust could make a big difference.

The 'factory stock' (stainless) exhaust supplied when we built the kitcar was *way* too noisy for me so I fitted a slightly shortened ss aftermarket std Escort one (Grundy?). Been on there over 20 years now. ;-)

My thought on this genny was that the stock exhaust wasn't very sophisticated (like a lawnmower jobby) and whilst ok a tickover was quite loud under any real load. If I'm going to replace the exhaust with a new stock one (this bit rattling makes it annoyingly noisy as well) I might saw the box off the stub and try tack the scooter one on with some silicone tube and see how it works.

The thing is I don't know how much mechanical noise is coming from the engine itself but if I port the exhaust away from the unit a bit I might be able to soundproof it a touch.

Cheers, T i m

[spamlet]

:-) There's me showing my ignorance again: after a garage full of bits on numerous occasions Honda to me means bike: should have googled first! Anyhow, always admired the insides of the Hondas, and I expect the general purpose engines are just as good. I can't seem to make their parts list let me in (probably a cookie thing), but you can get a manual here if it might be useful:

like plenty of scope for kits with these things if one consults google images.

Cheers, S

[T i m]

Me too. I have a little CB 'Two Fifty' and it starts first press every time. But then I've always had luck with Yamaha kit. I have a little

2hp Yamaha outboard that weights nothing yet used to put my 14' sailing dinghy on the plane when one up. ;-)

after getting the beasty. Looking at it again though it does show a little tail pipe that might be what is missing on mine.

Yeah, one of the reasons I was interested in this particular genny (I had the choice of 3) was *because* it was powered by this Honda engine. Nothing more comforting to stick Honda GX200 into eBay or Youtube and be inundated with hits. ;-)

If I can get the parts manual my local bike shop can get parts for me with a bit of discount.

Cheers, T i m

[ransley]

the screen would be a fire-spark arrestor, they clog up and reduce engine performance dramaticly, remove it unless you use it near something that can burn, [ but you dont do that anyway. right]. I remove my spark arrestors, Ive had motors nearly not run until they were removed.

[geraldthehamster]

I don't think the type of exhaust would make a huge difference to a small single cylinder engine.

I've been thinking of fitting a silencer off a bike to my Yard Man mower. I've never understood why bike exhausts have been subject to noise restrictions for decades, but lawnmowers have not. Just think how much quieter Sunday afternoons would be.

cheers Richard

[T i m]

Ah, thought it might be.

Ok.

;-) I don't but there's a possibility it might be going up to Scotland where my daughter could use it for power tools when finishing her chainsaw carvings. Would being covered in sawdust and wood-chipping's be considered a fire risk? ;-)

Funny you should say that. I went round my BIL's a while back and he was having issues with a petrol strimmer (lack of power, wouldn't rev out etc). Once he recapped what he had already done and being familiar with 2/ motorbikes I investigated the exhaust. As you say, it (fine mesh) was bunged nearly solid and a good clean fixed it nicely.

Since posting I've found a parts manual for said engine and it looks like the spark arrestor should have been held in via a small screw from one side. The missing bit on the outside of the heat shield just looks like a pressed steel contoured baffle, generally sending the exhaust gasses downwards.

interesting (for me) though is I have also found Honda do a 'quiet muffler', all be it for the bigger / V-twin models but it looks very much like the scooter exhaust I have here.

Like this:

Also it seems they may do short exhaust stubs that could fit my model (for other exhaust variants) that would make the task of trying the scooter exhaust much easier.

GX160 seems to share many parts with the 200).

Or I can buy a 'performance' flange and make my own pipe manifold. ;-)

carbs, con rods, all sorts of goodies. ;-)

T i m

[spamlet]

You said it! It would be nice to have at least one day a week when we could actually hear the birds, and maybe even a bee or two. I know there are a lot of chainsaw enthusiasts out there, but do I have to hear them *every* day? Even a 'quiet walk in the woods' is often (well was really, I'm a bit stuck in the house now.) an ear splitting experience these days. Don't they have a ban on 'Sunday noise' somewhere? Germany?

S

[geoff]

In message , spamlet writes

Yup - disturb the peace on a Sunday in Krautland and you get a knock on the door from the boys in green

[T i m]

"And where would we be if there were too many rules ... ?" ;-)

I guess there is a lot of NIMBY no matter what it is.

Like the other day, I know when we are having a flash of summer out there as my eyes start stinging (indoors) from BBQ fumes blowing in from all around.

Luckily we have a adequately equipped kitchen so we don't have to go though all that 'burning it outdoors with the flies' nonsense. ;-)

When we first moved into this area we were one of the youngest couples on the block and *we* were the only ones not making the loud noises or mowing / trimming / strimming at the crack of dawn every Sunday.

Luckily as the old folk have all died off the youngsters have replace all that garden / lawn nonsense with gravel and slabs so it's just the kids on the trampolines and the odd ghetto blaster we have to put up with (but not normally till the latter half of the day).

I even bought an electric chainsaw for daughter to try for small carvings to see if that would be acceptable noise wise but it was too loud by our judgment.

Cheers, T i m

P.S. Geoff, I used that wheel cleaner chemical again today on a second hand hdd caddy I bought for my laptop. It looked like it had some water damage / corrosion on it and after a quick wash in the sink with some of that gear diluted 50:50 it looks like new again. ;-)

[geoff]

Good stuff, innit

[Dave Liquorice]

That's one thing I hated about the suburbia of St Albans. The stench and smoke haze of burning meat when ever the sun came out. Last time we suffered that here was in 2001 from the F&M pyres 20 miles down wind...