Spark Arrester

[RayWebb1]

I live in wet damp England where forest fires are not exactly an issue, so I was thinking about removing the spark arrester. 2 reasons: 1, so that I do not have to clean it periodically as per the manual. 2, in case it frees up the exhaust flow a little, without upsetting the stock fueling or requiring any other adjustments. Any comments or experiences with this?
Many thanks, Ray.

 

[oldskool]

You may find this video interesting. I think those fellas that design engines for Honda may know what they are doing.

 

[RayWebb1]

Very interesting! I wonder if by making the exhaust slightly more free flowing it upsets the standard fueling. Anyway, that answers the main question and the spark arrester is easy/quick to remove for periodic cleaning.
My only other thought is what if you cut off just the spark arrester gauze end piece and put the rest of the pipe back in the exhaust? Maybe that would be better by maintaining similar back pressure? Of course it would mean cutting the pipe and if it is still worse than stock you have gone backwards! Has anyone tried that?

 

[oldskool]

Very interesting! I wonder if by making the exhaust slightly more free flowing it upsets the standard fueling. Anyway, that answers the main question and the spark arrester is easy/quick to remove for periodic cleaning.
My only other thought is what if you cut off just the spark arrester gauze end piece and put the rest of the pipe back in the exhaust? Maybe that would be better by maintaining similar back pressure? Of course it would mean cutting the pipe and if it is still worse than stock you have gone backwards! Has anyone tried that?

It's all FM to me. These newer systems seem to operate well if kept in "balance". Small changes can have unexpected outcomes

 

[m in sc]

that video is ridiculous, of course its slower, the efi didn't have time to adjust in 5 minutes or less, so until it adjusts its going to run lean, which takes a bit more time than dodging squirrels in the yard. will it give a higher tops speed? probably not much, again, the timing curve is the big factor at wot, but you will absolutely feel it improve in midrange when its allowed to adjust.

.

 

[oldskool]

So he will have a little louder bike that might have a slight improvement in midrange power. At what cost? A bit less MPG and a possible 1000 pound fine in the UK for running a modified exhaust if his bike is inspected?

 

[m in sc]

thats one hell of a British accent he has.

please, stop. A performance exhaust, or a spark arrestor being removed isn't going to hurt anything. No ones telling you to mod your bike, but plenty of us do with good results.

 

[oldskool]

I am not telling anyone how to spend their time and money. The fella is in the uk wondering if doing this is a good option for him. From what you have said he might gain a little midrange power. His bike will be a little louder. That little extra power has to come from somewhere so I imagine that will require more fuel? So that is what he might gain. What is also relevant is in the UK modifications to stock exhaust systems that make the bike any louder are illegal with fines up to 1000 pounds. Those are things for him to weigh and decide if it is something that he wishes to do. What am I missing? I regard these forums as pretty much talking to your neighbor over the back fence while having a beer. So as I would tell my neighbor that's what you get but this is what it might cost. It's up to him if it is worth it to avoid cleaning the spark arrestor once in a blue moon.

 

[m in sc]

I lost zero mileage before i swapped the pipe over. Been there, done it. also removed the catalytic converter in the headpipe at the same time. and UK guys run aftermarket exhausts on their bikes all the time. this helps scavenging which is more efficient overall. Thats just a fact.

 

[oldskool]

I lost zero mileage before i swapped the pipe over. Been there, done it. also removed the catalytic converter in the headpipe at the same time. and UK guys run aftermarket exhausts on their bikes all the time. this helps scavenging which is more efficient overall. Thats just a fact.

Aftermarket pipes are approved for use. Modified stock exhausts that are modified in any way making them any louder are not. He may want to leave things stock, he may want to invest in a approved aftermarket exhaust or he may want to take the SA out and hope for the best.

 

[TacoRocco]

I live in wet damp England where forest fires are not exactly an issue, so I was thinking about removing the spark arrester. 2 reasons: 1, so that I do not have to clean it periodically as per the manual. 2, in case it frees up the exhaust flow a little, without upsetting the stock fueling or requiring any other adjustments. Any comments or experiences with this?
Many thanks, Ray.

I'm in Canada and personally I don't want to be the guy that starts a forest fire for .01 hp, if that. The arrestor is there for a reason.

 

[RayWebb1]

Point taken. My son lives in Vancouver, so I appreciate what an issue fires are over there. Coincidentally he has a CT125 on order at the moment!

 

[RayWebb1]

And now, when I take a closer look at my exhaust silencer, it looks like the end cap is not even removable?! See photo.

 

[m in sc]

well, there it is. lol.

 

[dmonkey]

Looks like they updated the exhaust on the 2023 model and solved that dilemma for you

 

[jimzpsd]

I have to laugh at all these threads to modify these little bikes, keep in mind people its just a 125 cc. I get the tinker/fun factor, but to make it "better or stronger", lol. Maybe look into a bigger bike aka 250..........wait, they'll mod that too.......never mind

 

[RayWebb1]

I am totally with you on that. If you want a faster bike buy a bigger one. I won't be fitting a big bore kit or changing the exhaust etc.etc. I like the bike as it is. The spark arrester question was out of curiosity and whether it is really necessary on a UK bike.

 

[SneakyDingo]

I mean.... can you take a fire steel and start a fire easily with kindling you find anywhere nearby, at any time of the year? Additionally, is climate change trending towards drier weather?

I don't think it's necessary on most of the bikes, but we did have one guy set Oregon ablaze by trying to burn his TP that one time so I'm going with "people are stupid, engineers are trying to safeguard against the stupidity."

 

[oldskool]

I mean.... can you take a fire steel and start a fire easily with kindling you find anywhere nearby, at any time of the year? Additionally, is climate change trending towards drier weather?

I don't think it's necessary on most of the bikes, but we did have one guy set Oregon ablaze by trying to burn his TP that one time so I'm going with "people are stupid, engineers are trying to safeguard against the stupidity."

It may or may not actually do much to prevent fires,I don't know. That doesn't really matter to the forest ranger that is tasked with being the law of the woods. The ticket for being offroad and not having one or one modified is not cheap. Benifit vs risk we make decisions everyday based on our priorities.

 

[SneakyDingo]

It may or may not actually do much to prevent fires,I don't know. That doesn't really matter to the forest ranger that is tasked with being the law of the woods. The ticket for being offroad and not having one or one modified is not cheap. Benifit vs risk we make decisions everyday based on our priorities.

I can understand why Forest Ranger sir would be against removing it (from Australia, have been in a bushfire before). But if OP answers "yes, dry ignites are possible" then I'd be pretty against removing it. Less maintenance isn't a good reason to me, it's 6 bolts and a scrubbing brush what... once every 4k miles? That's like being against every other oil change.