Simplex Stretch

[Ricks]

Cleans it up a bit . Will you be covering the coil, Rick ?

Pete .

I am considering it. I don't want something that looks too bulky though.

[kartjockey]

Nice J O B!

[ndian22]

Really looking good Rick, with the factory cover off, and kick start it looks like a "proper" vintage cycle engine. I'm impressed with what you've got going on & most are already familiar with how dependable & great these Honda's really are! Rick C.

[Ricks]

While waiting on tube bends to build the exhaust, I made some flanges for the exhaust and the air filter adapter.  I am going to mount the stock simplex air filter down low just like original.  Being that the carb is mounted high, I am using a 90 degree bend to lower it and turn it to face outwards.  I also cut a piece of 4" OD stainless tube to the proper length, and will make end caps.  Being a 4 stroke, I was thinking of stuffing some stainless mesh into the canister to act as a muffler.  Is this a viable idea to help quiet the motor, or will I just be chocking it off?

[pd]

Rick ,

I think the stainless mesh might be alright if you leave access to change it .
I have removable 'caps' on my muffler and Course steel wool inside . It does a decent job of muffling the tone , but it also packs and becomes more dense with contaminants . That's on the OEM 2 stroke . I would think a four stroke would / should burn cleaner .

On the other side , permanent baffle plates would likely last longer than you'd care about .

Tuning the muffler will be the biggest challenge .

Pete .

[Ricks]

Rick ,

I think the stainless mesh might be alright if you leave access to change it .
I have removable 'caps' on my muffler and Course steel wool inside . It does a decent job of muffling the tone , but it also packs and becomes more dense with contaminants . That's on the OEM 2 stroke . I would think a four stroke would / should burn cleaner .

On the other side , permanent baffle plates would likely last longer than you'd care about .

Tuning the muffler will be the biggest challenge .

Pete .

Pete, why did you put steel wool in yours?   I thought the stock mufflers are just empty cans? 

I will not have access inside my can when it is done, but I thought either stainless or copper would last a long time.  I think these 4 stroke motors burn very clean, so I am not too worried about contaminants.

I always thought 4 stroke motors were not very fussy when it came to mufflers, but 2 stroke motors could be tuned through the size of the pipe/resonator?

[Ricks]

To cap the ends of the canister,  I cut some discs out of scrape 16 gauge I had laying around.  I then domed them using a planishing hammer I built last winter.  Check out the results and the hammer.

[pd]

From all I've read , the stock mufflers were / are empty . They might have some pipe extending into the muffler can , but , I wouldn't think much .
I used steel wool to tune down the exhaust tone , which was very harsh / raspy . I have 2 short pipes , about the same length as on the shorty OEM mufflers . If I'm not mistaken , the OEM shorty has only a single outlet pipe .

The longer outlet pipe has a bit more restriction than the shorter and therefore a bit quieter .

In my previous post , I meant tuning for tone / sound rather than performance .
In the small 4 stroke motors , almost anything , within reason , can be hung off the exhaust port . I suppose you could 'tune' for better performance using anti reversion technology . I'm not sure any gain would be realized , but , it wouldn't hurt , either . Basically , extending the header pipe into your muffler can should be effective .

Here's an article that should help with your exhaust system :
http://blog.jpcycles.com/2010/07/will-i-need-to-rejet-when-i-change-my-pipes/

The author is talking about Harley motorcycles , but you'll get the idea .

I'd like to build an expansion chamber for my OEM 2 stroke just to see what gains could be had . But , that would be hard to do and still retain a factory appearance .

Pete .

[Ricks]

Pete, you are correct, the shorty is a single pipe.  I don't think they are loud at all.  In my estimation, the 2 long pipes are much deeper and throaty sounding. 

When I built the Truck with the clone motor, I did not put a muffler on it right away.  That engine, with a 30" pipe on it, was so loud it was obnoxious!  I welded a simple mower muffler on it and it was so much nicer to my ears.

[kartjockey]

I would put some coarse mesh in the canister and not look back.  A 4 stroke will never care.  Thats my opinion. 

I should be hanging out in Speonk with you!.  Your Stretch is looking great!  I need to go fire up one of my bikes up!!!!

[Ricks]

I would put some coarse mesh in the canister and not look back.  A 4 stroke will never care.  Thats my opinion. 

I should be hanging out in Speonk with you!.  Your Stretch is looking great!  I need to go fire up one of my bikes up!!!!

Thanks Tom. 

I spent a few hours today learning a tiny bit about Tig welding.  I made some really ugly welds, and a couple that were nice.  Reminds me of my younger days, when I gas welded in a muffler shop.  Some more practice over the next week or two and I should be  able to weld the exhaust together, without making it a complete mess.

[Ricks]

Got the exhaust mocked up.  Has good clearance all around, even the side kick stand used on these earlier models.  I also got it tucked up high, right under the kickstart shaft.  Maybe by next week I can find the time to weld it up.

Only 4 months to Portland!  I hope I can at least get it ridable for the meet.

[pd]

That looks like it might just work , Rick .

Pete .

[ndian22]

Stretch is looking great. I understand building in your spare time is a slow go but often the ideas flow more freely in between work sessions & things just turn out better as a result. You've got this project rolling down hill with the right momentum already...objects in motion tend to continue in motion & you have this one well in hand.  Rick C.

[Sonrisers]

Looks good Rick, when we built the exhaust for my original motor we had the tail pipes run along the frame....looked good, but wasn't enough clearance. looks like you done it right.