weld in a washer to restrict the new pipes?

[snowbeard]

if you've seen any of my shenanigans yet, I have changed the pipes on my bike to some harley shorties, and this has made me run lean. I don't want to hurt my engine, and I would prefer this exhaust to be "self contained" in that I still have the OEM and can put that on at anytime and fix my problem, so I don't really want to rejet or mess with my needles.

so how about welding in a washer in the end of this pipe, the rusty end is inside of the new cans, but should restrict all four of the cylinders. then the cans would just be there to direct the exhaust.

http://img234.imageshack.us/img234/2682/cutmj4.jpg

is this ever done? think it would work? I expect it would take a few tries to get it right, but better than dinking around with having to pull those d@mn carbs!!!

[Tarbash 27]

yes ive done it, get a washer that has an opening of at least an inch and it should run ok. any more than that it will be to lean, any less is too much backpressure

[Planecrazy]

It might take more than a few tries to get it just right, but why not? I say "go for it!"

Regards,

[Road_Clam]

if you've seen any of my shenanigans yet, I have changed the pipes on my bike to some harley shorties, and this has made me run lean. I don't want to hurt my engine, and I would prefer this exhaust to be "self contained" in that I still have the OEM and can put that on at anytime and fix my problem, so I don't really want to rejet or mess with my needles.

so how about welding in a washer in the end of this pipe, the rusty end is inside of the new cans, but should restrict all four of the cylinders. then the cans would just be there to direct the exhaust.

http://img234.imageshack.us/img234/2682/cutmj4.jpg

is this ever done? think it would work? I expect it would take a few tries to get it right, but better than dinking around with having to pull those d@mn carbs!!!

Thats an old skool trick for gaining some needed backpressure in straight "drag" style pipes. You weld a 1" OD 5/8" ID washer to a 1/4-20 bolt, and bolt it up inside your exhauset to create some backpressure.

[Tnutz]

hey thats not a bad trick, i wanna do a straight pipe on my GPZ 1100, just be able to pull of the yosh pipe, and slid on a straight pipe onto the header, but i was scared i would lean the EFI out to bad...

[snowbeard]

well its good y'all dint say abolutely not!! I may have to retry this as I didn't have much idea what to do for size. I never claimed to be a welder, so take it easy on me

this is my second welding attempt, the first being having to fix my wife's candelabra after I knocked it over...

oh, and I moved away from the gas can before I started...







this is all shoved up into the pipes and doesn't show, so at least maybe it'll be easier to knock off if it doesn't work, but it is about the same size as the opening of the originals...

we'll see tomorrow how it turns out, felt bad enough grinding all night, let alone blowing up a motorcycle!!

[Tarbash 27]

Well i took a piece of fence pipe and cut it about 8 inches long. than i cut one side to make it like a slash cut. so it looks like slash cut pipes. i than took a steering stem cup off a bicycle and welded it in. the inner diameter is 1 1/8 inch. than i slipped the fence pipe onto my exhaust and clamped it on. I tried washers smaller than 1 1/8 and it was a significant loss in power. It had way to much backpressure. You can kinda see the exhaust tip in my picture if you click on it.

The hole in your exhaust in my opinion seems too small and will have too much backpressure.

[Dave8338]

Crank up the amperage (60-65), on your welder and go with a 6013 or 7014 rod. You'll get better penetration on the weld...also aim the majority of the of your heat (rod) at the washer due to the thickness of the metal. My pops is a retired industrial arts instructor, had all this stuff pounded down my throat when I was too young to even care. Thanks dad!

Dave

[snowbeard]

thanks for the advice, mine is a wire feed 110V box. it has the gas hook up but I don't have the gas. I think I could do much better with a rod and a flame, or even just something I can see the actual tip of... I also found at the very end of the job that my feeder was slipping also, making the wire not feed consistently, so I think that's part of it too... I did aim more for the washer, as I burnt a hole in the rusty pipe in the beginning, but only that once.

I rode to work today and it had good power throughout as far as I could tell, the sound is just a bit less, which is also good. I'll take it out at lunch and do a few plug readings to finalize my decision.

turns out that isn't the only hole, there's a 1/4" hole in the side of the inner baffle pipe that I welded the washer on. that with the lack of a solid weld all the way around makes me think that I'm only barely using that washer hole for much...

looks like you're running pods on yours Tarbash? did you rejet also? is that the steering cup on the outside or is it in the fencepipe? that was what I'm trying to avoid, I've still got the stock jets and would like to keep it that way for reversibility (putting the old exhaust back on if I ever want to)

is that the steering cup on the outside or is it in the fencepipe? that might also be part of it, I've got two holes to your one, mine should each be half the size, no? (I have no claim to understanding some of these things...)

[Tarbash 27]

i welded the cup inside the fence pipe so its hidden. I rejetted for the pods when i had the stock exhaust. so going from stock exhaust to what i have now didnt effect it that much.

[snowbeard]

well the chop showed still lean even with that small of a hole. tried welding on yet another smaller one and that still chopped lean, and it felt a bit strangled. so i'm going to try the jets i have in my 850 carbs, but one needle was cracked and broke off the threads

i'll try to get a new one somewhere sooner than later, just to find out if this actually works, 110 is what it had, 115 is what i have extra. i'll have to at least go back to the first washer.

thanks for the advices!!