exhaust helpi

yesterday a friend of my girlfriend hit my bike with her car and destroyed one of my mufflers.
I went outside and picked up my bike some how the only damage was to the muffler, a bent front brake lever and a scraped crash bar. Or so i thought.
Within 15 seconds or so i had a stream of gas running down my driveway.
I figured the tank now had a hole in it. No such luck some how carb 3 had cracked through the body from mount screw to mount screw and card four had been ripped off the rack leaving some of the aluminum still bolted to the rack rails. And the bowl split wide open.

So now to the point of my long explaination of what happened:
Your guys help!
I need to know a few things.

What size is the exhaust tubing after the cross over pipe?

And can some please give me the link to the thread where the guy succesfully converted to two carbs?

Yes I have my heart set on changing to the two carb system and aftermarket mufflers

 

Don't quote me but i believe The pipe is 1.25" after the collector.
Most available slip on mufflers will work.

No help on the carbs unless that was orangeandblack on the tiger stripe bike.
Fair warning! It was found that the gas softened the pvc tubing used to make the intake on his bike.

~ Ghost

 

Yes that is the one. I had the measurments for a machine shop to make a custom intake manifold out of aluminum. Gave them those and then a week later go to talk to them about making it and they are closed down

 

Why do you want to try to convert to 2 carbs? Get another set of 4 carbs and rebuild them if set up right you wont have to mess with them. My opionion is you will be messing with carbs and unless you are a machinist or have friends you will need to fab an intake, and obtain carbs possible Amal carbs this will invovle money outlay and bike may not have as much power. You could try a single 2 barrel or holley 4 barrel in the 390cfm range . Again what reward would it be? Sucks that your bike was damaged hope she pays for parts to repair.

 

It depends on a couple things....

1. The muffler/crossover pipe is a single piece into on each side that slips together in the middle.

2. Where do you plan to cut? there is a bit of a taper. Most people who try to do a replacement or repair, cut at the end of the muffler itself and Rebels right ther. You can see that's just shy of 50mm OD

3. Many have also just gone cut the pipe just after the crossover, and cobbed a fitting together to put other mufflers on. You can see that's just shy of 39mm, BUT you'' need to grind down the existing weld in order to slip things on.....unless you slip inside-----which I wouldn't really recommend. These engines and exhausts are very free-blowing, but I don't see any need to try and restrict it even a tiny bit.

As far as carbs, I recommend pull the rack off and replace the broken parts. While it's off, check the whole rack to make sure nothing else got broken. Heck, while its off, go through the whole thing and make sure it's nice and clean again.



Hope that helps---

Dave

 

My Mack 4 into 2 exhaust does not have a collector or cross over pipe , this exhaust is an alternative to the stock exhaust. ( not cheap though)

 

My Bad. I was in 750 mode.

~Ghost

 

Finding a good set of carbs for my other 650 was a task and cost alot more then the two carb swap. Total rebuild, cost of carbs, and new hardware around $650
I would like to leave the cross over pipe just replace the mufflers with some aftermarket mufflers

 

I am a mechanic by trade and rebuild old bikes as a hobby. If it came to needing some amal carbs ive got that covered.
I have 3 sets at the shop right now
Im going to get the intake manifolds made up and play around with some diffrent carb setups as work lets me.
Will keep you all updated as i make progress

 

Where is the cost of 650$ ? you can find used carbs for our bikes around 100$ or less on eBay , I bought a set for 65$ ( I needed a #1 carb P.O. crushed throat ) , Chacal has the Overhaul kits as needed I.E. seals ,gaskets and jets as required I went hog wild on my carbs put allen head drain screws in ,and stainless hardware I spent less than 200$ . I just fail to see what benefit you will obtain other than to say you did it. What you might think about buy another rack use the parts that are still useable off the damaged rack , this way you minimize spending. A few years ago I had an 82 Virago 750 ,and was on the Virago forum , a few folks tried to convert to single carbs with mixed results ( IE lots of problems with intake set up) I had issues getting bike to run period had sat since 84 with 4500 miles ... after rebuilding carbs and putting CORRECT jets ( kits had wrong jets) in and new air filter bike ran great. Please don't take what I rambled on about as a slight against you or your abilities , I don't want to insult you in anyway, I just wanted to help you avoid more work than might not need to be done. Good luck no matter which way you go with this.

 

Even when I do total rebuilds for people, including all the labor and a boatload of new parts from Len, it STILL doesn't come to that. (unless I have to buy multiple rack to keep pulling parts off of, but even then,It's cheaper to buy a different rebuildable rack and do a total rebuild

Dave fox

 

I had it replace ALL hardware, two diaphram, fix a broken float post, replace a damaged fuel bowl, and replace jets (previous owner had drilled them out).
I over payed for the carbs almost $220 with shipping.
Yes it cost alot for it but i was really wanting to get this bike going.

 

I have the carbs and know how to do this. I think i even have a carb off a riding lawn mower that i think i could make work and one day i might get the bug to try.
For all the purists on here the bike was chopped up and "customised" by one of the previous owners.
That was a mess that took some time to get it safe to ride.

 

Did you ever make a intake manifold if so how did it work out and got any pictures??