Why won't this exhaust header pipe fit?! Ugh! - Seca 550

Finally, I'm at the end of restoring an original exhaust onto my 82 Seca. But no, for some reason, the header pipe #4 won't fit!! This pipes came off a Maxim 550. I thought the pipes were the same?? I got the other ones on. But no, #4 Maxim pipe appears to have a more obtuse angle bend where it meets the collector. I have a Seca pipe for 4 that indeed will fit fine in there, but its got a good dent in it.

So, am I crazy, or, is it possible to have a muffler shop slightly bend this pipe for me? I have no idea if a chromed pipe would bend OK.

BTW, I did try to lower the collector somewhat, but that didn't help. If for some reason I'm suppose to attach all the header pipes, and then insert them all into the collector at the same time before bolting that onto the frame, let me know. It's my first time messing with this.

Thanks.

 

1, 2, 3, 4.

11, 21, 31, 41 !

No.4 = P/N 4G0-146(41)-00-00 PIPE, EXHAUST 4

One, forty-six, FORTY ONE !

Check the P/N ... first.

 

I did check the serial numbers. They are there on my set of (mostly dented) Seca pipes, but on the Maxim pipes, it only says "G1" "G2", etc. So, I'm assuming I'm ok with the G4 in the 4th spot, but it ain't fitting!

 

I didn't think a Mxim exhaust header would fit a seca, for the exact reason you've described

 

Re: Why won't this exhaust header pipe fit?! Ugh! - Seca 55

I also thought they should fit (all the XJ 4-cyls use the same exhaust gasket), but you will probably need to replace the entire exhaust system (i.e., complete Maxim unit onto a Seca) plus figure out any collector/muffler mounting differences. I'm guessing that the Maxim/Seca collector boxes are different so that the header pipes are not a direct fit.
You might get a muffler shop to bend it but you will get no guarantees as to how it might affect the chrome.

 

My understanding was that the headers and collector are the same between these bikes, but the mufflers are different. I mean, with 3 of the pipes on, it seems odd that only the 4th is being annoying.

 

The pipes and collector box for the 550 Maxim and 550 Seca should be identical.

They should also say "Yamaha 4G0-1" -2, etc., on the pipes. If they don't say "4G0" they're probably not 550 pipes.

The exhaust system on my '81 is a conglomeration of Maxim and Seca parts and it fits fine.

I suspect you've got a "ringer" there.

 

If the Pipe you have WAS on there and you can't get it to go on, ... now; it might be a matter of ...

Upper & Lower simultaneous connecting.
(If its the right part) ... 'cause if it ain't ... yer gunna need Jesus to miracle it on there.

The right part will fit.
Wrong part won't.
Oh, ... you can get "Close". But, close only counts in Horse-shoes and Nuclear weapons.

"Simul-fitting" is, ... TOP and BOTTOM mated in one move. / } < One move.

Non-fitting might be off by as little as a "Pew-Bic-Hare". That's the worst case scenario.
It'll make you pull at your hair tryin' every which way to make it go.
If it gets to that , ... give up.
Or else they'll all be callin' you: "Baldie"!

 

Apologies Rick. I guess I didn't explain it so well. Bike came with a 4-ino-1. I got rid of it. I bought 2 sets of pipes: 1 from another seca 550, one from a Maxim. The Maxim pipes were in better shape. However, it's the 4th pipe that is giving me the grief. These "Maxim" pipes only have G-1, G-2 etc stamped into them. There is no longer part number as indicated by some previous posts. So, I'm not sure what to make of it all.

I'm going to my local car shop today with both pipes (one fits, but is dented) and the one that does just to see if they can bend it the 1/4"-1/2". Can hurt to try.

 

The pipes are dual-walled; attempting to bend one may fracture the inner pipe.

Are you SURE the Maxim pipes aren't from a 750?

 

Though even if the wall splits, wouldn't the worst case scenario be your pipes will blue if you ride hard and possibly rust inside over the course of a VERY long time? (Just wondering, checking personal knowledge.)

 

From Googling the Yam P/N:

http://www.edssurplusforsale.net/servle ... cle/Detail

http://www.boatpartguys.com/ocart/4G0-1 ... 7&limit=75

http://www.powersportsplus.com/parts/se ... parts.html
•• P/N's Match? Radian?

I think you need to find the RIGHT Part.

Although I did see an unorthodox exhaust repair job, one time.

The sketch is this:

The Lower "Neck" that inserts into the Collector was "Cut-back" leaving just a shoulder at the Bottom-end.
A short length of "Flex-Hose" welded-on to what became just a collar.
2-Inches of Pipe fitted --> OVER the Flex Hose and welded tight.
The Pipe needed to be "Expanded" to have the I-D fit the O-D of the Flex.
A New Inlet welded on the Collector.
After "Mucho-voodoo" ... the connection to the Collector hooked-up and secured with a Small Universal Clamp.

Cue Banjo player:
♫♪♪ Duh-dah -- dum-dah -- dim-dam -- ding-dah-dum ♩ ♫♫ ♭

 

Yeah, and a guy I went to high school with had BSA mufflers very neatly fitted (using the aforementioned flex-pipe) to his POS '53 Jaguar.

Which has little to do with the fact that OP has pipes that are decidedly NOT 550 pipes. If they don't say "Yamaha 4G0-" 1~4 then they didn't come off a 550, Seca OR Max. And he's trying to bring the bike back to stock. You're correct in that he needs to find the right part.

5G2 was the 750 Seca model prefix. "G2" is not "4G0" so they're not the right pipes. I'm admittedly guessing at their origin; all I know for 100% sure is they didn't come off a USA-market 550, of either flavor.

My advice would be to find the correct pipes rather than risk damaging something. You'll know they're correct if they say "Yamaha 4G0-" on them.

***LAST MINUTE EDIT*** so I went and looked at ALL of my "spare" 550 pipes. (They all say 4G0.) BUT: I have no less then THREE #4 pipes you could pick from-- none of which are perfect. You can pick between 1 big but largely hidden dent; lots of (4~5) little dents; or no dents but lightly rusted, mainly on the backside. Price negotiable but cheap.

Might also want to get ahold of Hogfiddles and see what he has.

I'd kill for a pristine #2 myself.

 

Thank you both Rick and Fitz for you input. What weird pipe... I wonder what it truly goes on! Once I had written it off, I had the local mechanic try to bend it a bit. No luck. I went to the metal shop at the University I work at - they said they didn't really have the equipment to do it. Then, I went to Midas because they were nearby. They said the equipment they have couldn't accommodate such a small pipe. So finally, I said screw it, and ordered one for $42 that Rick had identified. I need a few screws and such from Powersport Plus anyways.

I'm sure learning a lot by fixing on these things....

 

I have two sets of useable but nowhere near pristine, pipes from two 550 Maxims that I have parted. I know you said you already ordered one, but in the event you need other 550 parts, PM me.....I have a lot.

Dave Fox