750 GT Headers, Are they all different?

H

Hunter

Junior member
Location
Raleigh, NC USA
Hello Laverda people,
On my 69 American eagle I am using the old nasty header pipes. I bought new ones from Wolfgang years ago but they didn't fit, they turn in too close to the cases and the end of the header is about  2 1/2 inches to high to meet the muffler. Also the collar welded onto the pipe at the cylinder head seems out of place as the securing collar bottoms out onto the head without really sealing up.  Long story short they went back, he put them on an Eagle there and they fit so he mailed them back. But they don't fit MY bike.
So what gives? Are there multitudes of head/frame/muffler combo?
Thanks in advance.
Hunter
 
Pipes are pipes for a 2 Cly Breganzie or for any motorcycle for that matter, whatever, it's either 2 into 2 or 2 into 1 for a 2 Cyl - The biggest problem is choosing the right Main Jets so you don't lean out the mixture and melt the pistons.
 
Hunter said:
Hello Laverda people,
On my 69 American eagle I am using the old nasty header pipes. I bought new ones from Wolfgang years ago but they didn't fit, they turn in too close to the cases and the end of the header is about  2 1/2 inches to high to meet the muffler. Also the collar welded onto the pipe at the cylinder head seems out of place as the securing collar bottoms out onto the head without really sealing up.  Long story short they went back, he put them on an Eagle there and they fit so he mailed them back. But they don't fit MY bike.
So what gives? Are there multitudes of head/frame/muffler combo?
Thanks in advance.
Hunter
Click to expand...

Check if the head hasn't been modified in some way or another.  All twin pipes should fit all twin heads, not aware of any changes along the way.

Got a pic of the headers that fit?

piet
 
I'm not aware of any difference in pipes but wouldn't be very surprised if there were some variations in very early machines.
Would need to check on some of mine but unfortunately don't have them to hand.
What's the engine n? of your machine?
Paul
 
Paul Marx said:
I'm not aware of any difference in pipes but wouldn't be very surprised if there were some variations in very early machines.
Would need to check on some of mine but unfortunately don't have them to hand.
What's the engine n? of your machine?
Paul
Click to expand...

Paul,
My engine is 1240. Interesting to know that all stock 750 pipes are the same.
Here is a photo of another Eagle with the right pipe:
example2.jpg


and here are some photos of the pipes I bought for my bike. It was not complete at the time. Notice how it is right up against the engine.
MyLaverda1.jpg

MyLaverda2.jpg


And just for fun here is what I started out with.
Eagle2.jpg
 
Piet didn?t say that all SF headers are the same, but that they will all fit the head.
Check any pics of the different models and you will see that SF1-3 header sweep and length is vastly different to earlier models.
Some models had the connecting pipe just in front of the engine.
Do you have the proper thickness gaskets in the head?
Do your mufflers mount in original position?
 
Our 69 GT and S have very different header pipes.  GT is mid 1900's, S in low 2000's.  Both have original exhausts on them.
Shape of our GT pipes is not as round as yours - if that makes sense.
Muffler end of header pipe ends roughly in same place tho, as they both use the same mufflers and mounting system.

A quick peruse thru photos of 750's will show many variations, especially with remanufactured pipes. If you check out Andy W's online site, you will find he has several different pipe sets, all with photos. If you have his 750 'parts' book, then there are quite a few photos showing different systems on bikes.

The photos of the new pipes appear to be more S than GT in shape. but without the bridging/balance pipe up near the exhaust ports.  The new pipes don't seem long enough, from my photos of our bikes they should end further back (towards rear of bike).
 
Tippie said:
Piet didn?t say that all SF headers are the same, but that they will all fit the head.
Check any pics of the different models and you will see that SF1-3 header sweep and length is vastly different to earlier models.
Some models had the connecting pipe just in front of the engine.
Do you have the proper thickness gaskets in the head?
Do your mufflers mount in original position?
Click to expand...

My apologies, I see what Piet wrote now that I read it again. My mufflers are correct for a GT and work fine with my original pipes. The original pipes fit the head just fine and are tight with the mounting collar about 2mm away from the head at the mounting studs.
Looks like the new pipes I have are just wrong for my bike then.
Thanks to you all for the help. I will order up some correct pipes!
Hunter
 
The actual bend of the "new" headers seems to be close to a "S" type system, but without the connecting tube in front of the head.  Not sure about the length, have a S in the workshop at the moment, can check next week.

GT and S silencers are identical.

piet

 
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