The time came to replace the H section in my original exhaust system. Small holes appearing in the pipe, blowing out just where internal stops welded to the header ends go in.
No problem, I will order up a new one from Gutsibits.
First problem, none in stock. Have to wait for 2 months for it to come from Italy.
All looks very nice initially. I then remove the original one and find the ends that go into the Lafranconis to be a couple of inches shorter on the new one.
Undeterred and not wanting another 2 month delay in riding season I press on. The H section fits onto the headers fine. How ever the silencers just wont fit . I measure the diameter of the new one, 42.47mm. The old one 41.59mm. I then spent several hours with an abrasive flap wheel reducing these so my silencers fit over correctly and line up with the frame holes.
A phone call to Gutsibits after the weekend follows explaining situation. They were apologetic for the hassle and said they would contact their manufacturers to ensure that future parts are to correct measurements. However NO offer of compensation as the part has been fitted following adjustments.
At least I will be able to ride in what remains of summer. However do I try to get my old section repaired or do I order another one from Gutsibits and measure it very carefully or any other solution?
I post this so that members become aware of the issue and dont get caught out thinking that these remanufactured parts are as per original fitment.
You could get an engineering company to make up a pattern one, either in stainless steel or ordinary.
For what its worth, apart from adding some rigidity you probably don’t need a cross over pipe at all. I think that with higher performance models it has a benefit but not the tourers.
Ive run my SP1000 without one for decades.
Andrew
Both Keihan and Armours produce stainless balance pipes for the older big twins. They usually fit fine.
Hi A valuable lesson here i think! as you quite rightly say NEVER ASSUME that a replacement part is exactly the same as the original! Always check and possibly measure first! and if in doubt dont even fit it! and NEVER NEVER NEVER modify it in any way cause if you do you instantly remove any chance whatsoever of getting a refund or replacement!.
thanks for posting as a timely reminder and warning to us all!!.
Thanks for the replies, I’ll be giving Keihan and Armours a call. Need to find out whether their part will fit the Lafranconi silencer or only their silencer. If not then I’m thinking of getting my local custom bike engineer to sort some connecting pipes in stainless. I may even try the balance pipe delete. It would make mixture checking a lot easier although the back pressure will get higher as each cylinder will see only one silencer.?
At least if you get a custom one made you will know its gonna fit your bike! plus you get to choose the specs and can increase/decrease the balance tube pipe diameter to suit what you want to achieve!! probably no more expensive than buying a branded one either!.
might be good to post your solution/outcome and costs as a guide to others!
best of luck with it!
stay safe!
Steve
Many replacement parts don’t fit, cables are a big problem for me on my Sport and V10, cheaper in the long run to have them made to the correct size. Beware of ordering direct from Italy Mistral charged me two lots of vat and just gave me abuse when I tried to get it sorted, thx to Fed Ex for sorting it out. Guy at Gutsibits always does his best but he can’t know exact sizes for everything.
Update, I have been to my ever helpful custom engineer. We are going to see about making 2 stainless connectors to link headers to the Lafranconis. He’s keen to do this as he reckons the sound from a non linked twin exhaust is better. He’s a Vintage Harley fan, I’ll take his word for it. The Convert isnt a performance bike so I won’t miss a few horses. Slightly off topic, a Mk1 Lemans Barn find off road at least 20 years running and sounding free from mechanical engine noises,gearbox unknown, dead master cylinders, rusty frame, oxidised red paint and really in need of extensive mechanical and cosmetic attention. Stucci type seat. What price is reasonable for such a machine?
I have been running with no link pipe for years, if you can get your hands on two lengths of stainless tube, I think it’s 38mm ? You can get the ends enlarged to slip over header pipes ( I used a local car exhaust fabricator ) the tail ends you feed into exhaust, you may need packing spacers (eBay) depending on inlet size of the exhaust siencer
Thanks for the help ful advice and pictures. Does the slight curve on the original at the H section matter? Or can you just run a straight pipe header to silencer.
Hi, I can only say on mine the tubes are totally straight, they came from the food industry,
I am not using standard silencers
Hi, if you are going to the trouble of making up the connector pipes why not make up and weld in the cross pipe? I guess there must have been a good reason for Moto Guzzi to include it in the first place. I had to get an H section made up for my Convert, we used stainless steel and had a very poor original to use as a pattern. Maybe you can do the same. Cheers Phil