1971 750 Hi-Rider Restoration Question

My friend, a very long-term Nortoneer with a kick-ass '75 Commando, is finishing up a complete restoration on a client's '71 750. The client wanted everything stock...original hi-rider bars (ugh!), original dual Amals, points, K-81's, ect., etc. The bike is 95% finished and we've been out the last couple of weekends together doing road tests. Cosmetically, the bike is gorgeous...bare frame-up restoration, everything polished to mirror-like quality.

The issue is: My friend has convinced the client to use straight header pipes without peashooters because the exhaust note is...well....LOUD...and my objections aren't carrying any weight. Last minute problems include:

1. Poor idle...informed him about cleaning out the idle circut w/ the #78-sized drill bit, sychcronizing the carbs, sent him the AMR & OldBrits info on Amal set-up (We both run Mikuni TM34's), etc.
2. Popping/backfire on deceleration....looking into lean condition.

My main question concerns the choice to eliminate the peashooters. Any expert opinions regarding running straight pipes vs. mufflers would be greatly appreciated...and ones I could pass on to him to convince him to think otherwise.

[video]http://www.youtube.com/watch?v=KjKUKhHQLHg&feature=player_embedded[/video]

The old guys always told me I'd burn / warp my exhaust valves. Old gas station tale?

Both 1 and 2 can be the same problem - clogged idle jets.

chip
first things first. it is probably trouble in the carbs with plugged idle circuits. is it billy working on it? if so he can call me. second running straight pipes is just plane STUPID and asking for trouble along with giving us ALL a bad name plus does NOTHING good for performance

Have them both (builder and customer) watch this: http://www.southparkstudios.com/full-ep ... the-f-word repeat as needed until they get the picture...

Concours us Canadians be blinded. Love South Park.

I had a muffler bracket break right before 1000 mile trip to Ohio so just ran 2-1 open pipe which was annoying loud but more annoying very weal performance and response to toddle around camp or slow traffic and did not make the power mid range and above it did with a peashooter on or megaphone with butt plate. I tried a bolt with a washer in the pipe like the thumb screw in video to find it did help a little bit but open drag pipes sucked on a Combat. On the other hand my P!! had open drag pipes and it had goof idle in 4th gear torque and no issue to response as tire spun if throttle opened to fast while going too slow. Don't know why the difference.

bill said:

chip
first things first. it is probably trouble in the carbs with plugged idle circuits. is it billy working on it? if so he can call me. second running straight pipes is just plane STUPID and asking for trouble along with giving us ALL a bad name plus does NOTHING good for performance

Click to expand...

I SO agree with Bill here !!! Now as far as it being a "Hi-Rider" ... I luv that style, 8) and me thinks we need more of em out there !!!

The best compelling reason I can think of is that the header pipes are unsupported, i.e. no connecting muffler suspended, so the damn pipes will wobble up n down with the engine rocking motion. Just watch that happen and you soon realise all the stress is at the exhaust port joint where it is going to fatigue and fail.

Next compelling reason is it supposed to be a complete restoration? Its not some caveman's Harley.

Mick

There's plenty of factory pure HyRyders all over the world, accepted only because they are genuine Norton issue but hardly any caveman chopper Nortons that offend everyone for a treat. I say extend them open pipes out above the tail light to get the low down torque back in deep base notes. I was given a nice HyRyder ape hanger bars I only used on Peel mock up at Empire rally to test reactions to superficial appearances. Available for postage to ship.

the name APEHANGERS is an appropriate name for that style of bar's. the loud pipes, apehanger bars and NO BRAKES choppers all fit with the mentality of an APE and an IQ well below room temperature. IMHO the loud pipes has done more damage to our sport than most anything else. myrtle beach has tried to run the bikes out and daytona has resorted to blocking off streets all because of IDIOTS with loud pipes.