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[jefrs]

You have an after market indian exhaust system. Could be iffy but if it ain't bust... Less restrictive is good but straight through is not, the motor needs back pressure from baffles to provide low-end and mid-range torque. It's never going to be a fast bike but it does have torque, so tune for the torque.



Kick starting on a fully open throttle is going to hit your foot but it's no DBD34 so it's not going to throw you over the hedge. Kick starting a Bullet should be a lazy prod, there is a knack to it (as on any bike, individualistic), opening the throttle just-so to catch it.



Silicone bath sealant, available in several colours. Silicone rubber is high temperature, as used on soldering iron leads, it doesn't burn if you put the soldering iron on it (~800°F). That's for the push-fit pipe but the clamped on pipe doesn't need goo, it needs copper gaskets, maybe two, RE p/n 582638 (582638/A) - the "correct part" cement ring 510804 is practically useless, it disintegrates. A 2008 should be clamp, do use the torque wrench.



Popping and spluttering on the over-run is 'reversion', the bane of fuel injectors; unburnt fuel going down the exhaust and burning there with cold air, it's not really an explosion but rapidly expanding gases. The cure (partial) is to either enrich or weaken the mix. With an injector we have an option to shut the fuel off completely at zero throttle until the revs drop to near idle again (this can be lumpy). With a carburettor the only real option is to enrich the idle mix (closed throttle), it wastes fuel but doesn't go ka-pow down the exhaust so much. Otoh you need the idle mix right to start the bike and idle it, a little rich is usually just right.

[Tim NZ]

What a load of misplaced waffle.


The Electra X achieved optimsed low-end torque (Breathing) via a high velocity exhaust stream: small dia Inner header pipe. "back pressure" claims with-out knowledge of cam timings and lobe centers is meaningless waffle. And the std Electa X cam timings are NOT conducive to higher rpm breathing ability.


Optimised exhaust tuning is SFA to do with 'back-pressure' (misunderstood modern day myth) but more to do with ex gas velocity, pipe capacity, and time.


IF the Electra X still has the exhaust 'hot-tube' stuffed up its bum, it will be more inclined to 'Pop' on the over run. Cut it out...


With the Std Cast Iron barreled bikes with the same 'hot-tube' stuffed up the back of the header pipe, excessive enriching of the pilot mixture (or a leaky choke?) leads to chronic Bluing of the header pipe in the location of the 'Hot-tube' (Look at the header under the foot peg)

[Frank]

I can't remember how I inadvertently got rid of the popping on the over run, perhaps it was the tightening of the PAV pipe union on the cylinder head exhaust port, a shame really because it lost a bit of character.

[sofiaspin]

My experience, by trial and error and working through the various options (baffle in or baffle out, air screw settings, bellmouth on or off, small or large) concur with Tim's comments. The proof in the pudding is if the ignition and fuelling work perfectly from start to 80mph without stuttering or popping, then it must be close to being correct for the set-up (again to recap in my case Mk 1 Amal conc, open 50s pipe from hosts), airbox etc removed). When I removed the bellmouth completely, the bike was gasping for fuel at higher speeds. On my cast iron barrel bike the same set up has airscrew set at just under one turn out, no blueing of pipe, perfect running, but baffle is in - only to cure excessive noise. With baffle out it is leaned slightly but running is not affected). My Velo Venom Clubman had a mega exhaust, take out the baffle and it would be a good .3 of a second before the bike reacted and then it was off like a shot.

[PeteF]

There is so much bo**ocks talked about back pressure in 4 stroke exhausts.
The truth is you want as close to nil back pressure as possible without compromising exhaust gas velocity.
Making a truly efficient exhaust system for an RE with the parts generally available is not easy. Probably the best you can do is start with a straight through system and then fiddle with baffles.
Now, if you have a dynamometer to hand and ability to design and manufacture your own pipes........

[Mark58]

thanks again for all the replies, i must take this exhaust system off and have a good look at it and what is in it. The replies concerning the back pressure issue are over my head to be honest. Even so I plenty of tips to try and see if it helps, not going to touch the ignition timing if i can help it. I am not in a hurry so could be a week of two before I try and sort it.

[sofiaspin]

If you post some pictures of your bike side on, exhaust side, close up of carb and surrounding area, and close up of exhaust system, plus primary side. Or provide a link, then that will give us a lot more information than your postings.

[Mark58]

Oh bugger i have had a frustrating old time trying to download my bike photos to this forum, i have followed scally's advice which i found concerning transfering a code via tinypic photo sharing website!! Anyway life is to short to muck about any longer, back to my electra x mysteries .
The exhaust is now off and i can see that i have a straight through silencer with a downpipe that has a smaller size pipe welded in visable at the silencer connecting end of the pipe. It doesn't look like this smaller inner pipe can be removed or cut out. The downpipe has a clamp and tapered end to fit into the head as described by folk on this thread. The need to torque the exhaust clamp has been mentioned, what would the torque setting be for the two retaining nuts?
On to main jet size with the above exhaust system following advice from your good selfs a 117.5 main jet seems to be needed due to the restriction in the down pipe, I have a 110 in the CV carb.
While fiddling with the bike I noted timing marks on the rotor, surely that suggests the timing can be checked? otherwise why put them there in the first place?

[papasmurf]

The "smaller pipe" is a catalytic converter.

[PeteF]

Can you see where the Cat is tack welded into the outer pipe?
Grind/cut the tack welds and it should come out.