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Discussion Starter #1
Recently bought Norman Hyde peashooter silencers for my 1997 Adventurer.

The bike is now emitting wee puff of black reek (smoke) when I blip the throttle and a momentary reluctance to rev - almost cutting out as if there is too much or too little fuel?

I also replaced back shock with Hagon unit (big improvement, which wasn't difficult as the original had lost all of it's oil!!). To do this job you need to take off the air box intake unit next to the battery. This is held on by a jubilee clip which I think I tightened properly - I'll check this.

I read somewhere on this forum there is an adjustment on the carbs that most guys reckon should be two and a half turns out - what and where is this and do you think it's linked to the black reek and relcutance to rev?

Norman Hyde state that no rejet is required for these silencers - hope so as I'd need to get the shop to do this as I've never tackled this type of repair before therefore I'll probably be charged a lot.

Any help is much appreciated

Jim
 

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The Hyde silencers should run well enough on standard jetting I'd have thought. The 2.5 turns out refers to the pilot jet fuel screws, recessed & vertically underneath the engine side bellmouth on each carb. The centre one is a b*&^%$d to get at on the bike, but they're not so critical & needy of tweaking with engine running in my experience. Whereas, carb balance, using a vacuum gauge, is sensitive & important for good tickover, pickup & rolloff. The cable acts on the centre carb & the outer pair sync'd to this. This may well be your problem, but you'd be wise to check the carbs & jets etc are all clean beforehand. The pilot screws stock setting is rather lean (~1.5 turns) even for stock pipes, so it's worth resetting them. Sliding the carbs out is considered a fiddly job by many (putting it politely:D) but once you've done it a couple of times it's quite easy. I don't disconnect the throttle cable which saves a good bit of head wrecking. (And on Keihin carbs, wrecking the cable too.) I just slide 'em out to the right & drop them onto a 'workmate' bench or similar next to the bike.
Inspecting/cleaning or changing the airfilter while you're at this would also be a good idea. Note that if the oil is filled more than half way up the sight glass (correct level), the engine breather can chuck a bit of oil into the front airfilter box.

I think you suggest you're not very experienced mechanically, but I hope this gives you some background to understand things. And I'd certainly encourage you to have a go yourself, get a manual (Haynes) & a mate to help maybe as two heads are generally better than one & an extra pair of hands goldust when you're learning.
 

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If you haven't done anything beyond install new silencers, I'm wondering if you may just have some bad gas passing through the system.

You really shouldn't have to do anything beyond tweaking the idle mix unless you messed around with the air intake.
 

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Discussion Starter #4
Big Al I thought today that it could be the petrol. I usually buy the petrol at the supermarket and it's not always the best.

Once I've run her fo ra few miles she responds beautifully with no black reek or lack of response. I'm going to have a look at petrol additives to give the innards a good clean out - any suggestions on this - do the ywork or am I just literally burning money (literally) with no real effects????

Thanks IrlMike for your technical knowledge - I'm not bad at the bike stuff like shocks, wheels, etc and really enjoy this but I've never done anything like balancing carbs, shims, etc and that's where I'll have to stump up big cash to get the shop to do it. I've got a haynes manual and rate it highly the way repairs & installations are methodically described.

It's probably fear of the unknown or fear that if I balls it up then the shop will make even more money from me to rectify my tinkering!!! Still I'm willing to learn and hope to enjoy many years with this bike.

Done quite a few mods to bike in the year I've had her - maybe someone can refresh my memory on how to post photo's and you can judge my efforts for yourself.

Jim
 

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Once I've run her fo ra few miles she responds beautifully with no black reek or lack of response.

Jim
That kind of suggests to me that once she's warmed up she responds beautifully....

Which implies a slightly (really not much) weak mixture - exactly what you would expect from fitting those freer flowing pipes. As the stock pilot (fuel) screw setting (~1.5 turns out) is known to be 'weak' even on stock pipes, resetting these to 2.5 might prove well worth it. From what you say you have more than adequate tools & ability to slide the carbs out & do this. The choke cable slides off easy. Take the tank & side panels off. Note the tank vent pipe & anti-tip valve (if there) routing at rear left side & have some superglue handy for the airbox side panel fixings in case they are brittle & break coming off. Remove coils. Loosen the carb rubber clamps at the carb side only. Jiggle & slide carb bank out to the right, throttle cable still attatched. (Move a plug lead as needed.) There's just enough room - watch for snagging wires etc underneath. Have a bench or some such of the right height positioned to the right of the engine to drop the carbs onto. I place them in a specially fabricated tray to catch any fuel leaking from the float bowls. (Ok it's a biscuit tin lid :D..) Carefully screw in each idle screw until it just seats & note how many turns. Then you can unscrew each fully out & check they're clean. Note the spring washer & o-ring positions. Reinsert them fully then back off the 2.5 turns. You may want to drop a float bowl off (4 screws) to see if there's any muck inside - should be very clean.
Read your manual first & compare with my suggestions to make sure you have all the steps understood. Watch nothing gets in those open inlet ports when you have the carbs off - I put a cloth over them to be sure...
That's pretty mutch it - when you've mastered this you'll be raring to get a vacuum gauge set (Morgan Carbtune has been good for me) & move on to doing your own carb balancing...a very satisfying job :)
Good luck!
 

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Discussion Starter #7
IrlMike thanks for the inspiration and vote of confidence in my abilities.

Had a look at the carbs today to discover they are Mikuni units.
They have the pilot jet screw to the side of the of the float bowl, including the middle carb, for easier access. They not on the underside of the float bowl as you describe for the Keihin units.

This appeared to be good news as I assumed I would not have to take carbs off the bike. However,.........!!!!

I am now the sixth owner (bike now 11yrs old) and previous owners and/or their mechanics have all but chewed up the screws to the point I am not going to attempt make matters worse, which will require the carbs to be removed and new screws put in - unless I can get long grips into the middle carb - probably not too easy.

As the current setup means the bike runs a bit weak and as this is the way the pilot screws are set at the factory (is this to do with emission controls??) I'm going to use the bike the way she is.

I won't be using her much now as the local council has started the annual free rust for all season - i.e. several inches of rocksalt on the roads (to stop ice forming for you lucky people who don't have this).

If I leave the mixture lean will this damage the bike in any way? Seems to be good for mpg as I currently get around 50mpg. I'm not that bothered about mpg but it's still an advantage the way fuel prices are now.

I don't want to start any works that could result in potential damage as the cold weather makes parts brittle and subject to being broken more easily.

Renewing the pilot screws will get done - are they easily available for Mikuni carbs?

Thanks again

Jim
 

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Ah...should have realised you have Mikunis - throttle cable attatches between centre & left carbs so they won't slide out to right as I described without detatching said cable, tho' it's a little easier than on the Keihins. IIRC they would slide out left enough to change/set idle screws with horn removed.

Being a little weak will not likely cause any problems (as Hyde have said) & I believe the stock idle screw setting is for emissions reasons. As I mentioned before, carb balance is way more critical for smooth pickup/idle than pilot mixture (within reason). You can always whip a plug out & check for colour/burning. All the aftermarket plug suppliers seem to recommend hotter running heat range '8's rather than the official '9's listed by Triumph. This would suggest there's no danger of overheating & been my experience. Plugs look nicely clean but no signs of stress.

Your mpg sounds fine on standard gearing. (Going up to 19t/42t gets me over 60mpg.)

You can buy the pilot screw as an assembly from Triumph - but expensive I think.

You may be able to buy from here cheaper:

http://www.allensperformance.co.uk/index.html

Not dealt with them myself, but I got the link from the forum a while back.

Commisserations re the salt, a real pain for bikes. We don't get much here thankfully. Hopefully you'll get some decent days...some great roads & scenery there in Scotland.

Cheers
Mike
 
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