Amal 626 Trident carby bottom end thoughts

I believe I have an Amal bottom end issue with my Trident ~ but is slightly complicated ~

I believe I need to put the bike on a Dyno

The carbs went progressively to crap ~ and I checked everything ~ tappets ~ static and dynamic timing ~ replaced the plugs ~ only thing I have not done is replace the coils ~

The bike was bogging on initial throttle opening ~ now we know I have on going clutch issues!

The bike runs fine above stage one ~ But initially it would actually misfire on one cylinder at just cracking the throttle on stage one. I tweaked the carbs to over come this ~

It would not pull up our driveway which is a fairly steep incline unless I take a run at it and give it virtually ½- full throttle ~

But it finally would not even pull away from our driveway last time the boys picked me up to go the Sunday Classic meet ~ I had to HAMMER the throttle and really thrash the clutch ~

So I pulled the carbs off ~ (these being the Super build carbs ~ with anodised slides and precision setting and tensions ~)

I replaced them with a set I built myself. The bike was instantly transformed! Even the exhaust note at idle was completely changed ~

So rather rather than upset any of “Bob’s” precision settings I removed the top linkage shaft and removed the top hats with slides intact~

Both carbs at stock all new identical service parts, all jets, needles etc in older bodies ~

The circlip / needle were set at the third or bottom slot. I reset this to the middle which I know my own build set are!

I refitted them and then retuned ~ I left the air filter off and then took the bike for a run and it is HOWLING ~ Blew me away at the result !! It was flying!

Then I refitted the stock filter and the result was the edge was off the performance! (So I have ordered a K&N filter to suit. It is yet to arrive. )


Now ~ the bike pulls away far better from standing and performs well at the mid to top range ~ I generally ride at 4500- 5500 rev range ~

But here is the clanger ~ It still struggles to pull up our driveway and has an inherent spluttering through the exhaust ~ on lwo revs !
It does not miss ~ or back fire in any way ~ just this annoying “farting” – spluttering~ through the mufflers.

I am running T120 mufflers ~ should be A65 really as they have a different back pressure issue as in the T150T Beauty kit. I was concerned about back pressure but that is only effected on high end (??) And it has Viking Big Bore pipes ~

I think as said I need to run it on a dyno and exhaust gas analyser!

Any thoughts?

You don't think your miraculous fuel milage may be related

Splatt

The thought did cross mind .. but for all the wrong reasons coz the needle was set at the richest position ~ ????? I checked the plug colour after ride on Weds and they looked fine !

Maybe we should talk about the ignition and charging system on your bike.

Hey TT

A new replacement Tri-Spark from bought in 2007 ~ replaced <March 2012>

Alternator essentialy stock unit with electronic rectifier~ appears to be working just fine ~ plus Mottobattery new ~

Ive yet to see a Concentric , that doesnt cough & splutter .

If you put bigger ones on , itll lurch further forward at ea Cough .

seriously , Dang THIRTIES are the Go . on daytonas too . A aqaintance ran a T16o and threw out the E.S. and fitted 30s and got F.T.D. at some Sydney thing about 1980 .
There was a bit more to it than that , though .
Got rammed by a Katana at a circuit later , split pelvis , smashed legs & other incidentals . Somewhat annoyed by that . And not without good reason .

Saw Des Wests Holden FJ this weekend. Had Three MINT Amal 1 3/8 in G.Ps on it . Now , if youd asked earlier , I wouldve known what they fit .
The Odd Chap ( Neumerically not intelectually ) fits 32s to Tridents , particularly if bored or stroked / Both actually and theyre not a bad idea .

Olde T100 daytona mill ran 30 Conc, on rubber , to out drag stock 650s .The stutter is irrelevant , if its behind you . Harder Plugs maybe too . N 57 R s . :?

Hi Stuart, you have two banks of carbs so you can compare the new set with the set you built yourself.

Float levels need to be checked and compared with the old set and you should have a figure for the Trident. If not, Les Williams will tell you. Also, do check that the slides are synchronised if you haven't already done so. If it idles happily and evenly, then you know the pilot circuitry is clear, but if not, then you will have to make sure each pilot circuit is clear. What happens to the throttle response if you richen the pilot circuits at idle?

If it idles OK and pulls away OK from a standing start on the level but not up a hill, it might be running lean on the cutaways (throttle slides). Does it improve if you let the choke slides down slightly?

You can check the number on the slides (e.g. 3, 3 1/2, etc). You can also measure them with a calipers at the apex (i.e. the middle of the arc) with the slides vertical on a flat surface. Compare with the old set.

In the meantime, I will ask a friend who has recently fitted a new set of Mark 1 Concentrics to his T150 for the settings he uses.

Hope this helps.

Dave

Thanks to all for your input~

Matt

Putting 930s on a Trident is only beneficial IMO to one to go street / racing racing ~ I actually bought Mikuni 30 mm or was given a set by Dave Madigan in California ~

The bottom line was that I am looking for a Sports tourer not a street racer ~ and I while do give the bike heaps and spin the tacho regularly around to 6K that bench mark is quote` ~ "Not really trying , Stuart! " The larger venturis lend to high revs ~ and thats why I dropped the 30 mm's ~

Many of my Tripler mates go beyond the 6K mark ~ But I plan on getting a long life out of my Trident ~ Not spend time rebuilding the engine because the oil pressure is failing ~ and in the worst case scenario ~ picking up pieces because con-rod has 'left the building' !

Dave

The Super carbs have been built by a retired mechanical engineer who know all thing fuel delivery . ( In fact "bob" owned and ran one of the highest rated drag rail race teams in Ozzi. He regularly writes analytic articles to our Oz Triplers group which are reference manuals in them selves and most save them as such!)

No admittedly when he first built and sent me the Super carbs they would not run on my bike so he insisted I return them and he and "Snibor" spent soem time sorting them ~ (Snibor you may have come across via TOL and several other bike sites. Steve himself is no slouch on triples and only just completed another tour of duty at the Manx TT)

On return they worked "fine" ~ I have put in some 1500 miles and things started to deteriorate ! I checked everything short of replacing but the coils. That included the Tri_Spark module as it seems there is a problem with earlier Tri-Spark units which I had also. So I am assuming that is fine!

Additionally the floats I believe to be spot on ~ Plug (NGK Be88) colours are fine but look a tad rich on the outer body of the plugs but are consistent ~ ( I have been assured that with ULP fuels it not quite as easy to read the plugs aas was with the old leaded fuel. BTW- I run 98 in both the Commando and the Trident.)

SO ~ the slides are in place and fine ~ air jets responsive and appear Okay! I adjusted the needles for the third or lowest slot to the middle slot.

The bike runs at speed a World apart and better than previously but I am getting that popping at low revs and take off ~ And being perfectionist Iwant it right ~

NOW ~ I am waiting on a new complete clutch assembly from Charlie Barnes aka Triples Tech in San Francisco . The clutch is not 100% but works ~

So after getting emails from Bob and another Classic restorer (also a Tripler fan) in Melbourne they both agree/suggest I try raising the clip to the top notch ~ as they agree altitude could be an issue as well ~ as I am at 2000 feet where as they are all at sea level ~

Finally another Tripler mate who is the professional restorer in Brisbane aka TTRest on TOL still argues the exhaust is an issue with the Viking Big Bore pipes and T120 mufflers which add up to a straight through system ~

So today as I have a RDO I will raise the needle clip, and consider fitting SS baffling inserts ~

Thanks again ~ Let you know !

Yes, keep us informed - it adds to the bank of knowledge that we all need to draw on from time to time!

Okay ~ Taken the option of removing the top caps ~ so I do not upset any of Bob’s "precision setting” elsewhere.

Raised the clip to the top slot on the needles ~ from the centre possy!

Refitted just now ~ retuned to suit (with cooling fan up front.)

Even more crisper exhaust note ~ throttle response very sharp .. idles superbly~ not quite as lumpy as previous two settings .

No lumpy firing just off or above idle ~ seems much more smoother as anticipated or is that hoped for !

Weather has returned to Winter ~ raining ~ windy ~ Just have some lunch and see if weather fines up any !

And see it goes as well as we anticipate !! ?? And worse still .. face that dreaded ~ driveway ~

Actually here is the original U-Tube clip the first run I ever did ~ with my own carbs ~ and the original Barnett clutch plate ~ Consider how well the bike effortlessly scales that drive way ~

http://www.youtube.com/watch?v=iASWUcVB ... ature=plcp

Now ~

I Just took the bike out despite the drizzle ~ set on the top groove notch ~

Totally hopeless ~ absolute ~ disaster ~ would not run as soon as it faced a rise or even acceleration ~ ( Great fun in the rain! NOT! )

I never even tried to go up the drive but went to the back fence neighbour’s drive way which is on higher ground to our place ~ and came back to the garage across the immediate neighbours front lawn !

And yes - it is like starting off in second gear ! ( I also rechecked gear box sequence both on the road and now in the garage by hand ~ )

So I will refit to the centre notch the same as my own set ! I figured the top notch would never work !

I will refit, & recheck headers for leaks ~ reseal up as required ~

If I understand you right, you had the needles on the middle groove and the motor struggled a bit uphill. Then you went to the weakest position and it wouldn't pull you out of bed. You now know the mixture is lean under those conditions and throttle opening. Why not fit the needle clips to the lower grooves (richer) and see what happens?

daveh said:

If I understand you right, you had the needles on the middle groove and the motor struggled a bit uphill. Then you went to the weakest position and it wouldn't pull you out of bed. You now know the mixture is lean under those conditions and throttle opening. Why not fit the needle clips to the lower grooves (richer) and see what happens?

Click to expand...

Or.......... why not fit, if you find you need the needle between two grove for best performance, a brass washer under each clip to raise the needle half the height between the two groves.

Dave''

I totally agree ~

And that's the plan ~ BARTTtt~

First I have refiited my own build carbs ~

I fitted and tuned up` Amazingly .. again the engine throws a totally different sound short of course being a four stroke triple !

So NOW ~

I will run again on Saturday ~ as it is raining again ~ ( I did the run today in drizzle then to rain .. 8) Of course you do realise that in fine tuning, humidity levels do make a big difference !! 8) )


Oh ~ Bernhard~ That's agreat thought for really fine tuning ~ not heard that one before ~ 8)

I have fine tuned a few carbs in my time, and I can tell you if doing just one cylinder or more engine you cannot beat a Colourtune kit, (used in the Dark) and with two or more cylinders, a set of vacuum gauges to get the tick over and throttle response spot –on.

Needle groove is a coarse adjustment. If it runs well on the middle notch, in the throttle position where mixture is controlled by the needle taper, it will be obviously rich if you raise it a notch and possibly dangerously weak if you lower it a notch. That's the sort of reason I don't have much idea what is going on between you and this bike.

If you do get into shimming the needle clip, to get less than a notch adjustment, it's easy to make shims out of card.

Okay

Saturday afternoon ~ 1300 hrs.
Just returned from my latest road test.

I put in about 50-60kilometres (My bike has a metric GPS Speedo!)

I fitted my own rebuild carbs, while not the excellence of Bob's skill, are certainly nothing to be ashamed of either IMO ~ and are totally stock Amal 626 by the workshop manual to suit the 750 Triple.

This included extensive hill country and lots of twists turns. Additionally it included highway cycle , mostly tarred road , town and even around 5 kilometres of dirt~ including again lots of hills ~

Fine Sunny day, around guesstimate 70% humidity~ no dry lips but dry!

First ~ Fires first kick ~ idle is great, even cold! No fluttering or spluttering at ANY levels~

I fitted my pod filters ~

The performance is excellent~ accelerates superbly~

Now when first started and run there was no popping from the exhaust~

But as I went on there was a little but not so bad.. I am thinking Bob could be right and I still have some small exhaust leaks causing the popping. Will look into it ! But I can put up with that level~ No where near as much as my Commando and I know that it has leaks ..

(I Challenge anyone to show me a balanced pipe Commando that is sealed 100%)

But overall the bike is pleasure to ride and I did not have to wrestle with it at all ~ I deliberately endeavoured to ride in a comfort rather than race mode.

The bike is smooth and pleasant at ALL levels ~

I stretched it out after about 5 klicks and pushed with ease to 145 kmh ~

No problems ~

NOW for the BIGGY!!

I rode out the highway and about another 5 klicks out there is a sweeping down hill turn on the highway ~ and about at the bottom there is a right hand turn off and the road immediately goes into a steep uphill climb ~

I turned into this and brought the bike to a slow rolling first engagement that I would do at home ~ then endeavoured to climb this hill which s a lot steeper than our driveway~

It pulled up the hill with NO effort or complaint in the least!

So I continued along this road which went to gravel and I figured would be another test of engine tractability/ flexibility ~

So completed another 5 K in 2-3 gear without struggle or wrestling ~

Finally I returned to base and again.. the DRIVEWAY !

I brought to a rolling first gear and then up it went .. NO PROBLEMS AT ALL ~

So NOW?

Put the Super carbs back to the centre slot ~ and check th e headers and mufflers for leaks ~

I plan on gleaning some riding pleasure from this beast first!
Then I will refit and play around with them after all i paid big dollars

(Although I bet you could buy new Amals of such a high standard and guaranteed to never wear out fo rthe same money ! )

So if the carbs you built yourself are delivering the goods, keep them on and enjoy riding the bike, and save the Super set as a spare, or sell and get some of your money back? You've obviously done a good job with the bank you built yourself, and maybe you are wondering if you really needed an expert - good as he may be - to build the other set?

Dave
Good thought ~

I am definitely planning on getting some miles down and pleasure to recoup the misery of late !

I have said it before that maybe Iam not the sharpest tool in the shed but obviously my rebuilding skills are not lacking ~ Lesson for many of us.. don't under estimate~ or under rate your own abilities ~ 8)

Of course as was said to me this afternoon ~" The cream on the pie would be to do a few fuel economy test/s and see how your own carbs compare to the 59 mpg of the Super Amals ~ and of course get a comparable rate ~" :lol: 8)

In fact I am planning to do as you suggest with the clutch once it turns up from Charlie Barnes in USA ~ I sell on the lightened clutch components I have currently fitted to the same bike ~


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