93 Trophy 3 carb problem

[huddy]

Hi all,

Got a problem with a 93 Trophy 3, hope you can lend some advice.

As i have mentioned the bike is a Trophy 3 900cc 1993, with Mikuni carbs. Recently the bike has been mis firing and losing power in the mid range. We changed the plugs (which were covered with a black fluid) and cleaned the cards (as best we could with out a full removal).

The bike ran great for about 3 weeks and then the same problems reappeared. We are both know that the black film on the plugs relate to a carb issue, and looking around on various sites offer totally different solutions ( even to replacing parts that have nothing to do with the carbs h.

Now... the Mikuni site recommends just changing the jets to re-tune.

So has anyone had this problem and resolved it by changing the jet successfully or was thier other issues? :angry:

Thanks for your help :y115: :y115:

 

[Doug]

Unlikely to be a jetting problem as that would be a permanent condition and wouldn't go away with cleaning and then return.
Does the bike smoke? Exessive amounts of oil from the crankcase breather into the airbox would explain the appearance of the plugs and could be due,among other things, to over-filling the oil.You've checked that,right?
If it's not oil,then I'd start looking at the cold-start enrichment device(choke)to see if its shutting off properly.

 

[huddy]

Hi Doug,

The bike doesnt smoke. We havent check the airbox so will start there. There is'nt too much oil in the bike so wouldnt have thought thats is a problem.

My brother in law has menetioned that the porblems seems to surround one cylinder which is the right hand cylinder (when you are sat on the bike) he has swapped the coils over and that hasnt sovled it either.

We will check the airbox and let you know. :y18:

 

[The Seeker]

Trophys tend to have coil problems for which engine heat is to blame...it fries them.

They also tend to have petrol tank venting problems....the vent hole in the cap area gets plugged up.

Another common trouble is vacuum leaks in the hoses that control the petcock or a bad diaphragm inside the petcock.

There are also tiny fuel filters INSIDE the fuel hoses right where they go into the carbs....each hose has one so one could be partially clogged.

The airbox is ridiculously hard to remove, by the way.

There is a Trophy section of the TriumphTalk Wiki that you might want to read over....access it from the main front page of TriumphTalk in the upper left navigation section. Then scroll down to the Trophy.

 

[huddy]

Hi Guys and Gals

Quick up date....

Got the air box and carbs off the bike.

Air box good and clean

Carb one butterfly needed sorted, all done jets all good.

Loosly put back on and hey presto runs 100% better.........

New problem cant get the dam air box to fit correctly back on the the carbs, has anyone got any tips for this as it it driving me wild. Out of the frame the join perfect, in the frame they aint having it, nothing it the way at all!!!!????????


Sorry if this really sort an sweet, with spelling mistakes but 3/4 of the way through a nice bottle of red :y18:

Hope you all have an excellent christmas and are planning your new years parties.

 

[The Seeker]

Yep, the airbox is RIDICULOUSLY hard to remove/replace!!

The best method is to put the rubber hoses between the carbs and the engine in place but don't tighten them on either end. Put the airbox to the carbs, and slide them in from the side until they line up. It will have to be angled downward at the rear. Once it's lined-up with the carb rubbers lift the rear of the airbox and compress the rubbers hard until it comes into place.

BTW....some folks split the airbox and do this in pieces.

It is NOT easy, but it eventually will fit with some foul language, a bottle of good strong liquor, and some elbow grease applied.

 

[huddy]

Thought I would update all on the Trophy 3 problems... well they are all sorted now and running like a dream.

Had the carbs out, air box plugs, and just about anything else...bar the complete engine.We recalibrated the carbs as they were not closing enough, replaced the plugs and the air filter, cleaned out the fuel system . Everything was running fine but then she started missing again in the mid-range:y14:. A friend who owns 5 Triumphs called us, and would you believe it....... sorted the problem. It’s like this, the owner 2 back put race cans on the bike and altered the carbs so the bike ran better. Owner 1 back took the race cans off and replaced them with a stock original system but didn’t sort out the carbs. Which resulted in him selling the bike to my brother in law, not knowing how to sort the miss fire problem.

Well one quick connection to a laptop, and a reset to factory settings and guess what the bike runs like a dream. So the moral of this story is.... if you have problems with miss firing in the mid-range get the mapping checked before you start ripping the bike apart.

By the way is a (UK) Blue Triumph Trophy 3 900 rare? a few dealers have offered decent values for the bike which has a good number of years on it ( and mileage) and we don’t understand why

 

[CarlS]

Sure glad to hear you got it sorted out. And a relatively simple fix at that. Thanks for the update.