'91 Trophy 1200 running issue

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B

Borderline

Active Member
Hi,

Having a problem with my recently purchased '91 Trophy 1200 and looking for suggestions as to what might possibly be causing it.

When I collected the bike it ran faultlessly for the first 100 mainly motorway miles then as I hit city traffic it began to falter. The first thing I noticed was a reluctance to accelerate as if it was running out of fuel (it wasn't, it had at least two thirds of a tank) followed by the idle speed dropping from it's usual steady 1000rpm to a rough 750rpm. It would also stall from take off unless it had a handful of throttle and lots of revs. The next day it ran fine for 20 miles or so then the same symptoms appeared. Now it can happen as soon as it gets hot, especially in traffic.

I've checked all the fuel pipes and they all seem to be kink free and fuel flows from the tank OK. As soon as the bike cools it's fine so wondering if it could be the coils? I've checked the resistance values and they are all within spec but then that's when they are cold.

What do you think - fuel or coils or something completely different? Any suggestions and comments welcome.

Thanks, Gray.
 
My first guess would be the coils failing as it gets hot under there.

Another typical issue with these bikes is a clogged fuel cap vent. This could quickly be ascertained by opening the fuel cap and seeing if it corrects the problem.

So I would suggest eliminating the clogged vent as the culprit first, then move on to the coils.

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The first thing to try is loosening your fuel cap as soon as it begins to falter. It you hear a whoosh, and it begins running fine, your fuel vent line is plugged up.
 
CarlS said:
The first thing to try is loosening your fuel cap as soon as it begins to falter. It you hear a whoosh, and it begins running fine, your fuel vent line is plugged up.
Click to expand...

The one problem with that is that Trophys have locking gas caps which are unlocked with the ignition key :)

PS: there is no fuel tank vent tube per se but only a vent built into the fuel cap collar.

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Cheers Guys. Forgot to mention I've tried opening the fuel cap as soon as possible after it plays up but makes no difference. I've noticed the fuel cap 'whistles' quite a lot and sometimes for hours on a hot day although I think I read somewhere this is normal?

I think I need to eliminate the coils first as it's still running on it's original 1991 ones. Any tips on the best replacements?
 
Borderline said:
Cheers Guys. Forgot to mention I've tried opening the fuel cap as soon as possible after it plays up but makes no difference. I've noticed the fuel cap 'whistles' quite a lot and sometimes for hours on a hot day although I think I read somewhere this is normal?

I think I need to eliminate the coils first as it's still running on it's original 1991 ones. Any tips on the best replacements?
Click to expand...

I was going to mention that in a quiet place, you can hear the fuel tank whistle as it vents....lol. Yes, that's normal.

Best replacement coils without a doubt are Nology!

Please look at the TriumphTalk Wiki under the Trophy for details on coils.

PS: sometimes previous owners don't get the heat shrouding back in place correctly after removing the tank and changing the plugs, so while under there - check it out. That shrouding is very important for keeping those coils cooler and making them last longer.

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The Seeker said:
I was going to mention that in a quiet place, you can hear the fuel tank whistle as it vents....lol. Yes, that's normal.

PS: sometimes previous owners don't get the heat shrouding back in place correctly after removing the tank and changing the plugs, so while under there - check it out. That shrouding is very important for keeping those coils cooler and making them last longer.
Click to expand...

Thanks for your help :y16:

Couple of extra questions though: The tank whistle is driving me mad ANGER I can hear it indoors when the bike is in the garden and now the neighbours have asked where the noise is coming from! We're having a bit of a heatwave here in the UK at the moment so that's making it worse but surely it shouldn't be that noticeable. Could it be a sign of some sort of blockage?

I removed the heat shroud today in prep for some new PVL coils that should arrive tomorrow and noticed there was a piece of 'foam' missing that's shown in the manual. Does anyone know the part number or anywhere I can buy one?

heat.jpg
 
You can barely hear my tank vent whistle in a quiet garage. It is definitely not so loud that anyone could hear at any distance so perhaps there is a problem.

You can undo to whole cap assembly by removing the hex head bolts and clean the vent.

Any Triumph dealer should be able to ID the foam part for you. I would think the only place to buy one would be a dealer or breaker (junkyard) that happens to have a 91 Trophy.

Posted with TapaTalk
 
I think I'd better have a go at cleaning the vent as I'm sure I just saw next door's dog walk past with his paws over his ears!

Sorry for the obvious second question. I'm used to owning fairly recent Japanese bikes and have been spoiled by the abundance of spares etc. Must get into 'Old Triumph' frame of mind :y2:
 
Borderline said:
I think I'd better have a go at cleaning the vent as I'm sure I just saw next door's dog walk past with his paws over his ears![/B]

ROTFLMFAO!

Sorry for the obvious second question. I'm used to owning fairly recent Japanese bikes and have been spoiled by the abundance of spares etc. Must get into 'Old Triumph' frame of mind :y2:
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Just guessing, but I would think Triumph dealerships are further and fewer between here in the USA. I would think you could ring one and explain what you needed to the parts guru and have them mail it too.

I have never seen a parts manual made for Trophys......I believe only dealers have access to the microfiche.



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Hi There nick160460,

This is spooky as I've just ordered that part from World of Triumph a few minutes ago! :y13: Thanks for taking the time to look for me though. I'm new to Triumph's so am still at the learning stage and finding out the best sites etc.

Haven't actually had the bike cut out on me so hoping the crank sensor is not the culprit.

Yes I saw your Trophy pictures in the Gallery - what an excellent example. Great bikes aren't they? Whereabouts are you in the UK?

Just noticed you are in Hampshire. I'll get the hang of this forum eventually!
 
The Seeker said:
Just guessing, but I would think Triumph dealerships are further and fewer between here in the USA. I would think you could ring one and explain what you needed to the parts guru and have them mail it too.

I have never seen a parts manual made for Trophys......I believe only dealers have access to the microfiche.
Click to expand...
Managed to download the Trophy microfiche so if anyone needs it give me a PM.
 
It comes in two parts - Triumph Trophy up to VIN 29155 and VIN 29156 onwards. Had a quick look through and yes it covers the '96.

Also came with Haynes Manual for all Triples & Fours from '91 to '99 plus Accessory and Clothing Part Numbers on PDF's.
 
Awesome! Thanks.

I have the Haynes manual in hardback form....how 20th Century!

But I have never had a parts manual. That's something I've only seen at the Triumph dealer.

I'm on my phone now, but I'll grab that on my desktop PC soon.

Thanks again! TUP

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