Bonneville America Forums Forums Technical Forums Performance Mods Rough running and cutting out

Firstly, a big Hi from the UK

Right, last year I bought an 02 BA. As far as I know everything is standard apart from the standard length Triumph open pipes. Last year, every now and again the bike would apear to cut out for no more than a second, then cut back in with a massive backfire through the exhaust.

I have had the bike laid up since October and took it out last weekend for an 80 mile trip. A few miles from home it appeared to be running lumpy. Anything up to quarter throttle was rough but give it a good fistfull and it seemed to pull.

Yesterday I took it out and in town it was terrible, on the open giving it some it wasnt too bad, but not perfect. I have just taken the plugs out and they are clean, no fouling, no burning. I have turned the engine over with the plugs on the end of the leads, and the spark doesn't look that strong to me, but to be honest I am used to car engines so don't know how strong the spark should be.

The bike has done 11,000 miles. Where should I start looking?

Excalibur welcome aboard, sounds like it could be fuel related. Old petro? Carbs gummed up?
Here in the colonies we have a product called Seafoam. It is a fuel system cleaner. see is you can lay your hands on this product. Run a few ounces through the tank and see if that helps. I'd look for the easy way out first.
Mike

also be sure to check all the vacuum caps (squirrel condoms we call em) on the carbs for cracks or just gone. There are four of them and they will cause the problems you describe as well.
Toss the seafoam in the tank too and run that a while too.

cheers for that, I was wondering about carbs being gummed. The fuel is new as it dropped onto reserve a couple of miles after setting off so I filled it up with fresh fuel.

We do have fuel cleaning products, has anyone tried the aerosol types that you spray into the carb mouth with the engine running?

I am still baffled by this cut out and backfire though, it has always done this.

One other thing, I have just been onto Triumphs site, put in my details and it appears that there are outstanding recalls for this bike. Does anyone know what was recalled on the 02 BA?

The aerosol carb sprays will clean varnish and gunk off of what it touches in the venturi area......doesn't do anything for the float bowls and jets. This is the area you want to clean. Hence the "in the gas tank" cleaners.

It could be a vacuum leak or clogged secondary jets or air bleed passages.Since it does run at low speed, just not very well, it is possible that some fuel injector cleaner in the tank might fix it.
As for recalls, the relocation of the rear brake reservoir has been mentioned. Some bikes needed to have the power cable to the starter loosened and set to a different angle because they were eating into the return pipe from the oil cooler.
There is an unannounced recall on some '02 models to replace faulty ignition controllers. This was a 'replace as needed' recall, and some of the defective units never failed. The symptoms began as an occasional miss when the engine is fully warmed up, progressing to one cylinder cutting out completely, then both cutting out until the bike is allowed to cool down. Eventually, the igniter would fail completely.

Have the same trouble with my 03. Triumph workshop said to start at the begining, flush out the tank. I forgot to ask with what so i´m hoping someone here knows whats best.

Noticed that on my 04 speedy. I would give it some punch on the throttle and then no go on the acceleration then a pop on the exhaust then try the trottle again and there she goes. It has happened twise in the past week. Had my bike for two and a half years and 11000 miles and this is the first time it has happened. Is this the same problem you guys are talking about?

well, looks like it is cured and a quick fix at that.

The product we have in the UK to mix with fuel is called redex. I put in double the rcomended dose, a new set of plugs and thrashed it down a dual carriageway. Its like a different bike now and hasn't backfired once since

good news

I've never thought of using Redex....seen my dad put it the older cars loads of times....

I'll store that one for future reference...

Least you got a result.