Triumphrat

cafetbird · 10-05-2007

Having a bit of perplextion with the Birdy lately. When she gets a little warm, Nessie is having some trouble starting up.

She turns over very well, but just won't fire up. If I let her sit and cool off a bit, eventually she'll start (that is not always convienient though - the gang gets impatient, you know!). Sometimes adding a bit of fuel enrichment (aka-"choke") helps. I've checked the fuel cap - so it is not a vacuum issue.

It appears to be a fuel starvation issue, but since the bike has been sitting, the bowls should be full, right? Can anyone think of something I might be missing here? Next step is to give the carbs a good cleaning, I guess.

Thanks,

Scot

jimmyj900 · 10-06-2007

I'd take a look at the pilot jets on that. If it takes some choke when warm, then it sounds like it's a bit lean since it should run richer with the engine hot.

Use a magnifier on the pilot jet bores and make sure they've got that 'clean machined' look. It doesn't take much gunk reduce the bore into a lean condition.

Jim

cafetbird · 10-06-2007

Yeah - I am there with ya. Jimmy - just wanted to make sure there wasn't anything else I might be missing. My guess is they shrink a little when warm too, restricting flow further.

Thanks,

Scot

cafetbird · 10-13-2007

Still locking after a carb cleaning. Went ahead and changed the plugs and cleaned the K&N while I was in there.

It does seem to be a fuel issue. Pumped the enricher a few times today when it happened and the bike fired right up.

Probably going to pull the tank next - maybe a fuel flow thing....

WoodsieIII · 10-14-2007

Not that nasty little duckbill filter?
I constantly ride mine on 40 deg C plus days and have never had a fuel issue. Check also the filters on your petcock. I take mine out every twelve months and clean them and rinse the tank out as well.

jimmyj900 · 10-14-2007

Have you checked the throttle and choke cable adjustments?

If either is too tight and the cable routing is a bit off you may see erratic starting depending on the angle of the front wheel.

A loose throttle adjustment nut at the carbs can also cause some problems.

(Yeah, it's one of those 'obvious' things that has bitten me a couple of times.

)

Jim

cafetbird · 10-14-2007

Yeah, went through all of those, Jimmy. Like I said, it'll start fine when cold, when you let it cool off for 1 1/2 hours, only not after about 30 minutes to 1 hour. Today, it would not start no matter what I did after going on a 10 minute ride and then trying to start it 1/2 hour later.

I am starting to question whether it is a fuel issue after today. It smelled flooded, and when it finally kicked over, let out a big back fire.... BANG!

I wonder if anything with the timing pickup could be contributing to it? Maybe there is an ignition gap somewhere in the circuit when the bike is warm? LOL - o.k. - I just went out and tried a couple of things:

1. Spray ether into one of the holes in the airbox. Tried to start twice with no luck (maybe I needed to a bit longer...)
2. Pulled the #1 plug and checked for spark. While I was checking this, the bike started on #2 and #3 cylinders only! *** was that?!?

Shaunlee · 10-15-2007

I was having the same problem with my T-Bird and after a lot of dinking around it turned out to be the rollover valve. Simple thing you may have already checked.

jimmyj900 · 10-15-2007

Well, if the jets are clean and the cables are properly routed/adjusted/etc., then it's time to dig a bit deeper....

Check your battery. A weak battery may cause intermittant firing at low rpms. At higher rpms the bike runs on the alternator.

It could be a couple of failed ignition coils. One coil won't be that big a problem with the usual 'weak spark' failure, but if you've got two or more coils going weak when hot, then that can cause low rpm symptoms that disappear over about 3500 rpm and/or when the bike has cooled down.

Another low rpm problem could be that the valve adjustments are too tight and when the engine heats up the compression drops off.

Kinda guessing here....

Jim

cafetbird · 10-15-2007

Quote:

Originally Posted by Shaunlee

I was having the same problem with my T-Bird and after a lot of dinking around it turned out to be the rollover valve. Simple thing you may have already checked.

Yeah - since I don't have one. Thanks for the suggestion!