Triumphrat

gfiandy · 03-29-2009, 03:40 PM

Hi, I took the Daytona 900 out for a spin this afternoon. It was a buger to start and back fired at least once before it started. It didn't run well cold. Once warm it hunted badly at idle. On the open road it seemed ok and even at low speed ran ok. However it was really pulsing at idle.

ANyone any idea what sequence of things I should look at to try to fix it. I'd take it to a garage but my experience is they charge alot of moneyt and don't fix the problem.

Andy.

KitNYC · 03-29-2009, 04:48 PM

Off the top of my head... air leak at carb boots, valves, coils?

andrewb · 03-29-2009, 07:05 PM

FI or carbs?? no info in your profile

sailfish · 03-29-2009, 08:29 PM

Sounds like a mid 90's Toyota pickup.

Look for air leaks/vacuum leaks.
Balance the carbs.
The carbs might be dirty.

Mikunis or Keihins?

gfiandy · 03-30-2009, 03:47 PM

Hi, Thanks for the feedback.

It has Mikunis carbs.

Carbs were cleaned, had the float valves replaced and were balanced towards end of last season. I also replaced the boots to the head at that time. I guess it could be the boots from the air box to the carbs or I could have got something wrong, but it ran ok after it was balanced last year, not really smooth but nothing like as bad as it is now.

As it may have been getting progressively worse. I am thinking it may be valves which I have been putting off as I am not confident about doing it. I may have to bite the bullet and pay someone to look at it.

However I will check for air leaks first as that would be an easy fix and one of the balance covers could have come loose or the pipe to the fuel valve could be leaking. Mind you I guess I wouldn't get any fuel if that was the case.

I also noticed that it was a bit smother after I turned it off and came back to it a few mins latter. So I guess it had cooled a bit, it still wasn't smoth but seemed a bit less lumpy. Don't know if this points to anything in paticular, so thought I would mention it.

Many thanks for help so far.
Andy.

wdietz186 · 03-30-2009, 10:35 PM

If it is the first time out after sitting over the winter you may have partially clogged pilot jets.If your fuel over there is as crappy as the stuff we are getting here it's almost a given.As the stuff evaporates it leaves a brownish gum in the bowls and will clog the smaller holes like in the pilot jet.Sometimes fresh fuel and some time for it to melt the deposits will clear things but if you are going to pull things apart I would take the bowls off and make sure the jets and passages are clear.

sailfish · 03-31-2009, 09:55 AM

Quote:

Originally Posted by gfiandy

As it may have been getting progressively worse. I am thinking it may be valves which I have been putting off as I am not confident about doing it. I may have to bite the bullet and pay someone to look at it.

Yes, bite the bullet. The valve adjust is not something to delay as a leaking valve eventually becomes a burned valve. The service interval is 12k miles but I have shortened it to 10k as I had a valve that was essentially at zero clearance at 12k.

You mentioned it was better after it cooled off. That could also make the valves suspect as they get shorter again after a period of cooling.

gfiandy · 05-28-2009, 05:32 PM

I had the Valves checked and they are all OK. I have tried cleaning the carbs with no improvement. So since it seems to get worse as it gets hotter I am thinking it must be the coils. So that is what I am going to try next.

Does anyone know where I can get a set of coils at a reasonable price in the UK?

Thanks,
Andy

daytona 750 · 05-28-2009, 05:45 PM

it doesnt sound like a coil to be honest.coils have been my persistent problem over the last year, they tend to give a dead spot in the rev range when one drops out, and then a realy surge when it kicks back in.
your issue sounds like an air leak on the carb rubbers to me.
i have been known to be wrong from time to time, but of this i am fairly confident its your carb rubbers

Dittos3 · 05-29-2009, 10:31 AM

Air leaks cause a lean condition. Engines run at higher revs in lean conditions.

Start the bike and spray the carb boots with carb cleaner. If it races when sprayed, you know what the cause is. You might even locate the precise area giving you a problem.

Coils provide a spark. They have nothing to do with revs.

Ditto