Performance problem

[redmidget]

Although I'm Ok with most mechanics, engines are not my best subject so I would appreciate some ideas - my 750 Paso starts OK, normally without choke, then runs fine for about 30 mins before it starts to struggle - cutting out, loosing power, surging etc - feeling a bit like the choke is out when it isn't. I coax it home then if I put it away for a while and take it out again it repeats the performance. Any ideas please??

[silverfox]

What carbs do you have on it? Original Weber, Mikunis ?

Tony

[higgy]

next time it acts up,open your fuel lid and see if it makes any difference.
also try putting the choke on while it acts up
You have not given enough info for a reliable diagnosis but there are a few things you can do that are easy that can help
point you in the right direction

[paso750]

as higgy says it`s quite difficult to say something from the distance as it could be all kinds of things. Ignition, carburation, electrics etc. Battery is full, fuel filter is clean (also the one of the fuel petcock in the tank) ? Is choke really off ? Sometimes it stays open a bit although the lever is on OFF position. It was mentioned somewhere in this forum before. But if the bike ran well before this can be excluded.
If you do have starting aid spray (or however that stuff is called) you can try to spray something on the inlet manifolds the next time the engine starts to struggle. If the engine does not react in any way you can at least exclude air leaks also.
All just guessing for the moment.

G.

[ducinthebay]

Could also be your coils. Old coils will run fine when cool, but when they warm up the begin to short. they do die after some time, and 20 year old coils can't be trusted.

Cheers,

[fredskidoo]

Here is my 2 cents based on having the exact same experience.

First off:
I ignored my intuition for weeks - A State of Pure Denial.
I had spent $100 to have my gas tank cleaned of rust, etc.
rebuilt the weber, replaced the fuel filter and all the fuel lines
just two months prior to the development of our common problem
With all this I confidently ruled any problems with the fuel system out.

Secondly:
In my denial I speculated, vacillated, deliberated and
procrastinated the inevitably inevitable - full dis-assembly.

Finally:
Well needless to say, after many days of wire giggling, switch
switching and ground grounding I removed the gas tank and
removed the petcock and fuel float and while draining the fuel
I was shocked (mainly over the $100 spent!) to discover my tank
had accumulated a variety of S#!T - leaves, earwigs and RUST!!!

So if you have EVER ran out of fuel I guarantee your fuel tank "Other"
contents will find their way to your petcock and your petcock will
become clogged - mind you - intermittently. So if you experience
any stumbling (beyond the readily apparent weber issues), poor or very
odd throttle response sensations don't just suspect your inline fuel filter
- pull and clean the petcock and flush the fuel tank - thoroughly.

[higgy]

that info/rant gotta be worth at least 25c maybe even a dollar
always read the directions always...........

[ducinthebay]

I have often found that the last thing touched is the cause of the problem. Someone brings me a car or bike that doesn't work right, and I have to ask, "what was done to this most recently?" Often you get the response, "it ran fine until I tuned it up."

Glad you found your problem. Hope you got your $100 back.

Cheers,

[redmidget]

Thanks for the tips, I will work my way through your suggestions starting with the simple ones. It has come about suddenly and without me having done anything mechanically for a while - but the fuel did run low in the tank. If I was asked to describe it it would be like riding with the choke on so the sticking choke might also be a possiblity. Thanks again.