Project 550L Trouble

[Guest]

Hey guys,
I hope I'm putting this in the right section. But i picked up a gs550L (maybe a 550T?) in a trade a little while back and having a little bit of trouble getting it running that i'd appreciate help on. but Let me explain the situation.

This is an electric start only bike with CV carbs.
I am eventually looking to do a 650 top end swap, and I've actually already gather the carbs and top end off of a 650E.
But I would like to get the 550 running currently before i start to do any bigger modifications.

First, the bike has no airbox, some come filters are fitted to the CV carbs (with a stock exhaust).
I have the stock mikuni 92.5 main jets along with 100s and 105s.
I have the factory 40 pilot jets along with 42.5s and 45s.
Carbs have been cleaned multiple times; this includes 24+ hour soaks in carb cleaner dip and multiple checks that all passageways are clear.
Intake O-rings have been repalced
Oil has been changed
bike has compression and valve clearances have been properly set.
The coil relay mod has been done, and now getting full voltage at the coils and all plugs have spark.

The problem is that the bike has an EXTREMELY hard time starting regardless what jets are used, and always requires starting fluid.
once running, i can usually get it to idle, but not very well. and any touch of the throttle will cause it to die down (followed by a high rev when the throttle is let go)
sometimes certain pipes do not get fully hot, but the pipes that are cold seem to be random and is not consistent.

I almost want to just jump into the 650 top end swap, but would really like to get the 550 running correctly first.

Does any one have any direction on where to go with this, or how else to start diagnosing?

[habsdoc]

If pipes are not getting hot and you do have good spark then you need to next check for fuel. Either to much or not enough fuel. Look at your plugs and see what they say. Change your plugs around from the cylinders that are getting hot to the ones that are not. Do the same cylinders still get hot or do the other cylinders now get hot??? Starter fluid used constantly will wash(burn) away your protective film of oil causing more wear and tear in your engine. To me it sounds like you are really lean on your carb settings. Try richening up the non firing cylinders.

[GSCafe]

Lean condition? Plugs in the correct order? I know I had to really tune my carbs to get my bike to not be cold-blooded. You might need to raise the needles a little. I'm guessing that if you are comfortable swapping the top end, you can handle some tuning. I'm not really sure how easy CV carbs are for this. I have the old style on my bike. If you can get the stock airbox and get it running as stock first you might save yourself some time and grief on your way to your top end mod.

[cowboyup3371]

Have you checked and adjusted the valves? They can cause hard starting as they get tighter.

[slink6333]

thanks for the tips so far guys,
so first of all, I have adjusted the valves because I've heard that they could be an issue with starting, but they are all within spec now.
Ill agree it does sound like a lean condition, but i have checked all of the likely problems such as the intake boots and orings to make sure they are ok.
Obviously the lack of airbox will cause a lean condition, but even with 105 main jets in there, it doesn't seem to make a difference on starting.
I would think 105s would be way to rich anyways, I'm thinking the 100s that i have would be the better starting point.
And yes im pretty comfortable working on carbs / tuning them, though I will admit this is my first time with CV carbs as I'm much more used to slide carbs.
Also i have already raised the needles slightly using the washer method on the cv carbs.

I will double check the plugs are in order (though I'm 99% certain they are), it does feel like i"m missing something obvious though
And ill make sure not to over do it on the starting fluid, but will check which pipes are getting hot next time i get a chance to go work on it. though if i remember correctly, the cold pipes were not consistent and seemed to be different each time running.