Hard to start.........

[se3388]

I have a 1980 GS550 and rebuilt all 4 carbs when I got it and set the floats as well as balanced the carbs. The problem is when starting it. It seems to only want to catch(start running on the left 2 cylinders and slowly catch up after a minute or two and run right on all four cylinders. If I choke it it will not even hit on the first two cyl. so when I try to crank it I have to keep the starter button pressed as it is hitting on just the left two cyl. till it can run on its own. After it gets warmed up it runs like a top, smooth and even, no surging or missing. While it is still warm it will crank with barely a touch of the starter button. Can someone point me in the right direction. Thanks.

Steve E..........

[tkent02]

Adjust the intake and exhaust valve clearances.

[Steve]

Ditto.

.

[se3388]

I'll get my Haynes out and get to it. Thanks guys.

Steve E..........

[spyug]

Welcome aboard and do as he says.

Actually there are several threads recently on this. When a bike is hard to get started there are 3 things that are always suggested. In Order of precedence:

1) adjust valves
2) throughly clean carbs and fit new o-rings

These usually fix the issue but if still not easy to fire:

3) change plugs and perform the "coil relay" modification.

Our buddy and official greeter BassCliff will be along shortly with his mega welcome which provides links to all of these little tune up jobs.

Take care of these and you will have a reliable starting and enjoyable ride.

Good luck with it and please post some pics.

cheers,
Spyug

[BassCliff]

Greetings and Salutations!!

Hi Mr. se3388,

Here's how we show our bike some lovin', with some proper maintenance and few fresh, new parts. It's all in your "mega-welcome".

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[se3388]

If I read how to do this right it seems that I measure the exhaust valve clearance with the exhaust cam lobe point horizontal, if so a feeler gauge .002 (.05 mm) would not fit but a gauge of .0015 (.04 mm) would just fit. I measured the intake valve clearance with the intake cam lobe point straight up and it measured the same as the exhaust clearance.
If all this is right does it mean that I need to install a shim with the thickness of about .004 or .005 to bring it up to around .007. Thanks for any help.

Steve E.............

[tkent02]

Stick with metric numbers or we will get all goofed up. The spec in the book is .03mm to .08, most of us use .10 as the upper limit. If it is .04mm or larger, it's tight but near the limit, so it's OK to run it while you look for the next size smaller shim, which will be .05 smaller than the one you have now, and will bring the clearance to .09mm. Loose is better than tight, err on the loose side if you have to err at all. For instance if you have a 2.65mm shim in there now, a 2.60mm will bring your clearance to .09mm. If the clearance on all of the valves are at least .04mm you are OK to run it. Usually on a new to me bike, several of them are too tight, one or two is loose, a couple might be OK. It's the tight ones which cause the hard starting and burnt valves.

[se3388]

Most are .260 with at least one .260X (which I think is just a large .260) and one going .270.
So it appears to me that I should go with a .255 for the .260 and 260X and a .265 for the .270. Hopefully I'm getting this straight. LOL.

Steve E..............

[tkent02]

So all of your valves were around .04mm or so clearance? That's amazing, a PO must have actually done some maintenance. I didn't know that ever happened.

[se3388]

So does it sound like I have the positioning of the cam lobes down right? If so and my measurements are correct then should I open them up to .08 or so?

Steve E.............

[tkent02]

If they are all really .04mm or better, just run it a while as is. Check it again in a little while.

[se3388]

World of Wonders, I opened the clearance on the valves up to the next size and that thing starts quicker than I do, LOL. It is a pleasure to start now. Thanks BassCliff and all the others that offered advice.

Steve E..............