88 Suzuki GSX-R750

[Lord Jebus]

I bought an 88 GSX-R750 off the guy down the street from me about a year ago. I was the last person to ride the bike before it was stored in the garage for about 8 months before I bought it off him. I was the one that parked it and it ran great but I figured he was gonna use some fuel stabilizer when he stored it. Sadly he didn't. So when we pulled it back out I had a really hard time starting it... It needed a new battery and I gave it an oil change but it still took me about 45 minutes to get it to start. When it did it would idle but ran rough and had a bad hesitation when I gave it gas - not like it was bogging but rather it was just a 1-2 second delay in throttle response. I figured the carbs were blocked but before I touched them I wanted to eliminate a problem with spark. I replaced the plugs and plug wires. Then when it still ran rough I discovered the coils were weak so I replaced them. Still I had the same problem. So I finally decided to rebuild the carbs. After cleaning them and replacing o-rings and checking the diaphrams I reinstalled the carbs. Now it has a great response but won't idle without the choke. I've tried adjusting the idle screws on each of the carbs and the main throttle screw on the bottom of the carbs without any improvement. Can someone tell me if I've missed something? I figure it's running lean because it will idle with the choke on. Or maybe I have a vacuum leak which is leaning it out. I'm at the end of my rope with it. And I'd rather not send it out to be fixed...

Second - I want to replace the tail light and signal markers with some custom made LED's. I have the abililty to make so pretty trick stuff out of Fibreglass and plastic and I can easily get LED's and Resistors and have a basic understanding of electronics. Problem is I need to make the signals flash and since LED's have no load compared to incandesant bulbs I need to add resistors and such. But where do I start is there a formula for the amount of resistance needed per LED? Or is there a diagram somewhere for me to use as a guide? I've tried to do my research but have come up empty so far. Any help would be much appreciated.

Thanks!

[SMcLaughlin]

Almost sure that your pilot jets or the pilot circuit is restricted. When you had the carbs apart did you remove the idle fuels screw? They are tiny brass flat head screw located under the carb body toward the front of your carbs. They have a small spring, washer and o-ring on them. Pull these out and clean out passage way with good cleaner, best to do this with the pilot jets removed to make sure that the passage is clear. These should be set at about 2.5 turns out from lightly seated in the carb. Also make sure that the vacuum slide diaphrams are in and not pinched by the carb cap, the cut out in the bottom of the slide points toward the airbox. If memory serves me, the carb caps have rubber plugs over the sync, ports. Make sure that the small o-ring is under the carb caps and that one the the carbs supply vacuum to your fuel valve. I believe it was the #3 carb that provides vacuum to the fuel valve. Make sure that the local wildlife has not made a new home on your airbox. Getting the filter out is a real pain on that bike as you have to remove the battery and battery box to do it.


I had a 1986, 1989, 1991, 1994 and a 1996 GSXR-750 and loved everyone of them. Would like to find another older 90's GSXR someday. Good luck and keep us posted on your findings.
-Sean

[Lord Jebus]

Yeah I had the pilot jets out and made sure they are squeaky clean. as for the idle fuel screws I had tem all out except one and they were the screws on the bottm of the carbs that I mentioned I was playing with that made no difference. The one that wouldn't come out I accidently stripped the screw head slightly cuz it insisted it didn't was to move at all... I even soaked it in paint thinner still wouldn't budge.... I figured I'd be able to get it to idle on 3 carbs though. I'm almost at the point where I'm ready to buy new carbs.

[Lord Jebus]

AS for keeping you updated... I will definitly do that... it just won't be for a few week until I get to work on it again. I'm moving from Toronto to Vancouver in a few weeks. It's getting packed up with the rest of my stuff.

Thanks for the help so far though

[Desy2820]

thought it might help.

http://www.lsdiodes.com/tutorial/

Here is a calculator for resistor sizes:

http://metku.net/index.html?sect=view&n=1&path=mods/ledcalc/index_eng

As to a blinker, have you looked at getting an electronic one used in cars from a junkyard?

Hope this helps!