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Greetings---
Live in Stowe VT, have a 1991 CB 750SC and want to clean and synchronize carbs. Looking for help, and prefer not to go to a shop. Anyone interested in this job?
Thanks,
Tim
Umm... I can clean em but without a sync tool my syncing is kinda as close as i can get em without a tool...
Live in Burlington and I don't know when I can get to Stowe. Are the carbs off the bike?
"I'd rather ride a slow bike fast than a fast bike slow"
Bikes: Ducati: 748 (Track) Honda: RC31 (Race/street)/ CRF 110 Mini Moto/ Hawk Endurance Racer Kawasaki: ZXR1200R
BOMO Instructor
EX# X
If you don't have a sync tool available, here is an old school method that isn't as accurate, but should make sure you aren't out in left field. With the carbs off, use some manner of small pin as a feeler gage. Turn your idle screw enough so that you can get that pin under one of the throttle plates and the carb body. Adjust the idle screw so you have a light drag. Now, make sure the three other plates have the same drag. On a typical OEM carbed bike like yours, you have three adjustment screws. One between carbs one and two, one between three and four,,,, and one between two and three. I wrote it in that order on purpose. The screws between 1-2, and 3-4 are to adjust those pairs to each other. The screw between 2-3 is to bring the pairs together. This method doesn't take into account differences in flow rate, or compression/leak down in each cylinder, but may catch any gross mismatches. You'll hear those mismatches anyways. Once you have done a thorough cleaning, if the engine idles smoothly at about 1000-1100 rpm, chances are pretty good that your carbs aren't out very far, if at all.
The bike has a Stage 1 jet kit with the loudest Vance & Hines pipe I have ever heard on a Nighthawk 750
Mmm looks like we need to find a synch tool.![]()
TIMMYDUCK
Carbs are not off bike, but I can get a sync tool...
Sounds good...would love to get it done somewhat locally. I could probably wait until riding season, and cruise it to someone's garage. Keep me posted...
What about a DIY manometer? They're easy enough to make.
...and Doc, please just stop.
We could do it in the pits @ the track, in the spring Tonner........just like we did your ft.end........
how are the forks Btw.??
Make sure you get a gasket kit in the meantime.
Last edited by fivetoez; 03-03-10 at 07:56 PM.
I miss ya Beet....ya Git!
That's a kind offer, as long as it's not an imposition, and I'll bring the Drake's coffee cakes...