well, i was going to sync the carbs on my hurricane.. and i was just wondering what rpm this should be done at I've heard that it should be done at idle, and I've also heard it should be done a 1/4 to 1/3rd of beak tq RPM.. anyone have any info?

thanks in advance

 

I had questions for a long time when i had my 89 Hurricane..i gave up all reasoning and took it to the Pros at Honda...it was a lil pricey but better than i ever would of done on my best day.They Sync'd and cleaned and replaced and tightned. I had 25k on the bike the day i sold it and it ran strong enuff that the buyer asked me if i really wanted to sell it..Sometimes taking it to the Stealer for service isnt a bad thing.....Just my 2 cents.

 

I think the problem here isn't htat i'm not capable of doing it,, it's just that i need a little more info, and the haynes manual says diddly squat about it

 

Synching the carbs is basically just to make sure the bike starts up and idles well so you always synch at idle. Make sure you mainain the same idle rpms as you adjust each carb for best results. Synching has no affect on midrange or high rpms.

 

thank you

now i'll post my setup for cheap carb syncing

what I used to sync my carbs was a good 4 foot length of silicon tubing, a Tee fitting to fit, a glass bottle (600 ml- 1000 ml), and an ordinary engine vacuum guage.. I also had a small restrictor that fit inside the Tee to reduce pulsation

connect one end of hose to carb #2 (the one that's directly connected to the throttle cable) cut the hose to give yourself a comfortable length to work with, connect to one side of the Tee, port #2 of the tee should be drilled and sealed onto the cork/cap of the bottle, while the 3rd port connects to your vacuum guage. I had the restrictor on the side of the Tee facing the carb

this should provide you with a nice stable vacuum reading, I found it took about 5 seconds for it to build up the vacuum.. as they say, it's not important what the exact number is, just that all cylinders are the same.. just note what the reading is on carb #2 to start

then switch the vacuum line to carb #1, and adjust it to match, or near match.. the engine speed will fluctuate, and that will change the reading of cylinder #2, so you will have to go back and forth probably about 3 times until they are both identical.. you may also have to adjust the idle stop to keep it running. Then do cylinder #3 in reference to #2... then do #4 also in reference to #2.. when you're all done, just go through them all and make sure they are all the same.. you should be pretty close...

you can use a CHEAP vacuum guage to do this, as long as it is sensitive.. remember it doens't matter how accurate the scale itself it.. just that all cylinders read the same

this setup would cost me about 15$ if I had to buy everything new.. I had everything laying around already. it takes a little longer, but I can't justify 100$ on a tool that I'll hardly ever use

 

Synching has no affect on midrange or high rpms.

Are you sure about that? Synching the carbs on my bike cured not only rough idle, but cleared up rattling noises and rough running at mid-range and higher, gave cleaner throttle response and in general made it a much better running bike.

 

well.. I think there's some fuzzy language here.. it makes no differance at mid to full THROTTLE, now if oyu're cruising at 5000 RPM, but only 10% throttle, I think it DOES make a differance

 

Ed Zachary It generally won't have any affect on throttle positions over 5%. It will help with crisper throttle response off idle -- and when you let off the throttle to change gears you're feeling some positive effects from the carbs being in synch also.

 

Just out of curiosity, you mind if I ask how much the dealer charged for doing your carbs?

 

i took mine to a shop $300 for the carbs to be cleaned with includes a resync. but unfortunately they are still not working properly, so back to the shop she will go!