Carb Tuning Questions

racerman_27410 · April 09, 2009, 08:19:47 PM

well the rubber carb joints are what 20 years old? and i'm positive the o-rings that seal them to the head are completely flat by now..... i dunno.... there "might" be an issue there

drawkward · April 09, 2009, 08:36:28 PM

Haha....

Ya I just took them off. The o-rings are flatter than a six year old (is that joke considered taboo? If so, accept my apologies) and the part that seals around the carbs are cracked to shit.

Anyone know if someone has them cheaper than 100 bills?

http://cgi.ebay.com/ebaymotors/YAMAHA-FJ1100-FJ1200-CARB-HOLDERS_W0QQcmdZViewItemQQcategoryZ35597QQihZ023QQitemZ360145898632

Harvy · April 10, 2009, 05:56:46 PM

Jon, I got my replacements from Georgefix (that guy on ebay).......could not find them anywhere else at the time so can't really comment on the price, but can tell you that those are good quality and well made. OH, and if you have a Japanese home market import model, the OEM throats are only 28mm, whereas these are the full 32mm deal.

Harvy

drawkward · April 10, 2009, 07:35:11 PM

Quote from: Harvy on April 10, 2009, 05:56:46 PM
OH, and if you have a Japanese home market import model, the OEM throats are only 28mm, whereas these are the full 32mm deal.
Harvy

Hell, I have no idea which model my bike is...I just bought them too. I guess I can just hope that they're the right size!!

racerman_27410 · April 10, 2009, 09:07:10 PM

those carb joints will work just fine...... nice price on them.

racerrad8 · April 14, 2009, 05:12:08 PM

FYI, I can get carb manifolds for $100.00.

Randy - RPM

drawkward · April 14, 2009, 05:57:54 PM

Quote from: racerrad8 on April 14, 2009, 05:12:08 PM
FYI, I can get carb manifolds for $100.00.

Randy - RPM

Thanks Randy, but I just got them in the mail today. Only cost about $100 from ebay so I guess that's not too bad. It seems that's the going price for them...which seems a little on the high end, but whatever.

I'll update tonight to let you guys know tonight if they solved my problem.

drawkward · April 14, 2009, 08:10:11 PM

So, I got the carbs back on the bike. It's running noticeably better and I believe the vacuum problem is resolved. However, it still has a little bit of a hesitation when blipping and the idle is still a little south of 1000RPMs even with the idle screws and set to where I believe they need to be.

So, in my estimation, I think the carbs are still going to need a bit of work. The bike makes all kinds of power above that 1500 to 2000 RPM mark and is fast as hell, but I feel if I want to complete this thing and eventually if I want to sell it, the issue at idle needs to be resolved. I am thinking of maybe rebuilding the carbs completely and getting some new jets, but I'll have to do some more research or maybe even take it to a Yamaha or import guy to have it checked out...but that makes my stomach upset to say the least

All in good time.

I owe you all a beer or two, so if you're in Houston, let me know!!

racerman_27410 · April 14, 2009, 08:14:37 PM

the hesitation can be tuned out using the idle mix screws....

you have synched the carbs on the bike?

drawkward · April 14, 2009, 11:24:08 PM

I haven't yet synced the carbs on the bike yet. I made a carb sync tool, but the bike just froths the oil up when I hook it up. I need to put restrictors in the lines and it might work...but I should probably just buy the damn professional tool.

Do you think a carb syn would get rid of that problem? I have tried messing with the idle mixture screws a ton but can't seem to get rid of the hesitation. I think I am currently 3.25 turns out, and that's where I found the best idle. I started at 2.5 and worked up by .25 turns each time. I never went below 2.5 turns though...

Marsh White · April 15, 2009, 12:01:24 AM

Dude, this makes me think you didn't pay ANY attention to my previous post in this topic...back on page 1. I put a bit of work into it for you...read it...do it. It will solve your problem...I also addressed your carb sync tool...scrap it and do what I said...you don't need to pay for a "professional" tool. But...whatever...

racerman_27410 · April 15, 2009, 10:18:43 AM

Quote from: drawkward on April 14, 2009, 11:24:08 PM
I haven't yet synced the carbs on the bike yet.

nothing you do is going to work without synching the carbs on the bike..... and 3.25 turns on the mix screws is too much

you cannot skip step one and go directly to step two.... it doesn't work like that.

drawkward · April 15, 2009, 01:59:44 PM

Quote from: Marsh White on April 15, 2009, 12:01:24 AM
Dude, this makes me think you didn't pay ANY attention to my previous post in this topic...back on page 1. I put a bit of work into it for you...read it...do it. It will solve your problem...I also addressed your carb sync tool...scrap it and do what I said...you don't need to pay for a "professional" tool. But...whatever...

I feel like I'm in grade school getting yelled at by one of the Nuns.

I planned on doing the carb sync as soon as I can figure out what the hell to use as a vacuum arrestor because I can't find line that small. As I said in my previous post, the "carbs are still going to need a bit of work" which includes syncing them. I didn't even ask for any more advice in that post, not that I don't welcome it always from all of you guys, cause I do for sure. If my posting updates on my bike and the small struggle I am having with it bothers you, don't read them.

rlucas · April 15, 2009, 02:35:00 PM

You may be able to find the restrictors you need at...believe it or not...a pet store that sells aquarium supplies.

Rossi

drawkward · April 15, 2009, 03:04:39 PM

Quote from: rlucas on April 15, 2009, 02:35:00 PM
You may be able to find the restrictors you need at...believe it or not...a pet store that sells aquarium supplies.

Rossi

Ahhh. I never thought of that. I went to the ACE by my house, which typically has enough of a selection to be able to build your own steam powered time machine, but I couldn't find any. Thanks for the heads up!!

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Carb Tuning Questions