given up on adjustment, where the heck are Jet adjustments?

Ok, I dont know enough to do this. Breaking down and paying someone to sync carbs.

I would like to try 1 more thing... I have read that adjusting the slow jets to dump more fuel can help. I know I am running lean beacuse I get tons of backfire.


1. Where the heck are the adjustments?
2. Any pics?
3. After removing the airbox and screen, what else needs to come off? If anything.

I wish it was as simple as turning a screw 1/2 turn without taking anything apart but I doubt it...

Thanks, and remember I am a newb...


Philly

 

Hey Newbie,

First piece of advice: get a manual. I haven't work on 1gen carbs but typically you need a special tool to turn the d-shaped screw. Sometimes they are capped to prevent folks from messing with them (EPA regs).

You'll need the manual for the sync procedure as well.

Good luck.

 

You are referring to the "Pilot" jets. They are sometimes called "Air" jets because they usually regulate the amount of air into the carbs. The Honda V4's pilot jets regulate fuel not air.

Turning the pilot jet in reduces the fuel, while turning the pilot jet out increases the fuel. Pilot jet adjustment is done after the carbs are synced.

Adjusting the pilot jets to stock settings and ride. If you still experience popping on deceleration, turn the pilot jets out 1/4 turn.

The pilot jet is shown in this article: http://users.rcn.com/kochc/moto/carb/carb.html
Look for "Pilot Needle Assembly"

 

Thanks so much everyone!

 

Forgot to mention, keep turning the screws out 1/4 turn until the popping goes away. I believe 5 out is the max number of turns you can go without the jet falling out.

 

How many screws 4?

 

Yes, one on each carb.

 

I found a good mechanic who is willing to do some side work. He will clean the carbs and re-jet for only $150! It will take 3-4 days but is worth the price.

For an 86 VFR 700 what jets should I use for stage 1
Should I use a carb tune-up kit?

http://www.factorypro.com/products/carb.html

 

You only need to rejet if you change both the air filter and the full exhaust sytem. Otherwise stick with stock.

 

ok..


The goal is to gain more performance.. Wouldn't a stage 1 help that out regardless of exhaust or airfilter (new uni)? I thought it would be a good idea while everything was apart.


What else would you suggest?

 

Actually, a stage 1 jet kit can possibly hurt your performance by making the bike too rich.

I suggest getting your bike in a running - highly tuned status. Then run it on a dyno so you have a starting point.

If you're dead set for getting a stage 1 jet kit, then by all means get it. Install it, tune the bike up again and run it on the dyno. Compare to the stock dyno.

Install a K&N air filter and run the bike again on the dyno. Compare

Install an aftermarket FULL exhaust system (if you can find one) and run the bike again on the dyno. Compare

Get to a library and read about engine performance modifications. There are books and books about it. It's much more than just slapping on a jet kit to get better performance. Honda has spent millions of dollars testing and designing the bikes before they go into production. It's pretty hard to improve dramatically from stock performance without lots of $ and time.

 

agree.. I actually modified my car pretty heavily with intake, ehaust, and intercooler.. Just dont know carbs.


Funny, I just realized I have a slipon exhaust! Cobra F1.. I thought I had stock... I am such a newb...

With slipons I dont believe I need a jet kit. At least according to your post above.

Stock/tuned it is...

 

I completely agree. The majority of backpressure is from the common collector under the bike. Unless you replace this, a slip-on will have minimal impact.

If you have a flat spot that seems to appear around 4-6 rpm (where the EPA tests emissions), it can be corrected by raising the needles slightly, which results in more gas when the slides are partially open. Install a 2mm washer (#4 electronic washer) under the piston slide needle.

 

So turning the jet screws out is not the same as raising?

 

Yes it is the same. But I believe the washer shims will affect it more - I am not sure. I put the washer shims in my V45 Magna and it did help with the flat spot- constant acceleration up to the red...

My 'Ceptor doesn't have that flat spot so I didn't install the shims. I did turn the jet screws in to lean out my mixture as I was getting popping on decel and I could smell the exhaust was rich (I upped the jets because I have K&N plus Kerker 4-1).

 

NEWSFLASH>>>>>> MESS IN CARBS MAKES MESS IN PANTS


So the mechanic found a mess in the carbs... He is charging the same price so I no its for real.

The low speed jets were completely clogged. He said 2 other jets were loose and not even really attached so I potentially was running on 2 cylinders (this is my opinion)
He was surprised the bike even ran. Said the carbs needed a ton of cleaning and a good sync.


With that said, I am so psyched. I bet the bike will completely change. Being my first bike I had no idea what to expect. I thought it was a complete dog down low, and I could not understand how the bike was a winner out of the box in 86. I thought we just have made that much progress over the years. But you look at an old vette and it can still hang, the forums had me so confused with people even attempting to hang with a 600. I thought, no freaking way even with a turbo kit. Not that I expect to hang with a new 600, but to even be close will be a MAJOR improvement.

So anyway, very excited to get everything back... Cant wait to ride my "new bike" (hence the mess in pants title)

 

Go slow and be prepared. There is a slingshot affect when the bike hits 6-7K rpm. If you go WO and hit 6-7K be prepared to shift very soon as it will hit the red zone very, very quickly. This is where most riders get into trouble. The increase in acceleration surprises them and they don't plan/look/prepare far enough in advance for where the bike is going.

I rarely hit 7K, unless I'm accelerating up an on-ramp or running 80mph. I may be old, but over 7k rpm in any gear past 1st on the street is too fast for me to react to cars turning in front of me.

 

Seriously? I used to hit 11k all the time before the carb fix.


OH BOY!!!!!!

 

Well.. I picked the bike up this weekend. No words can describe the pure joy and excitement. This is a completely different bike. Crazy fast...

I can hit 60 in the blink of an eye now. The front tire comes up with the twist of the throttle. The mechanic claimed his test ride was around 130 MPH...

I can now see why this was a winner out of the box. I love my bike.. I see zero need for a more powerful bike.

With only 18k miles on the odometer, I have to say the bike is performing like new.