choke "works" for 5 seconds, then kills engine

[Earthling789]

I agree, something is strange with the statement that your choke/enrichment is either ON or OFF... the enrichment valve should travel, based on how much you move the lever. Fully OFF, means lever is all the way forward, which allows the enrichment valve to seat against the carb. Fully ON (lever down or towards you), lifts the enrichment valve, allowing more fuel to be passed.... at least that's the basics, anyway...

Checking your choke/enrichment is simple enough... just disconnect one side from the carb and move the lever... see if the little valve moves up and down. Then check the other side for the same action. While they are disconnected, you can also check to see if they have the correct gap/free-play... move the lever all the way down (fully closed position) and measure from the bottom edge of the threads of the cable, to the upper edge of the main cylinder shape of the valve (upper shoulder of the valve). this gap should be 10-11mm, if memory serves correct... adjustment is made at the cable connection below choke housing.

[Dauntae]

Originally Posted by flivver

Interesting... Due to the magic (and temptation) of Amazon Prime, I have a set of four arriving on Tuesday.

Good buy, Mine had a little trouble in the colder weather but not bad but since the bike was new to me at that point I too got the Iridium plugs and it started so much easier.

Earthling789
He has the 750 and it's only the VT1100 that has that cool choke lever I think LOL But I agree with your post, Just that it's in or out and not forward or back on the 750's.

Dauntae

[flivver]

Originally Posted by Earthling789

Checking your choke/enrichment is simple enough... just disconnect one side from the carb and move the lever... see if the little valve moves up and down. Then check the other side for the same action. While they are disconnected, you can also check to see if they have the correct gap/free-play... move the lever all the way down (fully closed position) and measure from the bottom edge of the threads of the cable, to the upper edge of the main cylinder shape of the valve (upper shoulder of the valve). this gap should be 10-11mm, if memory serves correct... adjustment is made at the cable connection below choke housing.

Can this be done without removing the carbs? My recollection is that none of the important bits are visible from the exterior...

If I have to remove the carbs, I think I'll just live with hard starting in cold weather. Getting the carbs back on last time was a difficult process (for me, anyway)...

[Earthling789]

Yes, they can be checked and adjusted without removing the carbs... the enrichment valve is attached to the choke cable and just "plugs into the carbs" one on each side. I'll see if I can find a picture for you, but they should be easy to find... just look for the black cable boot going into the side of each carb. The little nut that tightens them into the carb opening is plastic, so be careful not to tear them up as you loosen them for removal.

Not the best picture, but this will give you an idea: Enrichment valve being removed from carburetor

[93gc40]

Originally Posted by flivver

Hmmmmmm. I guess I've been using it wrong. I've been pulling the choke on (fully), then starting the engine...

Just talked to a buddy over lunch, who suggested that I may need to enrich my mixture by tweaking the pilot screw on each carb. That sound plausible?

You using the lever as an ON/OFF switch or as a variable valve it is designed as? Could be you are just being too extreme. You only need use the amount of choke required to maintain steady idle when cold. The amount could be anywhere between the off (closed) setting up to ON or full open, and can last from 3o seconds to 5 minutes. And can require adjustment during the warmup process. Fact is if you are not using at least partial choke for first of the day starts of the day at temps below 70 degrees, you probably need to adjust the AF mix and choke anyway.

[flivver]

Originally Posted by Earthling789

Yes, they can be checked and adjusted without removing the carbs...

Will have to give that a look tomorrow... Thanks for the picture!

Originally Posted by 93gc40

You using the lever as an ON/OFF switch or as a variable valve it is designed as? Could be you are just being too extreme. You only need use the amount of choke required to maintain steady idle when cold. The amount could be anywhere between the off (closed) setting up to ON or full open, and can last from 3o seconds to 5 minutes. And can require adjustment during the warmup process. Fact is if you are not using at least partial choke for first of the day starts of the day at temps below 70 degrees, you probably need to adjust the AF mix and choke anyway.

Well, I think I'm using it as an on/off switch out of necessity... As in, if it's in any positive except full-on, it has no effect at all; at full-on, it behaves as I've described. I imagine my AF mix does need to be adjusted. Is it as simple as removing the plug over the pilot screw and turning the screw in small amounts?

With respect to the spark plug recommendation, I installed the NGK DPR8EIX-9 (iridium) plugs tonight. The bike had been idle in a cool garage for five hours prior to the switch. When I went to fire it up, it fired right up and immediately idled a bit higher than it normally does (after sitting for hours). The morning will be the real test, I guess, but the plugs look promising...

[Dauntae]

There great plugs and helped with my cold weather starts but I didn't have the issues your having. Let us know how it goes tomorrow.

Dauntae

[flivver]

Originally Posted by Earthling789

Yes, they can be checked and adjusted without removing the carbs... the enrichment valve is attached to the choke cable and just "plugs into the carbs" one on each side. I'll see if I can find a picture for you, but they should be easy to find... just look for the black cable boot going into the side of each carb. The little nut that tightens them into the carb opening is plastic, so be careful not to tear them up as you loosen them for removal.

Not the best picture, but this will give you an idea: Enrichment valve being removed from carburetor

So I got down to where I could have removed the cable from the carb (i.e. I removed the air filter cover, the air filter, and the various bits shrouds that cover everything), but wasn't sure what I was going to accomplish by removing the cable from the carb. Sorry to be dense. Basically, all that would have been visible is the exterior of the carbs, and the small hole where the cable goes in. Would I be able to see a valve through those small holes?

With respect to the plugs, looks like they didn't help as much as I'd hoped. After sitting all night in a cold garage, the bike started (as always) but barely stayed running (which is what normally happens). Adding choke produced the same results that it used to. I think it runs a little better once its warm, but that's about it.

As I was looking through my Clymer today, I noticed that the VT750DC model has a carb warmer... The VT750C (which I have) does not. Maybe Honda foresaw this problem, but only equipped certain trim lines appropriately?

[John Hopkins]

Originally Posted by flivver

So I got down to where I could have removed the cable from the carb (i.e. I removed the air filter cover, the air filter, and the various bits shrouds that cover everything), but wasn't sure what I was going to accomplish by removing the cable from the carb. Sorry to be dense. Basically, all that would have been visible is the exterior of the carbs, and the small hole where the cable goes in. Would I be able to see a valve through those small holes?

With respect to the plugs, looks like they didn't help as much as I'd hoped. After sitting all night in a cold garage, the bike started (as always) but barely stayed running (which is what normally happens). Adding choke produced the same results that it used to. I think it runs a little better once its warm, but that's about it.

As I was looking through my Clymer today, I noticed that the VT750DC model has a carb warmer... The VT750C (which I have) does not. Maybe Honda foresaw this problem, but only equipped certain trim lines appropriately?

By taking the 'choke' cable off you are not just removing a cable you are removing a whole valve assembly consisting of the starting enrichment valve, the spring and the locknut on each side.

John.

[Scrapdog2grand]

You had metioned the last time you tried to get the carb s on was a pain in the a55. Why did you take them off, for cleaning? did the bike sit, you may have a dirty or glogged cold start enrichment circuit in the carb, one of the tougher passages to get cleaned properly in my opinion.

are you sure the cables are routed properly? if unsure, the front carb cable comes over the carbs to the left side then joins the rear carb, they then go around the top of the carbs out the right side and then under and back to the left side.