Anti-Freeze leak

[Oldbikefixr]

Got the carbs off. Pretty easy with a broom stick. Thanks to everyone for your advice. I'd feel better if I had any clue what I was doing. Lol

Take photos as you go. Organize the parts you remove onto a workbench....or the floor. A Honda repair manual will certainly help. Photos of the job can be found using the 'Search' function top right of the page. Just search on ST1100 Carb Removal or some variation.

 

[PmodelinUS]

So far I found a bit of leakage on one hose but nothing that looks like it was leaking that much. Definitely wet under all the hoses though.

 

[dwalby]

So far I found a bit of leakage on one hose but nothing that looks like it was leaking that much. Definitely wet under all the hoses though.

FWIW, if it turns out in the end that this wasn't the cause of your leak, don't consider it a waste of time. Those hoses swell over time and are known to strand riders after they fail, so replacing them and knowing their age/condition is a big plus in being confident to take the bike on a long trip.

When you re-install the carbs, be patient, getting them to slide back into the new carb boots is a bit of a pain. I never figured out what I did differently when they finally popped back in, but it took a lot of tries to get them to seat.

 

[JJames]

If you feel you didn't find the leak , you might want to check the over flow tank (it probably needs a clean to see the level anyway) and the hose that goes in it . It runs on the right side . I can't think of anything else on the right side, on the back of the engine . The US spec ST has a few more hoses/lines than mine , but I kind of doubt ,they have coolant in them - might be wrong ! . In the front of the engine ,right side is thermostat housing - Kind of made of the same alu as the elbows -that could leak - and radiator.
Getting the carbs back in place : Think the trick is - lay the carbs down on the well lubricated (warm) rubber manifolds . Make sure ALL 4 carbs starting to enter inside the rubber manifolds - they will enter at an angel /not flush . Give the carbs a good push strait down - they will pop right in.
Good luck !

 

[Oldbikefixr]

That overflow line from the thermostat housing to the overflow bottle was a leaker on my 1991, one of the first parts I replaced. The o-ring was dripping a bit, the filler cap seal was cracked up and all the water hose connections were badly corroded. Those would drip on the right side, probably onto the top of the engine if you were moving along. The oil filter mount is water cooled, with two hoses running between the mount and to connections behind the left side headers high up between the left two cylinders. Again, a leak at the top connections could spill into the valley of the engine under the carbs. Could be the o-rings between one of the right angled water fittings and the engine.
I'm preparing myself to go leak hunting on my 1991 when yard work eases up a bit, even though I replaced all the hoses just a year and a half back. It's a little one, leaving a small puddle under the front of the engine after a ride. It begins when the engine is warm. A quick look with a flashlight shows nothing. More fun in the workshop.

 

[Bush]

Am I losing my mind, or what?? The OP says he has no PAIR on his '93, but there sure is a lot more plumbing down in the bottom of that V than I saw in my non PAIR '95 when I did the coolant hoses.

The valley bottom on mine was virtually bare except for where the "water pipe" from the front of the engine came in and attached onto the crankcase area. What gives?

 

[Sunday Rider]

Looks like the PAIR system is still there.

 

[KSRider11]

I have had the carburetors of my 91 off several times in the 24 years that I have ridden and wrenched on it. The method of installing them that I use this:
1. Put a light film of petroleum jelly on the inside lips of the carb boots/mounts/insulators/whatever.
2. Place the carb set loosly in the "v" of the cylinders so that they can be angled to allow you to attatch the throttle cables FIRST. You'll see why when the carbs are seated.
3. Set the carbs on the mounts with the LEFT carbs tucked down into the mounts and the right carbs touching and aligned with their mounts.
4. Lay a short piece of 2x4 across the right side of the aluminum plenum, parallel with the wheels/frame, and while pressing firmly on the left carbs, give the 2x4 a smart smack with a medium to large rubber mallet and the entire carb assembly will pop right in.
5. Use a flashlight to make sure that the aluminum bosses cast on the carb spigots are seated firmly against the carb mounts. Use more applications of 2x4/mallet as needed to fully seat carbs on both sides
6. Before tightening carb mount clamps, check to see that the enrichment actuation assemblies are free moving and can completely close. I have installed one of those clamps with the screw on the wrong side of the mount and it prevented full closure of the enrichment plungers on that side of the carb set. I have painted the heads of the carb mount screws a florescent green to make them easier to locate for future carb surgery.
I hope that this is helpful to anyone who is struggling to seat the carbs by attempting to engage all four carbs at the same time. I could never do it but YMMV.

 

[PmodelinUS]

Ok so what is all the plumbing under the carbs. See pic. Also what are these chrome tubs? I cannot find a pic of these in my manual. I'm guessing California. Emissions crap.

 

[Ron]

Ok so what is all the plumbing under the carbs. See pic. Also what are these chrome tubes? I cannot find a pic of these in my manual. I'm guessing California. Emissions crap.

Chrome tubes are part of the PAIR system. The PAIR system has been removed by several owners. It's a anti-pollution system.

 

[Ron]

PAIR=pulse secondary air injection system. Don't know how they got PAIR out of that other than "Pulse Air". Fresh filtered air is drawn into the exhaust port. The air helps burn the exhaust gases and turns them into carbon dioxide and water vapor. (paraphrased from Honda Service manual)

 

[PmodelinUS]

Again, thank you to everyone for your your help. After reading several posts on this I decided to go with plates to cover up the removed PAIR plumbing. I was searching and found a seller offering premade plates. I will let you know how that goes once I get them. If anyone is interested here is the link.

1993-2003 Honda ST1100 Secondary Air Injection System Cover | eBay

4-B Plates. Only basic hand tools are required.

www.ebay.com

Again I want to say thank you to everyone on here for your help and knowledge.

Brian

 

[PmodelinUS]

Finally got all my parts in and got brave enough to take off all the PAIR plumbing. Aside from the remains of a mouse nest under it i also had a nice pile of wet goo. Looks lie a few hoses were leaking but nothing exploded just bloated

 

[PmodelinUS]

So after a few weeks and lots of crappy weather I finally got the beast running. Only missed one vaccum hose. Otherwise all is good. No to put the body back on. Lol

 

[Smudgemo]

Before you put the platic back on, check that the enrichener linkage is situated correctly. I put mine in backward, or somehow incorrectly and it fouled the throttle action. I activated the enrichener, and worked the throttle where it forced its way past the linkage, but the idle raced because it wasn't able to return to the idle setting. Not sure if that makes sense, but just pull the enrichener lever and then make sure the throttle travel moves freely before you button it up. And don't despair if you smell some coolant. I did, but I was sure it was assembled correctly and either it was just spills burning off or things settled in and any tiny leaks stopped. Either way, it has been perfect since.