Carb Pods on a CB1100F....question..

MB-5 Joined: Sep 25, 2019 Posts: 4 Location: Northwest, IN

Hi All,

looking at a nice condition CB1100F that appears all stoock minus a 4 into exhaust and carb pods. The guy sent me a cold start video and it seemed to crank for what I would say was a longer then normal time before it started. Is this a typical thing with pods and the potetial lack of vacuum signal? Seemed to run and idle good.....just curious.

Do these 1100's run well with a pod and exhaust set up if jetted correctly?

thanks!

Posted: Sun Sep 29, 2019 4:26 pm

"Extended time to start" and "Cold blooded" are terms which are used to describe these bikes, especially if they have sat for a couple of weeks without running. Another topic of debate is the time required to start depends on the presence (or lack of...) the vacuum fuel valve (many of us remove the unnecessary valve and throw it as far as our old arm allows, other are advocates of the valve, and will insist you keep it...).

As far as the pod filters topic, debate here has been extensive and inconclusive. I have a 900 that runs great with pods and a 4 into 1 pipe, others will claim that a bike will barely run... A rabbit hole which will never be solved.

Welcome to the obsession, ride safely, sir.

MB-5 Joined: Sep 25, 2019 Posts: 4 Location: Northwest, IN

Thanks for that info. and it makes sense...especially the vaccum operated petcock which I forgot it would have, haha.

Posted: Sun Sep 29, 2019 10:20 pm

Buy it!
If he has not got the jetting sorted out you can start looking for an airbox.
otoh...Buy it!

Posted: Sun Sep 29, 2019 10:59 pm

See if this wrinkles the cranium somewhat:

1. There is an idiosyncrasy to a normally aspirated engine. Lawnmower, generator, mini bike, 4x4, etc. Find it.

2. There is a diaphragm fuel system that pumps fuel each time you open the throttle. It needs no vacuum because it is remote on its own. You jerk the throttle open enough times you will flood the engine. There is plenty of fuel to be sucked out of the bowl before a vac-assist petcock is needed. So the trick is to give so many throttle openings before you know how many squirts it takes to fire it right off. Start with 3 throttle pulls and leave the throttle grip alone. It wants to fire, 2 squirts, no touch but let it catch before you find out if it does not want throttle or will take throttle once it catches. Then if that's the idio for startup... that's how I'm going to guess at it. So say it takes 2 squirts, an ever so small a throttle opening and fires off. That's the idio of said exampled 'cold blooded' engine.

3. The revolutions continue with the kill off, so fuel still is being pulled into the port/valve/chamber with a closed throttle i.e., idle circuits. That un-fired fuel finds itself sitting in the port, in the carbon on the valve, on top of the piston dome, if not filling liquid in between the pores of the built-up carbon. Weeks later it evaporated = Hard starting. Why is it easy to start the next day then? That's my junk science guess at it.

4. The arm pitching parts away is not following thru with the engineering. That's if the engineering says on the petcock; I have no way of stopping the fuel but by the fuel float needles. The engineers found a convenient way of not turning the petcock on and off all these years. If it reads RES-ON-PRI, is that not 3 options excluding the OFF position? Therefore, I'd be checking my crankcase oil level before I'd fire it up. The oil runs off the dipstick like water? That's fuel contamination as in, no way to stop the flow from the source.

Make sense?

Signed,
NOLTT (no one listens to turtle)

Posted: Sun Sep 29, 2019 11:39 pm

cliffiec wrote:

As far as the pod filters topic, debate here has been extensive and inconclusive. I have a 900 that runs great with pods and a 4 into 1 pipe, others will claim that a bike will barely run... A rabbit hole which will never be solved.

I've been down that rabbit hole and found the answer under the hole. Stock ac box has a slit at the bottom for its air intake, yes? It's not huge, right? Looks like a restriction of air entering. The air cleaner is another restriction. The box holds so much air per square inside, yes? So I count 3 restriction variables.

Pod wise, it unrestricts the air. So nature like E is going to take the fastest path returning back from a negative pressure or say half of 14.7 psi for argument sake. So at this stage, can we say more air was easier to enter or less restricted is the modification? Of course. So the fastest path was less pull of fuel out of the metered holes. As a result it falls on its face i.e., less fuel entering. You jet it more and does not less air now enter filling that void? That void closes right at 0 or nature evened the vacuum back to atmosphere (14.7) says my medical vacuum gauge showing; 760mmHg (1 atm).

So if you follow my junk science you filled the ATMO with a proportion of a speed event of who is the fastest filling that void. More gas used, the bigger the bang of energy... it still closes @ 14.7 all back to nature. So if I kept the same jetting as stock, have the pods, an empty aluminum can I could cut a wrist band size strap and place it around the pod to close down the air speed event restriction wise. The wider the band the slower the air, the gas has a chance to equal back to box stock. So says junk science speak.

I'm in 'camp same volume' not 'more air.' If you think you are about to fight nature against a negative pressure? Have fun withatrick.

MB-5 Joined: Sep 25, 2019 Posts: 4 Location: Northwest, IN

Ummm...wow...lol Shocked

MB-5 Joined: Sep 25, 2019 Posts: 4 Location: Northwest, IN

smurdoch wrote:

Buy it!
If he has not got the jetting sorted out you can start looking for an airbox.
otoh...Buy it!

Leaning towards that! Smile

Posted: Mon Sep 30, 2019 6:48 pm

cliffiec wrote:

"Extended time to start" and "Cold blooded" are terms which are used to describe these bikes, especially if they have sat for a couple of weeks without running. Another topic of debate is the time required to start depends on the presence (or lack of...) the vacuum fuel valve (many of us remove the unnecessary valve and throw it as far as our old arm allows, other are advocates of the valve, and will insist you keep it...).

As far as the pod filters topic, debate here has been extensive and inconclusive. I have a 900 that runs great with pods and a 4 into 1 pipe, others will claim that a bike will barely run... A rabbit hole which will never be solved.

Welcome to the obsession, ride safely, sir.

I have pods as well. The only time I have issues is with a crosswind. Unfortunately down here, that's the nature of the beast. I won't go back to the stock box.

My 900 has sat for at least 3 weeks and starts right up every time. Now, it's a bit warmer down here, so that has something to do with it, I'm sure. However, if I go 4 weeks, for some reason, it takes about 3 times as long to start (which still isn't too bad.)

Posted: Sat Nov 02, 2019 12:51 pm

I like pods. Not so much from a performance aspect but from an ascetics point of view. Getting rid of the fugly airbox cleans up the back of the engine and makes the entire bike look better.

As far as the jetting goes on an 1100 the Canadians got the "stock" jetting right...... 40's on the "slow jet" instead of 38's on the emission restricted US models, which is why the Canadian bike seem faster (it's an illusion boys they just run correctly not faster!) Sudco ..... http://www.sudco.com/files/assets/basic-html/page-1.html .... has the jets you need NLA from Honda). The stock mains are 122's which are ok with stock exhaust but have to be increased to 124's with a pipe. I spoke with Mike Nixon regarding his recommendation to disable the "idle cut valves" on the sides of the carbs and he does NOT recommend it with an aftermarket pipe ..... I have had little or no success with carbs I have done for piped bikes and in with a couple 1100 it causes a weird mid-throttle surge. The 750 / 900 carbs have a completely different cut circuit and tolerate the mod much better.

If a prior owner installed a "performance" jetting kit start over with stock needles and jets. In my experience the Dynojet kits suck. Excessive fuel consumption with little or no performance advantage. The achilles heel on these motors is not the carbs or the fuel delivery ..... CR's (hard throttle pull) and FCR's open when throttle is requested and are a great upgrade but are are a bit violent for my tastes. The issue is the poor intake port shape combined with a bad combustion chamber design. Pipes help especially the Hindle or Chris Lee pipes because they pull the mixture into and out of the engine!

If you want to judge the jetting on your "properly running" bike(s) put the bike on the center stand and fill it until the liquid just touches the lower ring inside the tank filler neck then ride moderately to reserve and return to the same fuel station the same day (fuel density changes day to day / load to load in the storage tanks) and precisely fill the tank to the same level. 40 mpg to 45 is average to very good. This is assuming good maintenance correct compression and a smooth running engine (plugs / secondary ignition operation ect.) Most of the "F-er's" I ride with go 150+ miles before they hit reserve and 180 is not uncommon. Excessively rich jetting makes these engines run hot, and pollutes the engine oil with unburned fuel getting past the piston rings.

Posted: Sun Nov 03, 2019 1:26 am

Hey Doc, the jetting differences were real. The Canuck 11 made 108-HP vs the US 11@ 104. Just another reason why the north of the north of the border 11’s were more desirable.

Posted: Sun Nov 03, 2019 1:42 pm

Sorry about the thread hijack CRFAn1,

Can anyone explain the additional 4 hp in the Canadian bike, (in my opinion proper jetting does not affect peak hp reading the bikes just carburate better) but .... are there any other differences in the bikes .... carbs, cams, pipes air box ect. all appear to be the same (US cam part # = CAMSHAFT, IN. 14100-MG5-670 / CAMSHAFT, EX. 14200-MG5-670) ... Did the Canadian bikes get better cams? More compression US piston # = PISTON (STD) 13101-MG5-670? Were there different internal in the European 1100's that were used in the Canadian bikes?

There is a shop just outside Watertown NY that has a dyno but finding two bone stock / similar condition bikes to run side by side would be the trick!

Knowing that manufacturing tolerance stack-ups combined with assembly differences (human involvement) can lead to such differences it would be interesting to know what actual part(s) caused this 4 hp differential? In other words did they randomly test one (1) weak US spec bike and get one (1) strong Canadian bike or were several bikes tested showing similar results? Did they test the US bike in LA on a hot smog filled day and the Canadian bike in Vancouver on a cool oxygen rich day? Parts are exact while testing brings in the human variable.

Posted: Sun Nov 03, 2019 2:43 pm

Canadian to US exchange rate that particular day.

Posted: Sun Nov 03, 2019 4:29 pm

The carb bodies are different part numbers, VB56A for the US and VB56B on the Canadian carbs. And the Euro 1100f used different carbs as well.

With everything in common except the carbs either there is a difference there or back in the day someone messed up preparing the English marketing materials. I doubt that Honda US/CA was responsible for the dyno runs, which were measured at the crankshaft and not the rear wheel.

Posted: Mon Nov 04, 2019 3:24 am

Doc... The airbox isn't as fugly as removing the rear shocks.

Posted: Tue Nov 05, 2019 2:16 pm

Probably the 40 slow speed jets instead of the 38's?

I have a copy of the original Cycle world article ... I wonder if the Canadian bike dyno run's were shown in print?

sillygoose wrote:

The carb bodies are different part numbers, VB56A for the US and VB56B on the Canadian carbs. And the Euro 1100f used different carbs as well.

With everything in common except the carbs either there is a difference there or back in the day someone messed up preparing the English marketing materials. I doubt that Honda US/CA was responsible for the dyno runs, which were measured at the crankshaft and not the rear wheel.

Posted: Tue Nov 05, 2019 8:12 pm

Magazine dyno runs would be rear wheel numbers and lower than the 104 or 108 crankshaft HP numbers that Honda had published.

Posted: Tue Nov 05, 2019 9:46 pm

I just wonder if this alleged 4 hp number is real or perceived? I'm truly not trying to be a dick I just want to know how, why or what the engine differences are .... this information has been bandied about before and other than the (correct) 40 slow speed jet vrs the 38 in the emission crippled US bikes I have been unable to substantiate any other engine related differences or the factual basis for this urban myth. I would not be surprised if the Canadian bikes made 4 additional hp in the part throttle range when the US bikes were stumbling due to the lean condition?

Posted: Wed Nov 06, 2019 12:42 am

According to the test of the Canadian bike from the June 1983 Cycle Canada, "The carburetors are also jetted differently, since emissions didn't meet U.S. standards. The result is a better running engine that warms up more quickly, and makes about 5 more horsepower, too (exact figures aren't available)
Is there any difference in the compression ratio? My owners manual, as well as the specs in the test article, the Canadian engine is 9.7:1 but right under that, it lists the HP as 108@9000 rpm (US model) I wonder why they wouldn't have had the CDN HP spec. I always heard it was about 110.
Anyway, here is the link to the full test.
http://www.cb1100f.net/Other/cyclecanada1983/cc1983.pdf

Chris

Posted: Wed Nov 06, 2019 1:55 pm

Thanks Chris, I knew you would have the answer! As you said the proper jetting may be the answer. I looked up everything I could and the jetting was the only thing I could see.