HarleyTechTalk

'89 1200 on a stock motor, open pipes and free flow air filter. The main jet is a 200. The bike runs fine on this but I have a 180 I'm thinking of trying to see if I can increase tank range. Does this sound like foolishness?

worth a try, I think a 200 main jet seems a bit large anyway. 

That is a HUGE main jet for a stock engine. How long have you had that in? Cylinder wash could be an issue now. What size is the pilot? Is that even a CV or is it a butterfly?

the stock carb on an '89 is a CV.  I doubt a 200 main will wash the cylinders down, heck the Buell's and Sporty Sport's ran 195 mains. 

That main jet does seem a bit large for a stock motor.
The pilot jet is going to have a more overall influence on mileage.

Yep I'm with it being a bit of on the large side - I'd try the 180. I have a 175 or 180 (can't remember) on my 1200 conversion with cams and flowed heads, seems about right. the stock CV is very forgiving for the wrong jetting, but you could certainly get a few more miles out of it that way I would think. Yours is a crossover model for the CV I think - it may or may not have the brass accelerator jet sticking up in the throat of the air intake. the later ones (like mine) do. Not sure if that makes any real difference for the jet required tho', as it only squirts fuel when you open the throttle.
The idle jet should be a 40 or 45, and rememebr there is a mixture screw for this one.

Yeah - I had previously swapped out the pilot jet which fixed a low speed running problem. I'd expect the 200 has been in there pretty much from new, and hence will have covered most of the 14000 miles the bike now has under its wheels.

The bike goes up on the ramp this coming weekend to pull out the inlet manifold and reseal. I'll drop that 180 in at the same time and check what the number is on the idle I'm now running. I guess a plug chop should show if I'm going too far out. I'm running a CV, but which has no acc pump - std for that year I believe.

yep, that sounds about correct. Like I said the CV is very forgiving with its mixture settings, using the intake air velocity to suck in the required fuel. Try the 180 for sure. Am pretty sure that the 200 is not stock for a 1200 from new of any year, I think the 1200 sport with the 4 plug head had about a 190ish from new but there u go. but if it was too far out the plugs would have been really messed up I would guess.
funny about your carb, my bike is an october '89 (so a '90 model year build) and has the accelerator pump.
14,000 miles - that was a good buy, mine has gone well past 100,000....!!!

Actually got the bike up on the ramp earlier this evening. It's all a bit odd in there - and I'm talking about the manifold now. It's a moulded rubbery one piece with alloy plates that bolt to the pots. on the inside is a steel band. I can't see how my new replacement rubber gaskets fit into this arrangement. In fact the manifold material is softer at the interfaces and effectively at the cylinders it is clamped between the alloy outer and the steel band inside. The face of the rubber squeezed between the outer alloy and inner steel then buts up to the cylinder, with perhaps a thin paper gasket there; it's kind of slightly fury though no gasket cement appears to have been used. This does not match the pics in the parts manual ... in the same way that my carb differs; with no acc pump. I seem to have some odd interim model here.

Think I'm going to need a new manifold.

Hmm that is odd - from the part manual your '89 should have the same stock CV as mine. Does your carb have a rectangular base or a round one? the rectangular one is the later model. The stock manifold is an alloy piece, with steel (or alloy?) mounting flanges. There is a large rubber washer in the connection between the carb and the manifold.
You have the part numbers in the part book - a search on ebay should find you what you need. Have never seen a rubbery inlet manifold on a sportster, but that's not saying they didn't come like that...
cheers
A

Ringing around the dealers yesterday elicited pretty much the same response - never seen one of those. Managed to score a replacement in alloy 2nd hand for £15 (GBP). All being well I'll have that for the weekend and get everything bolted back up whence I can check out that 180 main.

Sounds good. You will need the 2 mounting plates for where the manifold fits the heads, and they come with a rubber ring inside them which acts as a gasket for the inlet if you don't already have them. Also the large circular gasket for the manifold to carb joint.

Yup - a quick plug for Grizzlies here in the UK who came up with some very well priced s/hand parts delivered Friday in good time for the weekend. All went together swimmingly on Saturday morning. Swapped out the main jet whilst I was there of course. The hole down the middle of a 200 is so big you wonder why they bother bolting anything in there at all. Saturday evening I figured I'd roll out to see my favourite speedway team in action but despite a spell on the charger the battery gave me only around 20 secs of life free spinning before failing. Had to haul out on the trusty iron head Beezer.

After another overnight charge I popped off the air filter, sucked up some gas from the tank with a bit of old hose (not hosiery note) and blew it through the carb. She then lit up on the button. Frustratingly I'm now out for a week before I can test the new set up the weekend after Easter. Probably a run out to Black Bear HD at Newmarket. Gives me a couple of days then with any final tweaks before catching the boat to Denmark. Gonna need another battery though.

Cool mate hope it all goes well. I'd go for the OEM or Odyssey gel batteries as they last a whole lot longer than the cheapo lead acid ones, and don't make a mess of the bike with spills either...
With all the waether you have been having check out the connections on the HT leads, particularly where the earth mounts on the rear engine mount plate. This can trap water in between the plastic jacket and the wire, leading to corrosion and a horrid earth problem.