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gnarleyhaterson
12-31-2013, 3:42 PM
Hey guys, I'm Graeme. New to the forum and pretty stoked to have so much awesome info at my fingertips. I had a couple questions regarding my project that I'm getting a lot of mixed info about and I just wanted to clear a couple things up before I start tearing my bike apart.

So I'm doing a 1200 big bore conversion kit on my 2000 XL883. From various reading around I'm under the impression that I should be upgrading my ignition module to either a stock 1200 unit or a programmable aftermarket unit; at least that seems to be the general consensus online... Now I asked the guys at my local performance shop if it was necessary, and they said I should be doing my cams or heads before I bother with my ignition, and that they do the 1200 kits all the time with stock 883 ignitions. This struck me as a bit contradictory to what I've read. I figured they're probably just trying to sell me on their fancy ported head kits, which I would love but it's just not in the budget right now. Anyone here want to weigh in on this? I'm on a major budget so I'd like spend as little as possible here, but the last thing I want to do is halfass this project and end up wrecking my baby. I'll probably end up picking up one of the el-cheapo Ultima kits but I just wanted to see what everyone else thinks.

Also, should I be upgrading my clutch? Again there seems to be quite the divide on whether or not it's necessary. I don't ride particularly hard, but again I feel like this is one of those better safe than sorry situations. Pretty much answered my own question there ha.

I'll be starting a build thread as soon as I start the project. This little yellow bike is going to be going through a lot of changes over the next few months. Looking forward to everyone's input.

junkyardxl
12-31-2013, 4:52 PM
You don't have to do anything. Keep the stock ignition it has a higher Rev limiter. Stock heads and cams work fine. All you need is a carb tune.

gnarleyhaterson
12-31-2013, 5:21 PM
Thanks man. I had read that a 1200 requires 28 degrees advance timing, as opposed to the 883 ignition which is set at 35, and that people have had issues with pinging and rough idle using the stock module. Maybe that doesn't apply to my model, or maybe people are misdiagnosing their problems. I figured that the stock heads and cams would work just fine. I guess I'll put everything together when the big bore kit comes in, and try a different ignition if I run into any issues. I've already ordered new jets.

junkyardxl
01-01-2014, 12:41 AM
I've got thunderstorms heads and aftermarket iggy with a 11:1 comp at least. On top of a 1250 kit. Your stock iggy should be adjustable to prevent detonation. All the hype of upgrading cc is way over rated. Worth it but not nearly as difficult as made out to be

Easyricer
01-01-2014, 6:57 AM
A few simple things to keep in mind when doing an 883-1200 conversion; first off do you want to just get a bigger bang as in more smiles per mile? Just boring out the stock cylinders to 3 1/2 inch and putting a set of reverse dome pistons will do the trick nicely. No head work, re-balancing or cam work needed. You will have to readjust your timing and jet the carb.
If you are looking to blast past everything on wheels? You'll need your heads ported, racing valves with high lift springs and collars, new cams, SE (or aftermarket) ignition, a Barnett clutch upgrade and tires that will hold all of that extra power.
Since you obviously don't want to dump $2000 into the conversion, I'd say just keep the stock ignition and cams, punch it out to 1200 with the reverse dome pistons and ride the tires off of it!
The carb work and ignition timing is very simple to do all you need is a little confidence and a nice long hill to ride up helps a lot. NO trade secrets there at all and no DYNO needed.
I've lost count of how many Sporties I've built and every single one of them is still running down the road with a very happy owner.
EASY

BrokenSprocketGarage
01-01-2014, 8:15 AM
I always build my customers engines to their budgets. Put as much money into the internals as you can. Wiseco reverse dome pistons, bore your stock cylinders. Cometic gasket kit with MLS head gasket. Do not exceed 9.5:1 compression ratio. Pump gas with ethanol does not work for higher comp. ratios. I
I have an 883-1200 job in my shop now. Quoted customer $2000 installed with Twin Tec ignition.
Including Andrews cams, stock heads, Wiseco pistons, cylinder boring, Cometic gasket kit.
I did one this past summer with points ignition and it ran awesome! Had a great idle, cheap and easy to adjust. Minimal wiring.
You do not need a Barnett clutch spring. Or any other clutch work.
You must rejet your carb!

junkyardxl
01-01-2014, 10:27 AM
I always build my customers engines to their budgets. Put as much money into the internals as you can. Wiseco reverse dome pistons, bore your stock cylinders. Cometic gasket kit with MLS head gasket. Do not exceed 9.5:1 compression ratio. Pump gas with ethanol does not work for higher comp. ratios. I
I have an 883-1200 job in my shop now. Quoted customer $2000 installed with Twin Tec ignition.
Including Andrews cams, stock heads, Wiseco pistons, cylinder boring, Cometic gasket kit.
I did one this past summer with points ignition and it ran awesome! Had a great idle, cheap and easy to adjust. Minimal wiring.
You do not need a Barnett clutch spring. Or any other clutch work.
You must rejet your carb!

Why not higher compression than that? I'm running pump gas I just retarded the timing till no ping.

Stlmikie
01-01-2014, 11:58 AM
If you have to retard the timing aren't you defeating the purpose of raising the compression?

BrokenSprocketGarage
01-01-2014, 12:29 PM
What stlmikie said as for higher compression ratios.
The gasoline around here (Western New York) is 10% ethanol blend. It just isn't explosive enough for hi-comp engines. On top of that we have seasonal gas blends due to winter weather. On top of that we have a 5 month riding season if weather is good. Most riders don't put much more than 1000 miles per year. So the gas sits around in the riders tank, gets a little stale, a little water in it, and is just barely keeping the bike running. Even fresh fuel causes pinging.
Only when I have a really educated customer, who is aware of the low quality fuel and willing to go the extra miles to get ethanol free fuel, will I then consider a higher comp. ratio of 10:1.

Maxxvr
01-01-2014, 12:48 PM
What stlmikie said as for higher compression ratios.
The gasoline around here (Western New York) is 10% ethanol blend. It just isn't explosive enough for hi-comp engines. On top of that we have seasonal gas blends due to winter weather. On top of that we have a 5 month riding season if weather is good. Most riders don't put much more than 1000 miles per year. So the gas sits around in the riders tank, gets a little stale, a little water in it, and is just barely keeping the bike running. Even fresh fuel causes pinging.
Only when I have a really educated customer, who is aware of the low quality fuel and willing to go the extra miles to get ethanol free fuel, will I then consider a higher comp. ratio of 10:1.

I'm doing the NRHS 1250 kit, which has a compression ratio of 10:1.
The gas station in my town is ethanol free, I also live in WNY.

howard
01-01-2014, 1:57 PM
some sunoco's around syracuse have eth free 91 now-
and most nice and easy's also

Easyricer
01-01-2014, 8:11 PM
Seriously, dude, don't sweat the big horse power! 883 TO 1200 is about as straight forward as it gets. Anything beyond the standard reverse dome set-up and you'll be asking for more problems. Keep It Simple Stupid (KISS) is the best route to go. Yes 100+ HP can be had from an 883 conversion, but trust me you don't want all the problems that comes with it. Before you are done and the bike is reliable again you'll have dumped more than $5 grand into it and could have bought a gixxer.
Reverse dome pistons, jet the carb, play with the timing and ride the tires off of it. Works for 99.9% of the people who do it. (even a home build)
EASY

gnarleyhaterson
01-01-2014, 10:26 PM
Awesome, thanks for all the advice. I'm not looking to turn it into a race bike, so I've ordered a big bore kit with the cylinders and 9.5:1 Wiseco pistons. I found a good deal on an Ultima single fire ignition kit too so I picked it up anyways. I like the idea of being able to track I'll probably end up doing a few more things to it down the line, but I think this'll do for now.

dberman
01-03-2014, 8:37 AM
Mine's a '90 XLH. First thing I did was the 1200 conversion. I replaced the stock ignition with a Dynatek and mechanical advance unit (mounted in the gearcase cover nose cone). No clutch or cam upgrades, and no head work. I did, however, rejet the carb. The conversion kit (Wiseco pistons and pre-honed jugs) cost me something like $500 and was a relatively straightforward install. I'm sure I could probably squeeze more juice out of it if I did all the other changes that some people talk about, but the bike is quick off the line, runs like it's supposed to, and does all I need it to do.

Skylar
01-08-2014, 9:17 AM
...Looking at a local 1993 883 frozen in time, sitting for probably 20 years in an old garage, if the odometer is to be believed, 6 miles total.

Getting way ahead of myself (committed to buy it, still playing with a price and here in MI we just got record low temps and lots of snow, so I have time to think about it) I already started thinking 883 --> 1200 or 1250 since the gaskets are probably all dried out and it would need some work to get it back on the road again.

Thanks for the sage advice.

gnarleyhaterson
01-09-2014, 12:13 AM
And the parts are rolling in... UPS guy showed up with the big bore kit and gaskets. Now I'm just waiting on the ignition and other various farkles I've ordered.... and I gotta fix my fucking Geo Metro because my sporty is still a daily rider (January in Vancouver is lovely, you should come visit) and I can't afford any downtime at the moment. I'll post a few pics when I get everything started!