XS1100H project, could use some advice.

[Dragoon]

So I recently purchased a Chopper/Bobber frankenbike as a project to hopefully get running and street legal before spring. The engine and frame is off an XS1100H. The front of the bike is a 71 shovelhead, and the rear is the Yamaha plus some peices off a harley welded on there. All in all its a pretty solid bike just needs some TLC. Now however I'm having trouble getting it to stay running.

First off, everything I've done: The gas tank was rusty and nasty on the inside so I shook the hell out of it with some aquarium rocks for a week or so then applied two layers of redcoat to the inside of it. I had to order a petcock which I installed as well as some fuel line and a fuel filter. I used a clear fuel filter just so I could see to make sure there was no gunk left in the gas tank. Bought a new battery for it. Replaced the rear wheel bearings and the back tire. Changed the oil and oil filter as well as the final drive oil.

Before I had the gas tank installed I had an old plastic lawn mower gas tank on there just to crank it up. And it would run with the plastic gas tank on there but it would spit and sputter and sometimes die if I gave it any gas. I did'nt crank it up too much like this becasue I don't like running it without a fuel filter. Now however, if I crank it up with the original gas tank on there it will turn over but not start. It acts like it wants to, but when it does fire off it backfires horribly and I can see smoke and I think gas shooting out of where the air filter is supposed to be. I can smell gas pretty bad too.

That's another thing looking at the bike the air filter that is on there does'nt look like any air filter I know of. It looks like just a mesh screen sort of like a window screen.

I have a feeling its some kind of simple carb adjustment or something that I'm overlooking. Whatever it is, it can't be that much to it because the bike was running. Thing is I don't know that much about the history of the bike so I can't say for sure the last time it was really used. Maybe I have run the fuel lines wrong or something? I dunno but its a bit frustrating to say the least.

I have yet to paint the bike but I wanted to make sure its mechanically sound and running before I got into that.

So I'm appealing to the wisdom of this forum hoping somebody can point me in the right direction as to what to look for. I'm a pretty novice mechanic and any advice would be greatly appreciated.

[tarzan]

It sounds like the float valves are leaking to me. I would pulled the carbs and go through them. I see a thorough carb cleaning and rebuild in your near future.

[Dragoon]

It sounds like the float valves are leaking to me. I would pulled the carbs and go through them. I see a thorough carb cleaning and rebuild in your near future.

I was hoping to avoid that but I'm afraid you might be right.

[JeffH]

The gas tank was rusty and nasty on the inside

Before I had the gas tank installed I had an old plastic lawn mower gas tank on there just to crank it up. And it would run with the plastic gas tank on there but it would spit and sputter and sometimes die if I gave it any gas.

I have a feeling its some kind of simple carb adjustment or something that I'm overlooking. Whatever it is, it can't be that much to it because the bike was running.

If the gas tank was all nasty then all that crud is in the carbs too. I agree with Tarzan, need a really good carb cleaning. Each carb likely has a different problem. Some clogged prime circuits, couple clogged pilot jets, a nasty main nozzle, a stuck float, leaking needle & seat etc. Yes, the bike runs but that is not an indication that all is well in the carbs.

It might 'run' but it won't run properly until you do a good carb clean. Many of us has btdt with the exact situation you described. I good cleaning and maybe some new parts works wonders.

Jeff

[James England]

IMO you don't stand a chance of clearing this up unless you remove the carbs and give them a thorough, meticulous clean. It's a question of eliminating possible causes and this sounds very much like the carbs to me. Any neglected, Franken-type bike has most probably never had the carbs cleaned.......

As a small example.. Recently cleaned and rebuilt the carbs on my last project. On putting it back together, the bike wouldn't start easily, ran badly, a variety of weird symptoms like revving and not coming back down, revving and staying up etc ..... I removed the catbs and stripped them all again....and found some crud I missed when I first did the job. Just a tiny bit of filth caused all that. Now it all sounds and runs brilliantly.

Your carbs will have all sorts of crud in them, for sure. Don't be daunted by a carb strip. It's the same thing four times over. Removal of the catb bank is not difficult if you loosen the air filter housing bolts at the rear clamp and drop that clamp under the frame. That's if you do have the OEM airbox on. Drop the box at the back, pull of the carbs and start the job. BUT...buy a good set of screwdrivers for jet removal...do not risk ruining the jets because you don't have a good fitting screwdriver with the correct size blade.

This topic is well covered here. I'd suggest starting a carb removal, strip and clean and regularly post your progress so that people can help you along the way. Contrary to what many people do here, I would strip and clean one carb at a time if you are inexperienced. Do one carb from start to finish and move on to the next one. This will save you having four carbs' worth of parts lying around and getting bogged down or disheartened!

[Dragoon]

Very sound advice gentlemen thank you much

I've taken apart the carberator on my polaris ranger and cleaned it before and put it back together so I imagine these won't be all that much different. The polaris carb was a single though so I havent had to deal with having a bunch of parts lying around. So thank you for the advice James.

Off to find the carb cleaning thread and bookmark it and start taking her apart!

[natemoen]

Just do one carb at a time. Clean it and put it back together and move to the next one.

Here is the thread you need.

http://www.xs11.com/forum/showthread.php?t=36017

[motoman]

Very sound advice gentlemen thank you much

I've taken apart the carberator on my polaris ranger and cleaned it before and put it back together so I imagine these won't be all that much different. The polaris carb was a single though so I havent had to deal with having a bunch of parts lying around. So thank you for the advice James.

Off to find the carb cleaning thread and bookmark it and start taking her apart!

Likely no need to seperate carb bank either.

[TopCatGr58]

Hey Dragoon,

You've already gotten the best piece of advice you need, clean the carbs.

You said it has an 81H frame/engine...however, with frankenbikes, we often see all sorts of weird things. SO...I would not assume it has the correct ignition module...look at it, should be labelled with a 4R1 prefix on the black box. IF it has 2H7, then it will have the wrong igntion module for that year/model. However, PO's have done lots of strange things to get bikes running....like swap igntion parts. The 81 TCI(Transistorized controlled Ignition) unit was changed, it incorporates the centrifugal timing advance into a computer chip, so there shouldn't be any mechanical centrifugal advance parts on the left timing plate area. There should only be a vacuum advance pot, along with the pickup coils.

The 78-80 "2H7" TCI's utilized mechanical centrifugal and vacuum advance components under the timing cover, it's a simpler design. The 81 4R1/4R0 TCI's are more complicated, and more rare, only made for 1 production year, and then Yamaha changed the TCI again for the 82 XJ incorporating both mech. and vac. advance timing curves programmed into chips in the TCI.

SO...that 81 engine should only have the vacuum advance pot, no mechanical advance parts, and the 4R1 TCI. IF the TCI died and the PO put in a 2H7 TCI, then it won't be able to rev much because it won't have the proper mech. advance!

IF it has been modded and had earlier timing parts added, like the mechanical advance parts, THEN if it has the 4R1 TCI, then it will develop TOO much mech. adv. timing, and again won't run right.

The earlier 2H7 series had more flexing of the PICKUP coil wires under the timing cover due to the activity of the mech. adv. as well as the vac. adv., and so the wires often get worn and break causing intermittent spark symptoms....see the Repair Pickup Coil wire tech tip. The later 81 don't wear/flex as much so they are less likely to break.

Just wanted to give you this extra info so you can check things out in case after the carb cleaning that it still has running troubles/issues.

T.C.

[MarkD]

There is a fine video from motorcyclememoir that illustrates most of the procedure of tearing (gently) into the carbs. DO NOT BE AFRAID to do your own work. I did this stuff, you can, too. These guys here are patient and smart, they will help. --here's the link:

http://www.youtube.com/watch?v=95nlrP-yn2I

[MaximPhil]

Very sound advice gentlemen thank you much

I've taken apart the carberator on my polaris ranger and cleaned it before and put it back together so I imagine these won't be all that much different. The polaris carb was a single though so I havent had to deal with having a bunch of parts lying around. So thank you for the advice James.

Off to find the carb cleaning thread and bookmark it and start taking her apart!

Hi Dragoon,
As sad as I am to hear that an H was hacked up. Good luck with your project. As mentioned the H has some unique parts. The ignition as mentioned is different. Check to be sure which carbs you have and follow the intruction that relate to them. After 34 years of abuse you could have a real mix of components. Do read the carb write up as you may as well clean it all the 1st time or the dreaded triple clean will be in your future.
Do figure out where the holes are and make sure you are not looking into one when you spray the cleaner......and get all the crud and cleaner in your eye
Some pictures would help the Carb gurus determine exactly which model carb you have.
Phil

[Dragoon]

I spent all day disassembling, cleaning and reassembling. Lots of gunk and old gas in there that had to go. As soon as I got it all back together and put it back on she cranked right up beautifully I should have done that to the bike first thing probably.

Even though the bike probably sat for a year or two the guy that I got it from took pretty reasonable care of it. Had a few dirtdobbers make nests in some of the engine but all in all I think she's going to turn out great when I'm done with her.

I'll have to take her apart again so I can finish getting the flames painted on the gastank and paint the frame as well. Someone melted the soles of their riding boots on the pipes lol so there is that to clean off . I've been dealing with stage 4 Metastatic Melanoma since 2011 and since I'm disabled now I have nothing but time on my hands. I'm trying to heal up not so much from the disease but from all the stuff the damned doctors have done to me over the past 3 years. So It feels good to just tinker around in the garage with a good project like this bike. Its something I've always wanted to do but never had the time to do before.

As soon as I get her painted I'll post some pics if anyone is interested. Thank you much fellas I'm sure I'll be asking for more advice in the near future Thank God for this website is all I can say.