Hello everyone, back again to ask for some wisdom from all of you. I finally got my 81 FXS safe enough to ride (new tires, fixed my clutch problem, bled the brakes, etc.) and took it out for my first trip around the block today to see what's next. Anyways expected, I have new problems. This is my first project bike, although I have some wrenching experience from messing around with my old Chevy, so please excuse me if these questions sound a bit inexperienced or foolish. (I'd say I'm definitely a little bit of both!) For context, the bike has the original engine. I was told the engine had undergone a full top and bottom rebuild. (That's what they always say though.) The only big change I can see by eye is the dual plugs. It's running a Super E carb. As far as I can tell it's the original rotary top transmission. So the first problem from today's ride. The bike gets up to 3rd gear with no problem. However, when I finally get to 4th, it begins to sporadically slip in that gear only. It will ride fine for a while and then suddenly I can hear the engine revving but she doesn't want to go anywhere. Then it'll catch and it'll ride fine for a bit again. No jerkiness though, just a smooth transition from in gear to not by itself. It doesn't stall, just slips. This won't happen in any other gear besides 4th. If that makes any sense, I'd appreciate some input. The second issue that popped up was a bit of a rattle from the top end. I noticed after I turned the ignition off that there was a puff of gray smoke from the head gaskets, so I think those will probably need replacing. I do not know if the noise is connected to that though. Here's a link of the engine running with a little bit of revving since that's when it rattles even louder. It should be good for a few days. Let me know if you can't access it and I can try to find a different way to post it. If there's any other info I should've put just let me know and I can fill you in. I'm grateful a youngster like me has somewhere to ask his questions and have some experienced answers. Thank you guys.

 

Hi, you mentioned that you had a clutch problem that you fixed, what was the problem to start with ? & how did you fix it ?, it sounds like it could be in need of adjustment of the spring presure plate (3) nuts, sounds like they could be tight enough in 1-3 gears then slip in 4th being 1to1 ratio : do you have an original service manuel ? if not you'll defintively need one, they are not that expensive and will save you a lot of head aches ! Good luck, let us know how it goes !

 

If its puffing smoke from the head gasket then the heads need to come off SOON as it will not if work the cylinder head and its prolly worked now but real damage can happen running it

clutch issue - explain what you did and How you did it - will help in a small mistake that inexperience with this type machine can and does happen

its not an old Chevy i wish it was — its more like an obscure farm tractor no one ever heard about

 

sounds like it needs a valve adjustment, or the rocker arms clearance checked. as john said, don't run it with a leaking head gasket, it'll burn thru the aluminum and you'll be looking for new heads. heads can be removed with motor in frame, but get the factory manual first!

 

Hello everyone, thank you very much for all of the helpful responses. To start with, I do have the factory service manual. I bought the factory HD and the Clymer manual and they have been a tremendous help. When I first got the bike, the clutch did not want to disengage. I pulled all of the plates, cleaned the gunk that had accumulated between them from sitting, and put them back on. I adjusted the free play in the clutch cable according to the service manual and set the spring compression distance to the 1 1/32 in. that the manual said. After Troy's recommendation this morning I went ahead and gave the three nuts two turns each to try and tighten them up a bit and see if it helped or not.

I hadn't seen John or Joe's messages yet or I would have definitely not taken it out today, but this morning I did take it for a very short ride after the clutch spring adjustment to see if it did help. I live behind a straight away road that never has any traffic on it, so after letting her warm up for about ten minutes or so, I went through the gears to see if the clutch adjustment had helped. I also wore my half helmet this time instead of my full face to hear a little better. What I noticed on this ride was that when it slips in 4th, the engine seems to quit a bit too. It doesn't die out, but it doesn't sound responsive to the throttle at all. Then, there's a big backfire from the exhaust and it will all catch up again. The backfire would be followed by 4th gear catching again every time.

It did not puff the smoke from the head today, but I did notice there was a bit of an oil spot on the fin closest to the head gasket. It looks like I will be parking the bike for now and reading up on how to do this repair before it gets worse. As far as head gasket replacements, are there any tips you guys have for a complete beginner shovel mechanic like me? Any specific recommended manufacturers of head gasket to order from or certain things to check or remember while I'm pulling the heads off? I do have the service manual so I will most definitely be going over the cylinder head section a few times before I even start the job. I will also be reading about the valve adjustment and rocker arms clearance procedures as well. Thank you for those recommendations Joe.

 

have a look up on utube some really good stuff on there.
try pacific mike for a start.

 

Hello again everyone, thanks again for the advice. I finally got a chance to start on the teardown. Service manual and pacific mike were a big help. So far I've pulled off the front head and it's not looking too bad. You can tell it was leaking but the heads aren't looking wavy or too bad. I included some pictures of the front head and cylinder. I had a couple of questions if anyone could spare the time.

One is the carbon build up. The plugs did end up being pretty black and as you can see in the pictures, there's a lot of buildup on the valves. What should I use to clean that off before I put everything back together?

Second is that one headbolt is hitting a cylinder stud and I can't seem to get it out. I bought a new set of head bolts to put in. Should I / can I pull out that one cylinder base stud or would I have to loosen all four to avoid warping it? How do you guys go about that?

Lastly is a quick one. I made a total beginner mistake and knocked a small piece of fin off the cylinder. Nothing too major. Would JB welding that work?

 

The fin forget it or have it welded back on with the jug off the bike only

the carbon is always a thing when things are worn out - wire brushing it off is a bandage on a wound

to me its rings seal along with valve guides and guide seals usually cause that and its not going to get better with out repairs

 

That makes sense. I'll look into swapping those out. What about those head bolts? Is there a way to get those out without pulling the cylinder off?

 

You will need a factory service book or you will loose your place and leave stuff not tight in places you have to take the bike apart to get to

take all 5 head bolts out they go up into the heads. 9 / 16 box type wrench = then the head will pop off the jug

IF SOMETHING ELSE IS GOING ON THE ENGINE NEEDS TO COME OUT TO REMO VE THE HEAD AND JUG TOGETHER