Hello and Tech stuff.

[ClarkGriswald]

Aye sorry bout the thread discrepency, it was kind of a cap to the last one that was in this forum or I would have not put it here.. but yeah I get it.. Im no stranger to the forum thing, my name came from when I started drivin an old jeep wagoneer with the woodgrain side.. my buddy started callin me clark griswald from the vacation movie.. (family truckster). so I used it on the FSJ (fullsize jeeps) forum, so now I just use it everywhere..

[bikerphil]

clips in pan

One of these clips is probably what was found in the oil pan. They hold the middle drive gear in place between the two case halves.



HTH.

[XSPastor]

One of these clips is probably what was found in the oil pan. They hold the middle drive gear in place between the two case halves.

I concur. Unless the PO replaced them with other/new ones and dropped one of the old ones in the crankcase, you could be riding around with only one holding your bearing in. I'm not sure if that's a big problem or not but I'm sure Yamaha didn't put it in there 'cause it looked good.

[ClarkGriswald]

To reply to the other post, I had my carbs completly dissasembled when I had the bodies in the soak.
Throttle shafts and butterflies removed (after filing off staking on screws before removing..). I love working on carbs.. I put new stainless screws back in the butterflies it turned out nice.
Now the only thing I did not do as I had said was to leave the idle mix screws alone. Im thinking I should definatly access those now that Im running so that I can further tune it , although it is very smooth and runs good starts fine instantly ect.. lots of power but a little hesitant in the low revs which I know can be worked out.


One thing I never mentioned.. this bike is a frankenstien of some sort.
Steering stem says 6/78 my title is 79.
The engine is a 3j6 number so 80 special of some sort? Round headlight and front turns so, could have been wrecked or blown up or whatever. Frame number and title match though, it is legitimate.

The carbs had the 115s on the outside and 120s in the middle and other aspects told me that they must also be with the 80 engine. Now, the #1 carb has been thru some kind of serious action. The float bowl drain bolt and surrounding structure is ripped away and was jb welded up (or something like this). also there are several weak/cracked spots in that bowl. the main deal is the area around the throttle shaft seal/flange whatever on the left side of #1. about an 1/8 inch chip was broken out of that so the PO had put an oring in there.. wasnt a bad idea but it was old and soft and was "squished" out of that little V shaped chip.. I turned a piece of purpleheart (hard some scrap layin around) into a plug that matched the throttle shaft hole, and also went out and simulated the outer face of it.. so, epoxy will not stick to plastic wrap very well so I tightly wrapped the wood plug and inserted it,, then JB welded around there a few times.. so that I have refomred the missing area. Now, I have an O ring in there that fits really nicely, much better than the other 7 shaft seals that are Ok , not perfect (thought I may still buy them and replace all 8). But it works well. and I found a fiber washer to go under that snap ring that kinda supports that o ring in there..

Thats my carb story. They are super clean except for the idle screw aspect of the pilot circuit, it is a "circuit in waiting " as it were. hehe

[TopCatGr58]

Sorry to make you retype what you essentially had already stated in the beginning of this thread! BTW, did you put lock tite, or pean over the ends of the SS screws you put in the butterlfies??

I reread this thread briefly, so I could have missed it, but how long had it been sitting?? The low compression possibilty could be from that, partially stuck rings, or just needing a few hundred miles to rub off any surface rust on the walls and reseat the rings? I'm sure you know to remove all the plugs, gas OFF, but throttle wide open to get the Comp. readings, also recommended to be done on warmed up engine!

You've already done the oil change, however folks have put a few ounces of MMO in their oil, and ridden it that way to help unstick rings and clean off valves and such!! So...I wouldn't be too worried about the comp. readings just yet, put a few hundred good highway miles on it, and then retest it.

Yes, being able to adjust the pilot jet screws will aid in tuning to help reduce/remove the low end stumble. I know you've bench synched the carbs, but have you vacuum synched them??

Keep at it!!
T.C.

[ClarkGriswald]

Sorry second post, not tryin to keep this thing goin but thought of something related to the last one hehe.. Ive rebuilt tons of carbs, its a curse ya know. When you get a knack for something, everyone has ya doin theres hehe.. back when I raced quads I was always cleanin em for people.. but in all these years (and cars and other stuff), Ive never seen carbs so stuck up and varnished and rotted and green corroded . hahahhah.. It was really a challenge.. If the thing blew up tommorow Ive already had a ton of fun scrubbin my fingertips off with a brass brush hahaha.. I bought NO parts. All the needles/seats under the floats are what was in there and I mean Nasty, the spring loaded deals in the needles 3 of em were solid heheh.. now they work perfect (at least for now Im sure someday Ill get new parts) Even the needle tips, there wasnt a ring impressed into the rubber yet so I rehabed them too. haha.. bought new o rings at the hardware store. 2 days for #1 (lots of repairs on that one), 2 more days to do #2 and prep #3.. the next weekend 3 days to finish up 3 and 4 and reassemble the whole mess with new screws. That project alone made my whole year hahhaha.. Just thought I would elaborate on how bad they were, the bores were nasty, had to carefully scrub em with a softy brass brush (with some mothers as lube, (not removing surface just massaging the funk out of the metal.. Only reason I dared with that was because of the powdery corrosion, it wasnt eating it yet but would have eventually , pluss a lot of drag/friction on air when its like that.. after that a shot of carb cleaner made em grey again rather than half shiny but they are smooth instead of rough.. I kinda screwed myself by workin so hard on the first one,, then i had to do em all like that hahhaha.. But hey,, now instead of my hands goin numb from scrubbing, its because of handlebar vibes hahahha.. Wooot

[ClarkGriswald]

Ok thanks for the reply, Yes I used blue locktite on the ss butterfly screws.. I bought a bag of 50 for like 2 bucks and change. with shipping it was 8 bucks.. now I drove around to 4 hardware stores that day and they had almost what I wanted but I dont settle for anything but whats right. So now if I take em apart again and ever have a prob with the phillips head.. Ill replace em. I bought em a hair over the normal length.. then I put them into the throttle shaft, snugged em slightly and then carefully milled the ends off on a stand mounted belt/disc sander until they were pretty much the exact length of the orig screws, I wanted to simulate the exact stock situatioin. I guarantee that some engineer figured out how long those were supposed to stick out in that lower hollowed flat of the shaft.. (I see a wind tunnel in my head).

Then when I installed them they were identical to stock but instead of staking I locktited them and then reached in with a q tip touched on a rag with xylol on it and cleaned the residue off the tips of the screws. It never hardens in free air as I understand, dont want that goin in there even in trace amounts,, any chemicals like polish or anything i used on the brass parts , I cleaned them off with carb cleaner and then purple type degreaser to remove any residue that could wash into the motor (even in trace amounts) Ok Im gettin way to anal on it but what the hell I have fun workin on em.

As for the second part, yeah it had sat for probably at least 4 or 5 years and from what Ive seen in my exp I imagine a lot longer, It has a mag mopus on the rear and an ole spitfire2 on the front. both have some dry rot so Im really not wanting to put tons of miles on yet till I get some new "interface with the road".

But a good friend of mine, grew up on the farm. The real old hard farm life hehe.. now he still loves the old machinery and one of his favorite sayings is, "It just needs to be run". haha.. he's the one that gave me this bike (and was gonna junk it, reality was he knew I would go hog wild on it and make it work hahha. ).

I never benched em I just do it by eye I made my honda run real well but always have that in the back of your mind that its not "quite" right. so now i have a set of gauges. when I first fired it up i did a quick sync.. the first day i drove it like 3 miles to my sis's place.. her boyfriend said. "oh cool the pipes are turnin blue". haha. and i said oh thanks for pointing that out cause i meant to check that.. and then i pointed out to him that 1&2 were slightly blueing, but 3&4 were gold. heat caused by lean, later that day I resynced and yes., there was an imbalanced between teh banks. so good diagnostic by accident by my buddy hehe.. My air filter was wasted.. the foam/velvety stuff all fell right out of it when i took it apart (thank god i know not to just try starting something hahaha, would have sucked right in there). right now, im waiting on a K&N to fit the stock airbox.. so Im running the metal cage left from the old filter , and I wrapped some foam filter material
I had around it and put a few wires around the edge.. its pretty free flowin though so attributes to lean condition , but a K&N's comin so , aside from overoild kns it shouldnt be too much of a diff in air flow , but .. Im waitin on that thing to get here before I put much more miles on and further tuning

I know.. out here in the country we even fashion our own filters haa..(your lucky its not an element from a shop vavc.. I thought about it hahah). .I tore up an ole foam filter sleeve thing and wrapped it on there. hheeh.

But in that respect.. "In your face" gasket manufacturers. hahah. I made my own gaskets for my clutch/shift/bottom and they were probly better than ones you can buy.. I know I like stupid stuff.. the process is almost more fun that the end result sometimes for me.. then I had a scrap left today to do the cam chain adjuster hehhe..

[ClarkGriswald]

oop.. missed the 10 min limit to edit and ad this.. just something I thought of maybe already known.. brake line for cars.. you can use that for a nice punch to make gaskets, use a size like the bolt hole your doin, and if ya insert a cone shaped dremel bit into it, it makes a nice punch. not only for marking the gasket material but then put it on a piece of cardboard on top of a piece of wood or floor. and hit it with a hammer. awesome punch. I take a paint pen and "color" the gasket surface of the clutch cover for example and then "stamp" the impression onto the gasket.. then just shoot some carb cleaner at it and wash the paint off your side cover so it doesnt dry..
after your stamped image dries you can set the cover back over it, trace the outside with a pencil and use the little piece of brake line to mark the holes.
then stamp the holes out for real, then i just draw the inside with a pencil and its a razor knife away from awesome. .. metal brake/fuel line is good and standard sizes easily make good enough holes for metric bolts.. ( you can resharpen as you need with the dremel bit, plus reshape the bit with those little black stone shaper things).

[ClarkGriswald]

Got a comp gauge today, warmed her up then tested it.. recorded my results then put oil in each cyl then tested (individually, so the oil-test interval was the same. I think its actually starting to get a tad better like topkat suggested as far as rings seatin in. Got 100 miles approx on it so far. I suspected one stronger cyl on the right side sure enough the results show a trend leads me to think valve adjustment might do it. My next project is to get the cam cover off and check em.. but heres the stats .

Numbers are before and after putting oil in the cyls..

#1 109/115
#2 110/125
#3 106/115
#4 135/145

Looks like #4 was the one Ive been hearing as higher in the mix.

[Jerry]

Build date is always the year before the model date. My '82 XJ was built in '81. Factory has to build them and get them to dealers for that model year, so '78s were built in '77 and so on.

Some states title bikes by year sold, so there are some '83 and '84 US XJs, even though yamaha didn't have them in the lineup those years.

Some very strange title laws in the US, but having a build date 1 year earlier than title date is right for your XS.

[thewiz]

"..the results show a trend leads me to think valve adjustment might do.,."

Well I surely hope that it does .... but I don't think the results of your comp. test indicates that. A cam chain and valve adjust always sweetens up the motor. Yamaha tool ... -01245 works like a charm, Makes it easy

If it were me, I might try an oz of MMO down each hole and then roll the motor over by hand a few times to slosh it around in there. That stuff disolves carbon almost before your eyes... no foolin'. Well ... overnight anyway

[cruiser]

Just to add a note about your compression check. Did you have the throttle wide open when doing the test? Makes a huge difference.
Don't ask me how I know

[ClarkGriswald]

Yep throttle was full open, Just drove it down the street. ran pretty good, mabye some of that oil is still in there helpin hehe..

For the life of me I cant find my feeler gauge, I oiled em and put em in a little plastic bag years ago and apparantly stored em in too safe a place. Oh well at least they arent rusty and stuck.. I think