Need some serious help

[XJLimited]

Hey guy's

Here's what happened, i'll try to keep it as brief as possible.

Bought a 83' XJ400 Special edition (YICS) 4 Cylinder in february, it ran fine for a couple of months until something strange started happening, the number 2 cylinder would foul plugs every mile or so, Nor it would take any rev's above the 3K mark, thought may be something had gotten into the carbs so took them apart & cleaned them as good as i possibly could but unfortunately to no avail. did the same procedure about 5 times until i gave up on the carbs & realized it aint the carb's & surely it wasn't. after swapping tci ignitions/pick up coils/Plug coils. i tore into the rear engine case to find the number 1 cylinder connecting rod with an inch of up & down play

Removed the damaged connecting rod to take a look at it's bearings & astonishingly there weren't any, just some sheet of metal was installed in place of the original bearings, why? i don't know.

How much damage has been done to the journals/connecting rod? i don't know but i'd like to only if i knew what tool's i'll need to do so & Probably get this engine running good again & that im sure will only be possible if guy's over here guide me through it. Dan Hodges, TopCat, trbig, ken talbot, Maximan. Just to name a few.

Currently the engine is packed, Since i did not had the expertise nor the time or resources to fix it at that time, so decided to put it back until i could find myself some & since now i do have some time, i was leaning to do it..

btw, Im aware this forum is mostly about the XS/XJ 1100's but since there aren't any other sites i could get help from regarding this particular procedure , i finally decided to post it up....

[mro]

number 1 cylinder connecting rod with an inch of up & down play

Not sure what level of machanical experiencce you have???
For a rod to have that much "play" it would need to be in more than one piece.

Can you post a pic of offending parts ?


mro

[skids]

Re: Need some serious help

I recommend that you take the discussion out of the forum area now that you have made your plea for help.

Originally posted by XJLimited

Bought a 83' XJ400 Special edition (YICS) 4 Cylinder in february, (snip)
btw, Im aware this forum is mostly about the XS/XJ 1100's but since there aren't any other sites i could get help from regarding this particular procedure , i finally decided to post it up....

[MacMcMacmac]

Umm, this IS the "Other Bike" section isn't it?

Anyway, if it's an XJ400 four cylinder, it's an import, since the smallest XJ sold in North America was the 550. Also, there is no "400 Special" four cylinder. They were all two cylinder machines, and XS's not XJ's.

So, I am guessing you probably have either an imported machine, or an XJ550.

Bearings may be hard to find for this machine, but you wan't to give it a try. You need to mic the bearing journal to see if it has worn oval, and if it is still within spec. If the inch of play was all in the bottom end, you are most certainly screwed unless you can find another crankshaft, or cases, if the wear is there. It might be a lot easier to just source another motor, rather than go through the bother of finding parts and doing the engine up.

[Ken Talbot]

Originally posted by MacMcMacmac
Umm, this IS the "Other Bike" section isn't it?

It is now, mac, I 'moderated' it over here earlier this afternoon.

[XJLimited]

Originally posted by mro

Not sure what level of machanical experiencce you have???
For a rod to have that much "play" it would need to be in more than one piece.

Can you post a pic of offending parts ?


mro

Scary the amount of play there was, not really an inch but scary enough to let one feel like. anyway's totally my bad. i'll certainly be taking some pics of the inside once i tear into the motor, which should happen once i get all my required tools in place.

I've worked on a few late '73/84 honda CB versions of the 175 & 185, so im hoping i can get through this slowly & carefully...

Originally posted by MacMcMacmac
Umm, this IS the "Other Bike" section isn't it?

Anyway, if it's an XJ400 four cylinder, it's an import, since the smallest XJ sold in North America was the 550. Also, there is no "400 Special" four cylinder. They were all two cylinder machines, and XS's not XJ's.

So, I am guessing you probably have either an imported machine, or an XJ550.

Bearings may be hard to find for this machine, but you wan't to give it a try. You need to mic the bearing journal to see if it has worn oval, and if it is still within spec. If the inch of play was all in the bottom end, you are most certainly screwed unless you can find another crankshaft, or cases, if the wear is there. It might be a lot easier to just source another motor, rather than go through the bother of finding parts and doing the engine up.

It definitely is an import, most probably from the european mkt. it's a 1983 XJ400 4 Cylinder (YICS) Engine. afaik these weren't brought into the us mkt for some unknown to me reason.

I can source the correct bearings once i know what color/coded bearing i'll precisely be needing, but importantly that's only once the crank is confirmed to be usable & within spec. if otherwise i'll just get rid of this motor & look for another, may be a 550, if possible.

1st priority really is to try & revive this one.

So the rest of the 3 Rods seem to be in good condition, whereas the 4th is missing a bearing, i was wondering if all 4 of the rods use the same coded bearing & if are interchangeable, cause i remember installing the number 3 cylinder rod bearings onto the 4th rod journal just to check it's spec & found no obvious play or movement, does this really mean anything?

[MacMcMacmac]

This is for a 550, but it might apply to your bike as well, since it is pretty much the same engine.

http://i31.photobucket.com/albums/c3...gselection.jpg

Oil clearance is between 0.00016" and 0.00025".

[TopCatGr58]

So the rest of the 3 Rods seem to be in good condition, whereas the 4th is missing a bearing, i was wondering if all 4 of the rods use the same coded bearing & if are interchangeable, cause i remember installing the number 3 cylinder rod bearings onto the 4th rod journal just to check it's spec & found no obvious play or movement, does this really mean anything?

Hey XJ,

They sell a measuring tool called Plastigauge, and you would want to use it inside the bearing cap and bearing, torque to spec...DO NOT ROTATE engine/crank, then just disassemble, and compare the size of the black stripe on the plastigauge, it will have enlarged by compression to a certain size, if too compressed, then not enough clearance, etc.! Then you'll be able to possibly determine whether you can just install a new set of bearings.

However, with it running loose like that, I would suspect some damage to the crank, don't know whether you would be able to get it machined/turned to allow use of an oversized bearing?
Good Luck! T.C.

[MacMcMacmac]

Check this out as well.

http://www.motorcyclespecs.co.za/mod...xj400%2080.htm

[fredintoon]

Hi XJ,
betcha I know what "sheet of metal" is.
A half-century ago young Mr. Stupid's BSA A7 developed a nasty knock but I rode it home anyway. The timing side rod end had what I too would have sworn felt like an inch free play but was actually only ~1/8". It too had a "sheet of metal" instead of a bearing that turned out to be the battered remnant of the steel backing of the whitemetal bearing shell. A micrometer check of the journal showed over .050" ovality.
But what to do? My local guy reground the crankpins but by the time they were round again they were 0.100" undersize and the biggest undersize shells were only 0.040".
So he poured the connecting rods with Babbit metal. I ran that bike another 10,000 miles and it still ran good when I traded it. But that was then. That technology no longer exists. Your best bet is to look for another crank & rods because yours are FUBAR.