broke down.

[bobberbetty]

ok. heres my problem.... broke down, thaught I seized my motor, due to piston rings ect ect. and when I got the bike to a safe location I checked the oil. I had an oil leak but I didnt think it was that bad, apparently I was wrong, becuase when I checked it, it was bone dry. went along with clymer book instructions. took off carbs, took off cam cover, removed cam sprockets and chain guide, removed cam chain, then removed head. cylinder walls are not scored, the only thing is, there is excessive carbon buildup on the tops of the pistons. then to instructions were to turn the timing plate so that the "T" is aligned with the stationary pointer. the problem was that I cant turn the timing plate to move the pistons at all. any suggestions on what to do next? or what the problem might be?


PLEASE HELP! Im desperate.

thanks,
Aaron.

[planedick]

Siezed bearings

Unfortunately, you have probably destroyed the crank and most, if not all of the rod bearings are siezed to the crank and you would be best to just find a new/used motor.

PS You shouldn't ride with leaks. Gotta fix 'em.

[olebiker]

Aaron, Dick is right. The engine is now cold and still won't turn it is toast.

[DiverRay]

You can verify the bad crank. Remove the clutch cover, remove the clutch plates, and THEN try to turn the crank. If it will now turn, the transmission is bad. If it still won't turn, See planedick's comment.

[trbig]

I've never done it with one of these, but I have seized up mowers before... and used them for years afterwards.

What you may try, and my suggestion will probably ruin the rotor which is easy to replace... is to pour some oil down on top of the pistons and let it sit. After a day or so, you can use a big pipe wrench on the rotor to try to get it loose by prying back and forth on it. You are going to need to get onto something more substantial than the timing plate "Bolt". You could try it on the rotor bolt first, but I doubt you'll get the leverage you need. There's a chance that only one of the inner cylinders (Since they usually get hottest) rings have seized to the walls. The bearings may have been getting a splash every now and then and be OK.

If you get the pistons to move, check for scarring on the walls. A slight hone may get it out if it's minor and you could possibly still use the motor.

Not trying to get your hopes up.. but I hate to automatically toss a motor.

If the lower bearings are gone, you may have ruined the head's cams and cam bearings also. Check that with some plastigauge before re-use.

Sorry to hear about all this. It's a reminder for all of us at your expense... check the oil. It only takes a second to look at that sight glass.

Tod

[bobberbetty]

yeah I checked the clymer and it said to get on the timing plate with a 19mm and it is actually a 20mm or a 21mm but there is no room to get leverage. so I will try to turn on the crank. if I do infact need to get a new motor does anyone know of anyone in my area to get a used motor?

[trbig]

These things tend to be like boats and motors. You can buy a whole boat with a motor cheaper than you can buy just a motor. You may be better off finding another whole parts bike.

Good luck.


Tod

[bobberbetty]

ok Im new to xs'. what year xs motors will fit my bike? with no fab needed?

[trbig]

Any of the years will fit. The ' 82XJ has the YICS system on the back of the head and cylinders, but would still work. You'd just use your elecrical stuff with it... unless the stuff that comes with it is better!


Tod

[TopCatGr58]

Hey Bobber,

Sorry to hear of your engine woes. You've got the 78E, saw it in your profile, but would be best to put it in your signature for future inquiries...tips and suggestions are often model/year specific.

The 78 has the 2H7 TCI/Black Ignition box, and uses both cent. and vac. advance modules...mechanical.

The 81 model uses a different 4Ro TCI and dropped the cent. adv. parts from the timing parts, and the 82 XJ uses a 10M TCI, and uses a different vac. sensor, and also no mech. cent. adv.

SO.....IF you find an 81, you can either swap the mechanical ignition parts from your 78E onto the 81 engine so you can use the 78's TCI, OR....IF you get a working 81TCI, you can plug it into your machine's harness. But it gets tricky because the 81 doesn't have/use the ballast resistor for the ignition coils. I'd need to review the wiring diagrams to see what if any mods would be needed to be able to use the 81 TCI.

Good Luck. T.C.

[AlanB]

Hi TC,

Ballast terminals are male/female, so the resistor can be left out and the two wires from the loom simply plug together.

A better solution would be to strip out the entire ballast circuit, but most of the bikes running aftermarket coils just use the bypass.

AlanB

[bobberbetty]

hey thanks every body for all your advice, not that it all makes sense but Im learning as I go and hoping I dont destroy my bike more than it already is. Im thinking the crank is destroyed after all, so if anyone knows of a very inexspensive crank for sale let me know. anyways thanks again.

Aaron.

[Ozmodius]

I have an 81 standard i'm parting out. The engine is good but 1st, and 2nd gear is slipping. SHipping a motor costs a ton, but since your in middle TN, and I live just south of Memphis we may be able to meet in the middle. Let me know if your interested.