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soggysod 01-13-2002 10:09 PM

xr 100 blown engine
ok just lookin for advice, i was doing a little work on my girlfriends 94 xr 100, just brakes tires and oil, and after i rode it to check out the brakes, about 30 seconds after i started it, it stalled, so i kicked it and it cliked and had no compression, so ipulled the engine, and pulled the head, the timing chain was off, and the valves were bent, o my question is why would the timing chain coming off cause the valves to bend and where could i get these parts cheapest? oh and at the oil change before the oil looked good no metal or anything of course after it had slivers in it but no chunks. oh is there anything else i should check i really dont want to have to tear the bottom end if i dont have to.

if it aint broke, break it so you can learn to fix it

**DONOTDELETE** 01-14-2002 09:48 AM

Re: xr 100 blown engine
Sounds like the cam chain tensioner was out of adjustment and it jumped it's timing. Check to see if the guide is worn out, it'll have to be replaced too if it is.

12208-413-003 SEAL, VALVE STEM (ARAI) 1 $7.87
2 14101-436-000 CAMSHAFT 1 $46.49
3 14431-116-010 ARM, VALVE ROCKER 2 $22.64
4 14451-035-000 SHAFT, VALVE ROCKER ARM 1 $5.09
5 14451-149-000 SHAFT, VALVE ROCKER ARM 1 $10.11
6 14711-152-000 VALVE, IN. 1 $20.22
7 14721-176-000 VALVE, EX. 1 $42.38
8 14751-149-000 SPRING, VALVE (OUTER) 2 $3.20
9 14761-115-010 SPRING, VALVE (INNER) 2 $2.73
10 14771-107-020 RETAINER, VALVE SPRING 2 $4.76
11 14775-107-000 SEAT, VALVE SPRING (OUTER) 2 $2.29
12 14781-107-003 COTTER, VALVE (SANKO) 4 $1.95
13 90012-333-000 BOLT, FLANGE (6X14) 2 $2.09
14 90206-001-000 NUT, TAPPET ADJ. 2 $1.24

**DONOTDELETE** 01-15-2002 04:20 AM

Re: xr 100 blown engine
Hi - I have fried a couple of those XR topends myself!! I discovered a long time ago (after cookin one) that Honda placed a small plug in the oil line feeding the topend of the small XR's so we could check the oil pressure after changing oil. The plug is located just above the sparkplug and requires a 10 mil socket to remove. I always remove this plug and kick the bike over until oil comes out after changing the oil - this removes any air and lets you know that the top is being properly lubed. Whenever I hear of a fried XR100 topend I always wonder if the top was being lubed properly. If no oil is being pushed out of this hole (if you start the bike with this pug out it will squirt big time!!) there is a oil pump problem CHECK THIS BEFORE YOU RUN IT AFTER YOU REBUILD IT!!! I buy alot of parts from Service Honda in Hammond Indiana, they are usually 30% under retail!!! If you cant find their number repost and I will get it for you.
Good Luck

**DONOTDELETE** 01-15-2002 09:06 AM

Re: xr 100 blown engine
The timing chain coming off allowed the cam to be in the wrong spot at the wrong time, allowing the piston to hit the open valves. If you see slivers of metal in the oil now you chould check to see if there is an oil filter in the bike. I bet it has some sort of centrifugal oil filter/screen that traps the big stuff, at least an XR200 does. The other guy is right, has cheap parts. Is your girlfriend mad at you? :)

soggysod 01-15-2002 07:40 PM

Re: xr 100 blown engine
yeah she's mad, but hey i bought the bike and i buy the parts so i just told her how it is. it does suck though, thanks for the help. no harder than she rides i will probably get valves and throw it back togeather. thanks for the help, oh anyone know how to set the timing on this beast!?!

if it aint broke, break it so you can learn to fix it

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