XR 100 Engine Noise / Broke? / Help

[Gerrmarr]

I picked up a 1994 XR100 not running but it had spark and felt like good compression.
Cleaned the carb and got it to run - smoked a little. Took it to Hollister Hills for grandson to ride.
He said it felt low on power. My son and grandson took it to air up the tires.
A guy there said it sounded like the valves needed adjusting.
My son adjusted the valves (although we had done that earlier).
The engine was making a shrieking sound - like a dry bearing maybe.
I thought that maybe the oil pump wasn't working.

I drained the oil today and there was some small metallic pieces in the oil at the drain hole/plug
and the oil in the pan looked like there was some metal residue/discolorization.
I kicked the bike over and could hear the shrieking noise.
I removed the oil pump check bolt (near the spark plug)
I oiled the top end/rockers/tappets and shot oil in the oil check hole.
The shrieking noise went away when I kicked it over.

I pulled the stator / flywheel cover.
I noticed that the flywheel had about 3/16" in-out free play.
I'm thinking that is too much.

Any suggestions on what my next move should be would be greatly appreciated.

Thanks,

Gerry

 

[Ol'89r]

You may want to pull the top end and check the camshaft. If you were not getting enough oil to the top end, the camshaft could be damaged. When you remove the head nut with the copper washer on it, oil should come out when the engine is running. That stud feeds oil to the top end. Also check the cam chain adjustment.

 

[Gerrmarr]

Thanks for the reply Ol'89r! I have a couple of dumb questions. Do I need to pull the engine to pull the top end? Do I start the engine with the head nut with the copper washer removed to verify that oil comes out? Is this safe?

Thanks. As you can tell I haven't ever worked on the internals of a motorcycle engine. I did notice that the cam shaft sproket had one shiny bolt - which tells me a previous owner may have replaced it. Do you think the 3/16" flywheel freeplay is excessive? I like your quote!

Gerry

 

[Ol'89r]

You can do the top end with the engine in the frame. When you check your oil pressure, start the engine with all head nuts tight. Then, while the engine is running, loosen the nut with the copper washer on it and oil should come out of that stud. If is doesn't you may need a new oil pump or you may have a blockage somewhere in the oiling system. You only crack the nut for a few seconds to see if you have oil pressure.

Not sure what you mean by 3/16" flywheel freeplay????

If you don't already have one, you may want to buy a service manual. It will have all of the proceedures and specs for working on your engine and will help you understand the inner workings of your engine.

 

[Gerrmarr]

Thanks Ol'89r. I tried to remove the flywheel to checkout the in-out freeplay, but I couldn't get the flywheel nut to loosen (I know it is a left-hand thread). I was using a rubber-strap device to hold the flywheel from turning, but that wasn't strong enough. A fellow from another site said there should be no freeplay.

This engine has no copper washer. The previous owner(s) may have done an incorrect rebuild. I assume the oil stud in question is the right rear as viewed from sitting on the bike. I did remove it (is 14 ft lb torque correct?), as well as the oil passage check bolt above, right, of the spark plug, and I didn't see any oil come out while the engine was running. I made two seperate checks. Another site said the oil passage could be blocked if someone used form-a-gasket type cyclinder gasket. If so, is there anyway to run a wire down the passage to unblock it? I'm thinking that it probably isn't possible unless I dismantle the engine.

I assume I need to open the cases if the oil pump needs replacing. Are oil pumps available through aftermarkets or only Honda?

Also, is Clymers the best manual available?

Does anyone know of a good shop near the San Jose, CA. area where I could get the engine worked on?

I have another XR100. I'm thinking of pulling the valve cover to see what the oil pressure looks like on a good engine.

Thanks one and all for the help! It is greatly appreciated!

 

[Ol'89r]

There should be very minimal side play, 3/16 is way too much. You will need a flywheel puller to remove the flywheel. You can use an impact wrench to remove the nut. You can also put the bike in gear and lock the rear wheel to hold the flywheel while you are removing the nut.

I can't remember which stud is the oiling stud. It is either the top right or bottom right side stud. The oil should come out immediately when you crack the nut. If it doesn't you have a problem.

If I remember correctly the oil pump can be replace by removing the right side clutch cover and clutch assembly. Check out the Service Honda link on the left side of the page for a good parts source. They also offer a discount. OEM parts are best IMO.

Clymer manuals are ok. Factory manuals are best.

Can't recommend a shop in SJ but I can refer you to a great machinist in Petaluma if you need any machine work done.

Not sure how mechanical minded you are but, if it were my bike, I would purchase a good manual and then remove the engine from the frame and tear it down. They are not that hard to work on and you can send your cylinder head and cylinder to my guy in Petaluma and he can rebuild them for you. You probably have excessivly worn main bearings causing the side to side clearance and most likely a cooked camshaft and rocker arms due to the lack of oil to the top end. Check out www.Edco.com in Petaluma for your machine work.

Sorry, that edco link does not work. I'll try to find a link that works.

 

[Rich Rohrich]

Here's the link you need 89r
: http://www.enginedynamics.com/index.html

 

[Ol'89r]

That's the one. :cool: Thanks Rich.

 

[pesky nz]

I think you may have the models mixed slightly ol89r xr100 has one piece valve cover hiding the head nuts on later models and 2 round covers on older (1970ish) model that looks similar to xr200 with exposed head nuts. Lots of both models I've seen inside have a lot of main brg side play in cases and while not perfect they seem to last, but I'm sure they wear the cam chain area sooner. Both types have an oil screen under the clutch cover I think and these are prone to blocking after a cluch fibre melt down. The older style also has an oil screen under the large round plug on the lower left side (23 or 24 mm head size). Oil pumps are under the clutch cover on both models, all from memory not manuals so I hope this helps

 

[Ol'89r]

I think you may have the models mixed slightly ol89r

You are correct pesky, thanks. I was thinking of the early design. I didn't notice the 1994 at first. I was doing it from memory too. That's quite a feat since I can't even remember what I had for lunch yesterday. :coocoo: Between the two of us, we'll figure it out for the guy. :cool:

 

[pesky nz]

Bacon sandwiches, it's the same every day for me, taste over cholestrol every time. Yep it's all about helping to keep people riding

 

[Gerrmarr]

Thanks old dudes! I'm only 65! I got a Honda service manual and removed the right side crankcase (clutch) cover. But before that, I loosened the "oil check" bolt on my other (good) XR100, and the oil did flow very well - with the engine running.

So back to the problem child. The manual says to remove the OIL THROUGH (prior to removing the oil pump. Well, guess what? No Oil Through! Not sure if the previous owner(s) left it out or it fell out and got ground up? There is also a spring that goes with the Oil Through. So, I guess I will order an Oil Through and Oil Through Spring. These parts are about $10 + shipping from BikeBandit.

I want to check/clean the oil screen. It's hidden beneath the Right Side Cover gasket. I would like to save the gasket - it seems to be 'stuck' on the lower part area where the oil screen is located. I was thinking of cutting the gasket with an xacto knife to expose the oil screen hollow. Is this a good idea? All this to save $14 on a new gasket!

Thanks all for your helpful comments!

 

[High Lord Gomer]

Only 65? 89R has habits older than you!

I think you know the result of trying to reuse that gasket if it is already torn. I have had success reusing gaskets but I had to put them on with grease the first time so they wouldn't stick.

 

[Gerrmarr]

XR100 update: Thanks guys! I got a service manual and removed the right side crankcase/clutch cover. No Oil Through! Hopefully this explains why no oil is getting to the topend. I will order parts (oil through and spring), install, check for proper topend oil flow and report back. Gerry

 

[holeshot]

Only 65? 89R has habits older than you!

.

89R wears a habit? :whoa:

 

[High Lord Gomer]

Only on Saturday nights following a full moon.

...or maybe it was Occifer Elkarello's moon that he follows...

 

[Ol'89r]

Jeeze!!! Damn kids anyway. :yell: GET OFF MY LAWN. :nener:

 

[Gerrmarr]

Ok. I'm waiting for my parts - the oil through and spring. The spring is on back order - should take 4 days longer.

I have a question about oil. A guy who bought my '09 CRF100 said he had a friend who broke a fan belt on his VW based engine during a Baja type race, and finished the race without fan cooling. He swears it was because the guy was using Mobile 1. So now he puts it in all of his dirt bikes (4 stroke, I assume). He says it doesn't appear to harm the clutch plates. What do you guys think? Is Mobil 1 good for 4 stroke motorcycle engines? It seems to work ok in my '98 Corvette - 94K miles and no problems (although I'm not hard on this car/engine). I saw a YouTube video about motorcycle maintenence, and the guy swore by Motul. Any comments?

Big G

 

[High Lord Gomer]

"What oil" is a religious topic and is therefore not allowed here.

...but I will tell you God runs Mobil 1 in his CRF450.

 

[truespode]

Rotella!!!

 

[Ol'89r]

Gerrmarr. Everybody has their preferences when it comes to oil. Mobil 1 is very good as is Rotella. Some say diesel oils like Rotella are better because they still have sulphur in them. sulphur is easier on valves. sulphur has been taken out of most all automotive oils including Mobil 1. Mineral oil like Castrol GTX is a good oil if you don't want to pay the extra money for synthetic. The main thing to remember regardless of what oil you use is to change it often. Keep the oil clean and change the filter every time you change oil. :cool:

 

[High Lord Gomer]

Now that is just crazy talk! You told me I only had to change my filter as often as you change your shorts.

 

[Ol'89r]

Now that is just crazy talk! You told me I only had to change my filter as often as you change your shorts.

Waddayou talkin' about??? :coocoo: I change them once a month weither they need it or not. :fft:

 

[holeshot]

Waddayou talkin' about??? :coocoo: I change them once a month weither they need it or not. :fft:

Sounds about right - they both filter dirty air. :nod: