XR650L rebuild – OLD Bull Trailriders

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February 18, 2013 at 1:11 am #102408

Nick Dole
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Had a XR650L engine come in for a rebuild. Think it’s an OB member, Mark Taylor,anyway I’m sure Mark will identify himself as the avatar thing does my head in.
Standard problems. Was running fine, then it just locked up, not sure why.
I asked my standard questions. “Did it have any oil in it?” Standard reply “Yes, I’m always really careful with my oil/checking/changing.”
Sad fact is, if your engine is getting a little long in the tooth oil consumption can creep up on you. if you get low on oil you will wipe out and engine faster than an cat can lick it’s backside.

February 18, 2013 at 1:15 am #236911

Nick Dole
Member

Burnt 2 rocker arms at top, bottom ones are normal wear.

Right cam lobes are burnt from lack of oil, left ones are normal wear.

February 18, 2013 at 1:18 am #236916

Nick Dole
Member

Pretty normal looking piston that has been oil starved.

Bore has some piston stuck to it, that’s the alloy looking streaks.

February 18, 2013 at 1:28 am #236917

Jeffrey Smith
Member

I was just saying to TB on the weekend that I hadn’t heard what happened to MT’s engine. I was with him when it died and had to tow him up the road.

February 18, 2013 at 9:16 am #236918

Mark Taylor
Member

Jeffro wrote:

I was just saying to TB on the weekend that I hadn’t heard what happened to MT’s engine. I was with him when it died and had to tow him up the road.

Yeah Jeffro. It’s been awhile between tows, Spoke to TB tonight and it doe’snt sound to good. So my good boss has lent me his Tiger and i am off to The Island to watch a bit of racing.

When the old girl is back going maybe you might ride with me again and i should’nt need a tow and pack service. Cheers

MT

February 18, 2013 at 9:53 am #236930

Jeffrey Smith
Member

MT wrote:

Jeffro wrote:

I was just saying to TB on the weekend that I hadn’t heard what happened to MT’s engine. I was with him when it died and had to tow him up the road.

Yeah Jeffro. It’s been awhile between tows, Spoke to TB tonight and it doe’snt sound to good. So my good boss has lent me his Tiger and i am off to The Island to watch a bit of racing.

When the old girl is back going maybe you might ride with me again and i should’nt need a tow and pack service. Cheers

MT

Yeah mate, any time.

February 18, 2013 at 10:00 am #236937

Mick D
Member

He is lucky that the centre slipper bearing for the cam is still ok. I have seen a few XRs that have starved for oil chew into the head.

February 18, 2013 at 10:16 am #236942

Nick Dole
Member

You are not wrong Mick. Engine seems to have survived it pretty well. Piston pin is welded in the rod though.
Gearbox looks ok at first glance too, no hard facing missing.

February 18, 2013 at 12:26 pm #236945

Mark Taylor
Member

Teknik wrote:

You are not wrong Mick. Engine seems to have survived it pretty well. Piston pin is welded in the rod though.
Gearbox looks ok at first glance too, no hard facing missing.

Nic i’ll catch up when i get back and hear all the bad news.

In the mean time i will be off line for awhile and having a well earned break.

MT

February 18, 2013 at 12:48 pm #236959

Nick Dole
Member

Ill have it quoted up for next week. Will look for a stock cam in my spares too, you don’t want any if the 3 monsters I just had ground.
Will go with a stock type piston too, the Wiseco’s are no good for adventure bikes, ring life is crap.
Might see you at PI.

February 20, 2013 at 12:31 am #236960

Kent Duncan
Member

Teknik, you recommend using the stock piston for an Adventure bike?

You mentioned “stock type”, just trying to clarify if its an OEM piston you’d prefer or an aftermarket billet version machined to stock specs?

Do you apply the same train of thought to the 650R as well?

Teknik wrote:

Ill have it quoted up for next week. Will look for a stock cam in my spares too, you don’t want any if the 3 monsters I just had ground.
Will go with a stock type piston too, the Wiseco’s are no good for adventure bikes, ring life is crap.
Might see you at PI.

February 21, 2013 at 9:35 am #236995

Nick Dole
Member

I don’t like using the Wiseco type rings in an air cooled engine. In my experience the oil rings loose tension after not that long and the blue smoke on start up is not acceptable for most people. Usually under 10 000km and they start smoking. The OEM rings won’t do that till 60 000.

As for cast vs forged I have never seen a stock XR piston fail prematurely from excessive RPM. I also don’t like the extra clearance you need to give a forged piston as it makes the engine noisy and that’s not what an adventure bike needs. What kills XR pistons is lack of oil.

To achieve higher compression I can get a stock piston up to 10:1 and I don’t advocate any more is better as the air cooled engine detonates easily if it gets hot.
I will run a slightly bigger cam than stock but it needs to be on a Honda core to retain the auto decomp. The starter is worked too hard with a hotcam stage 1 no decomp.

February 21, 2013 at 9:42 am #237058

Nick Dole
Member

650R is the same. I had JE make us 11:1 pistons with OEM rings pin and clips. That’s what we used in 00-05. I ran out of them and never re-ordered because the HRC piston had become more common and not horrendously expensive and so many people with no idea (my opinion) told me the Wiseco rings were fine.
In the odd 650R engine I do now the customer has usually bought a pile of expensive billet junk from the US of A and wants me to assemble the mess. I smile, take their money and do the work. They don’t ask my what I think, some expert has already told them.

February 22, 2013 at 12:10 am #237061

Kent Duncan
Member

Thanks for the info Nick, very informative.
Would you recommend the use of the stock cam (lift/ height) over a modded stock cam in an adventure bike?
Obviously we’re not looking for extreme power etc, more so fuel economy/ rideability. Is there a particular grind you use for ADV style riding or one size fits all?
Appreciate the reply’s due to your expertise.

Teknik wrote:

650R is the same. I had JE make us 11:1 pistons with OEM rings pin and clips. That’s what we used in 00-05. I ran out of them and never re-ordered because the HRC piston had become more common and not horrendously expensive and so many people with no idea (my opinion) told me the Wiseco rings were fine.
In the odd 650R engine I do now the customer has usually bought a pile of expensive billet junk from the US of A and wants me to assemble the mess. I smile, take their money and do the work. They don’t ask my what I think, some expert has already told them.

February 22, 2013 at 10:14 pm #237094

Nick Dole
Member

Stock cam is usually pretty mild/conservative. The cam we used to use in Enduro XR600’s is not much bigger than stock and has a little more lift but gives a nice increase all over, hence it became known as the “all round” grind. No problems with using stock springs/valves/retainers too. That’s what I’ll use in this engine. The stock 600 cam is fine though, usually run it a couple of degrees retarded. Hedge used a stock cam/piston for every Safari in the 90’s so that should tell you something. They had a bunch of cams they could have used from Webb, Megacycle, HRC, White Brothers.
I can’t say for other bikes like the Tenere’s as not many people modify them.
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