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-   -   XR650L dropped valve Tunisia (https://www.horizonsunlimited.com/hubb/honda-tech/xr650l-dropped-valve-tunisia-8756)

POB/London 29 May 2004 19:04

XR650L dropped valve Tunisia
 
Ah, the nightmare that is my relationship with this bike continues. Riding an easy Rallye Tunisie piste just outside Douz, I stopped in a very soft patch.

On restarting, it sounded like the bike had a really badly adjusted valve - with the old screwdriver-to-head trick I narrowed it down to the l/h exhaust valve.

Limped back to campsite (with a helpful quad doing route-finding) and opened the valve cover to find 5mm of play and a valve that looked stuck in the open position.

Spent the evening removing carb & cam cover. All rockers etc look brand new. Valve tops look OK. This morning I removed the head and the valve seat has broken, and chewed the ally and the end of the valve.

I reckon the valve is still straight, but I obviously need a new seat & for it to be reground, as well as more aluminium welding into the head and a new hole milled.

I`ve had the head sent to Sfax to be repaired today. Obviously I`m not happy but the guy has told me that they have to do this to old Peugeot lumps all the time.

There was nothing amiss with the engine before this - it was full of good European oil and only 4000kms old (since a full rebuild). I was not running hot - between 150 and 200 F.

Be careful folks. I can see no way I could have prevented this, and it may amount to a serious design fault, being such a new engine.

http://www.horizonsunlimited.com/ubb/frown.gif

------------------
=-=-= ON THE EDGE! =-=-=
My XR650L Pan-Med Expedition Site!

:)

RichLees 30 May 2004 18:26

sorry to hear it, Lewis, but I'd guess it was either random or to do with the tune-up and then seize and rebuild. can I take it you are no longer running that hot cam?
in my view/experience, the engine is generally unburstable on this bike.
let me know if you'd rather have a second hand head sent out. I think I could find one quickly enough and I guess you'll be needing a new gasket too.
all the best
Rich

POB/London 30 May 2004 21:58

Hi Rich -

No hot cams here! Internals were totally stock, but you might be right about the history; it was running very rich (overjetted) for a while.

Now is mildly hopped up with a pipe and filter, and possibly the same jets as you (170 main). I suspect it will remain a mystery - although the combustion chamber was very sooty the plug & tip of exhaust are a healthy grey.

The head came back today: a fairly scruffy bit of ally welding but the guy assures me they fitted the new Honda seat properly. I also had to have a recon valve, as the stem was bent. I will take all old parts with me I reckon, and I will check everything is torqued up & in the right places before leaving town. Toying with the idea of a just-in-case oil change too (but only have 2L of decent Euro 20-50 with me).

Next decent mechanic will be in Cairo, so I`ll just have to take it easy until then - although I still have some Rallye and CS routes to do here. If you could keep that offer of the 2nd hand head open till I have the thing checked in Cairo that would be fab.

I can be contacted by text (best) on +44 (0)77 1314 8532.

Cheers. All being well off to Chenini, Matmata and Ksar Ghilane tomorrow, then Tataouine.

Has been impossible to upload to web from here, basically only incoming + email.

[This message has been edited by POB/London (edited 30 May 2004).]

POB/London 4 Jun 2004 02:47

Bike all good, touch wood.

Not using any oil or even running hot. Have done 260+ kms of pîste and off-piste (all piste solo, some very duney because of storms in last week or 2) with not so much as a sputter. I agree with Rich about this bike - it takes some prepping but once its done its a belter! Drifting a loaded overlander and enjoying the odd bit of air has been a blast! Even on soft virgin sand (with airless Deserts) ... amazing.

Am now in Ben Guerdane on the Libyan border. Still no word on invite though, although the gents in Tunis are standing by... If not, then bike goes by sea (Sfax to Alexandria) and I get an extraordinarily cheap flight from Djerba to Alex (price I was given today was 230TD return). Sounds like a lot of hassle I know, but it looks like you may just be able to cruise into Libya by next year, and I will def. come back. On a side note, everything that Budrinna (sp?) says is contrary to what people have told me at the consulate and here on the ground...

Other problem was 35mph get-off on the beach yesterday (curse you for giving me the idea Geoff!) I arrived in B-G and decided to look at the sea for the first time in a fortnight of summer desert. Suffice to say that desert sand finesse does not work on algae-rich coastal salt flat. Leg is black & blue despite MX boots (take note) and all bike switchgear knackered. RH box also got ripped off (thank you Touratech) and was mended - actually improved - for a quid in town... A bit of a lesson there...

Sorry for waffle but no updates to site (bandwidth and blocking problems here) despite some amazing pics and experiences, including the dream scenario of being taken in for a full-on Berber welcome in the middle of nowhere.

BIKE LESSONS:

Get H-D wheels, including spokes, Deserts, H-D Bridgestone tubes, Slime and rimlocks. Sod balancing but check bearings B4 leaving - they have a hard time here.

Fit an oil cooler. Check oil at every fuel fill and after the first 30 mins of riding each day. Get into the habit of checking the dipstick temp regularly. In ambients of 40+ my bike has always been in 200-250F range.

IMO is great for checking charging with toys all plugged in. Also v.useful for plotting fuel stops and calculating economy, as well as the ace arrival time estimation gizmo. Great for amusing locals and diverting the attention of officials too http://www.horizonsunlimited.com/ubb/wink.gif

Make sure handguard mounts are tight, but levers are a little loose, and consider leaving one mirror at home.

DIY large footpegs = fabulous idea. Likewise for sheepskin (ta Geoff and Ikea) and DIY mini-fairing.

------------------
=-=-= ON THE EDGE! =-=-=
My XR650L Pan-Med Expedition Site!

:)

RichLees 4 Jun 2004 03:48

glad to hear you're on your way again. what happened to the valve? did the stem break or collets come out?
I'm with you on many of your tips, but not the HD wheels, 0 psi or out-of-balance. I balanced the standard wheels and ran them at 22psi front and 28psi rear. maybe I was riding lighter than you, but I didn't bog once. I'm not saying it glides over the sand, but it saves pumping up for the rocks! balancing helps avoid losing strength and bolts due to vibration
enjoy the rest of it!

POB/London 6 Jun 2004 18:31

OK, you got me on a couple of issues...

By empty, I meant 18psi rear & 15psi front. With 4mm thick inner tubes, that meant 70km/h rocky pistes and sand were both possible. There were some big hits on the front wheel, which made me wince a bit, but all held up very well. Using my compressor (ha!) I put them right up to 30 front and 35 rear for the road.

I didn't get the wheels rebuilt - the previous owner did. They are stock rims and hubs, but with Talon spokes. Nothing has ever needed serious attention in over 2 years of abuse, and the folks at Talon were ace when I wanted some spare HD spokes and nipples to take away with me.

Also on the subject of the wheels - how did you ever balance them? With rimlocks and Deserts it's almost impossible, requiring crazy numbers of weights! If there's a trick to it I'd love to know - I don't want premature bearing failure!

Bought a new rear Pirelli Enduro Pro something or other today (looks v.like a desert, also available here on blqck market) probably pinched from a Rallye support truck: brand new for 40TD!

RichLees 6 Jun 2004 19:06

my rim locks weigh 60(?) grammes so you need that much on the other side! forget the tyres own imbalance or you'll be trying to refit it in the same position if ever you do get a puncture. I tried all sorts of pressures to try to preserve rear tyres and settled on 28. let us know how the 35 affects wear.

[This message has been edited by RichLees (edited 06 June 2004).]

Oz 26 Aug 2004 08:14

am presently on a dommie which has just dropped its valve seat for the second time in 10,000 miles (vancouver first and now quito)some mechanics i have talked to along the way say they have seen this before in this engine, all reckon its down to overheating and suggest fitting a temp gauge. if i am right in thinking your engine is very similar to mine be rest assured you aint the only unlucky person out there. i am just hoping i can get another 10,000 out of the bike to see me to tierra del feugo.
good luck
oz

Stuart Jenkins 28 Aug 2004 04:30

I've been speaking to the guy at "the cylinder head shop", and he's had quite alot of the Honda rfvc heads in with dropped valve seats, a common trait with these by the sounds of things. As there isn't much metal between the seats, cracks can develope in the ali, heat expansion allows the seat to drop.

My XL head is in dire state (as is the rest of the engine!), with a couple of cracks between the seats, and valve guides need replacing. He told me he can weld the cracks up and grind them back, fit new guides, but warned that the seat could still "let go" in the future, and with the money spent on the bottom end, i don't fancy all that getting wrecked!! but getting new seats put in would cost nearly as much as a brand new head over £400 ouch!!...

I'm searching for a second hand head, but even then you can be in the same boat...the words money and pit spring to mind.

Happy riding

Stuart


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