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Jeffro contacted me before the B/D ride and asked me if I would like to rebuild the engine on his 1995 model Tenere. Of course I jumped at the chance so he bought it up to the ride and I took it back to the workshop to commence the operation. Jeffro mentioned that it was a little tired as it had 82000km on it and was starting to use a little oil. As far as we knew it had not had a complete top-end rebuild with a new piston and rings etc.
Tenere ready for rebuild.
Stripped of fuel tank and body work
Engine Out
Cylinder Head Off
After I removed the cylinder head I then measured the bore only to discover that the bore was 0.020′ oversize already, with a very glazed bore. :ohmy: With the standard bore being 100mm it was then time to see if a 0.040′ oversize piston was available. Bingo! A new 101mm forged piston was ordered as well as a top end gasket kit. I had a sneaking suspicion that this engine had been apart before when I noticed that some bodgy prick had tried to pry the cam cover off only to break a piece out of it and then proceeded to use Devcon or something similar to repair the damage. :angry: As you can see below.
I will try to get this welded and then re-machined for a proper repair.
More Later…….
Cheers,
Lefty
Trailboss wrote:How that crack didnt leak Lefty is amazing bloody good bog job :laugh:
TB
Going by this pic, I think it was leaking a bit.
He said it was leaking but as I have never had the fairings off (or done any work to it at all for that matter, not even an air filter clean or change
:blush: ) I didn’t see it.I got the head away today and I am hopefull that it can be welded. :unsure: The head will also be serviced with new valve stem oil seals, valves and seats cut if required and then surface ground. I am now just waiting on the piston and gasket kit so I can get it bored and honed.
As for the lack of low down torque bones compression is a good start, however I never rode the bike so I can’t really comment. That particular model has relatively low compression standard at only 9.2:1 Hopefully I can get the comp a little higher to give it a little more bottom end. The other thing that this model has is a dual throat carburettor with a vacuum secondary which may require a service also.Cheers,
LeftyJust an update on the TENERE..
Waiting on a Piston Kit from the US, then it can be bored and honed. Will check on the head service and welding tomorrow.
Cheers,
Lefty
Lefty and co….not knowing much about anything but my question that I am thinking ….
is are you worried about the bottom end?
like it has had the top end before so…….hows the engine bearings :dry:
do these bikes have a reputation of bullet proof bottom end?
or do you ride along as far as you dare…100km or 120kms and wait for the dreaded engine knock to develope? :blink:
or does jeffro want to sell it soon after…look really it’s none of my bussiness and I shouldn’t ask such questions but I have asked it anyway.
dude
No worries Dude, a legitimate question.
I am like you in that I don’t know much about anything either which is why I got Lefty to do it in the first place
so he is better to answer this than me but,,,,,,,,,,,,As far as the bottom end goes I have left that to his judgement. I just asked him to pull the top off to start with and see what’s needed from there.
Whether or not I keep it remains to be seen as I have a bit of a history of changing bikes regularly but I have no plans to sell it at the moment.
Dude, that is a good question that you ask.
I have struck a few issues along the way with the BIG TEN. Firstly the oil leak from the cylinder head which was then found out to be a huge crack in the cylinder head rocker cover from a previous “Bone Head” who had tried to remove the rocker cover with a tyre lever and broke it :angry: and now it requires welding and machining.
Then there is the flywheel; I actually broke 2 pullers trying to remove it. I then took the complete engine down to a Yamaha dealer and asked him to remove the flywheel which he could not remove it without firstly risking damaging the flywheel and a high probability of damaging the crankshaft. :ohmy: Which took me a complete day.
It was after these issues that I decided to leave the bottom end as it is. It measures up well within Yamaha’s Specs as far as I can measure, and unless Jeffro has an unlimited budget I am not prepared to risk a possible crankshaft and flywheel as well as the additional labour costs.
As for the bottom end the way that I look at it. The bike is a low revving low comp engine designed to do big kms. And yes while the bottom end looks and feels fine there is no doubt it could fail; however it looks like it has been well looked after and on completion of the rebuild I would not hesitate riding the bike to Perth and back.
Yes sure the clutch an gear box has also done many km’s, but where do you stop? Short of getting a complete new engine and drive-line assembly. :huh:
After the completion of the rebuild I will do between 300 to 500km to run the new engine in, replace the engine oil and filter and then Jeffro will receive the BIG TEN back ready for any Adventure. :woohoo: :woohoo:Thanks for asking.
Cheers,
LeftyThanks for the responce….so ok you had a go.
I was just hoping to see the insides of one of these beasts
Good luck
dude
I have finally got all the parts back and have re-assembled the big Ten.
I installed a 101mm Forged Wossner Piston, which is stronger and lighter than the std cast unit.
This now brings the capacity up to 673cc
509gms V’s 535gms (Improves response)
Piston Installed in the barrell bored and honed to specs
Cylinder Head serviced, machined and welded
Ready for another Adventure
I rode the big Ten today for the first time and put around 30km on her, then got back to the workshop for a check-over. I am really happy with the end result as she has plenty of torque as well as power when you start to open her up. I only just touched 5000rpm and it feels great. The only thing now is that it needs a carburetor service which, if I have time I will do this tomorrow.
More Later!
Cheers, Lefty
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