A forum for owners of Yamaha TTR250 trail and enduro bikes!

TiTeR250 · Member

Hello All. TiTeR250 signing in!

ttr steve · Super Guru

If you need a complete replacement engine, I have one available.

Steve

TTRfan · Super Guru

Hi George and welcome to the forum. Great introduction biggrin

In terms of your engine, the cost and benefits of rebuilding your current motor has to be weighed against the quality and longevity of a complete replacement engine unit.

The advantage of rebuilding your own engine is that you will know absolutely what has been done and which parts have needed repair or replacement. And you will have had the fun and satisfaction of doing the work yourself especially bearing in mind your experience of spanner twirling and the help available on the forum wink

The downside of buying in an engine is that, whilst the seller might be completely honest and can guarantee the engine being sold is working well and totally reliable, it is unlikely that it will have been rebuilt recently and so there could be a variety of issues that could arise which, being totally fair, are in no way the fault of the seller. If you decide to go this way then Steve at Totally TTRs is probably about as trustworthy as you can get biggrin

A complete working engine (less carb and starter motor) that you could hear running and test ride, could cost in the region of £800-900 - more if it has the highly desirable kickstart fitted.

You could of course recoup quite a lot of that cost by breaking your old engine and selling the parts - just the good ones obviously smile

Brian

TiTeR250 · Member

Hello Steve and Brian,

Thank you for welcoming me on board.

Well to be honest Brian, I'd love to delve into the engine BUT you're dealing with a 54yr old KID who just wants to get on and ride as opposed to staying in to do some 'spannering'. Especially that the weather is still in our favor!

Steve, you'll be pleased to know that I've already purchased some items from you. Most recent was a starter - bush - base - plate - thingie - wotsit and a few other bits 'n' pieces.

The real issue (in my mind) is that I may not be able to open the engine engine unless I take it to an engineers workshop and that, may cost me more than a replacement I can actually open and refurb!

George.

TTRfan · Super Guru

TiTeR250 wrote:
The real issue (in my mind) is that I may not be able to open the engine engine unless I take it to an engineers workshop and that, may cost me more than a replacement I can actually open and refurb!

Is that because of the rounded heads on the head bolts? If so, they are already ruined so you have nothing to lose by trying unconventional methods to undo them wink

I assume it's just the two outside bolts causing trouble? The two under the camshafts can usually be relied upon to be OK. The bolts also have an Allen head and maybe can be removed using a tight fitting Allen key socket?

In the worse case scenario, drill the heads off the bolts........

Brian

ttboof · Super Guru

I've just rebuilt mine as I could do it all my self it didn't take long and only cost about $550 aus

The gear box bearings are very cheap

A few gaskets and a top end rebuild is pretty easy

However if it turned out you need something like valves they are $96aus each mine were OK

And a mate did the rebore and head work

The head bolts that appear rounded off might just be a case of they are actually round as they are Allen headed bolts

Buying a good motor would be quick and easy and as mentioned the parts of the old one sell well

TiTeR250 · Member

Thanks Brian, I'll eventually have to grind all the heads off the cylinder head bolts as they are ruined. The placement for the Allen key is rounded off, and I'm quite sure that many of the screws securing the engine casing will have their heads shared off when trying to remove them (already lost a head on round cover that houses the starer gear)

ttboof, seem like I'm heading down the same route as you this winter!

ttboof · Super Guru

Take it easy and hopefully it will come apart OK overall there arnt many bolts to come out to dissemble the motor

Things like the starter cover I cheated and put anti sieze on them when the bike was new

My son took mine out today and is very impressed with the motor with the wosner 1mm os piston

And how it pulls as well as how smooth it is again

ttboof · Super Guru

Other than my usual tools and tension wrench these are the only extra tools I needed

5and 8mm Allen sockets and a bolt to remove the fly wheel (fits the rear axle nut ) and a bit of copper pipe to use as a gear jammer (not in pic as I lost it in the shed somewhere)

-- Edited by ttboof on Sunday 21st of October 2018 07:40:33 AM

OnTwoWheels · Member

Hello

have not had to do much on my TTR, but recently experienced some trouble with relatively soft metal Allen screws (some quite small and countersunk) holding flywheel and timing inspection holes dust free on a Ducati Multistrada I'd rescued from a disinterested owner. Dunno who supplies their fasteners, but not good. Aftermarket screws are hardened.

In desperation, discovered that slightly oversized (compared to the Allen) Torx bits from a reasonably cheap set acted quite effectively as extractors. Tap in and turn - x many repeats and occasional tapping the burring edges of the Allen screws flat, followed by more tap in & turn.

If you have the space and the tool, an impact driver which holds the torx bits securely will probably help quite a bit. Good luck!