1981 XT250 rocker a weak point

[mcferreira100]

I have heard a weak point on these bikes is the rocker arm wears prematurely causing wear on the camshaft as well. This can cause bike to miss as exhaust valve not operating properly...which is what I`m experiencing. The engine is out and will take a look but can anyone offer advice on this fix..has anyone encountered same problem?

The cost to replace these items must be horrendous.

[YPVS TONE]

Hi mcferreira 100

Just found an old Yamaha Technical Service Bulletin that was sent out to Yamaha dealers here in the UK ref XT250/SR250 Excessive Camshaft Wear. It say's

" If you experience any problems with camshaft and/or rocker wear we request that in addition to replacing the worn parts you also replace the following:-

(i) Oil seal 93101-14092 (shown in picture as oil seal on inside of RH engine case just below oil filter housing)

(ii) Housing, rotor 3Y1-13336-01

Gear, pump driven 3Y6-13326-01

Rotor assembly 3Y1-13310-01

Please also check the cylinder head oil passage (shown in picture as oil feed to the camshaft) to ensure no swarf is blocking the oilway.

When assembling the engine the new camshaft and rockers must be smeared with molybdenum oil (STP or similar) or molybdenum disulphide base grease. If the camshaft has no oil supply, even for a few seconds, when the engine is first started damage will occur which will not become evident for several hundred miles".

Hope this is of some help

Tony

[mcferreira100]

Thanks YPVS..that is a scary bulletin. These parts will cost arm and a leg. WIll have to do a South African "boer maak a plan" repair.

[10rdmag]

If this helps, I had the same issue on my 1983 XT250 the CA Model. Parts if available are scary expensive. I had a bad rocker and camshaft...took a chance and found a cam from a 1982 TT250 and fit & worked just fine.