With a 'supposed' 90 hours on the meter I decided to check the timing chain, tensioner blades and the tensioner on my recently acquired '04 FE501. My first discovery was that the tensioner was within two clicks of fully extended, but that the chain and blades looked OK. The chain was no where near rubbing on the water jacket for example.
With neither chain service info or a new chain available to compare I couldn't really decide how worn the existing chain might be. Based on the fact that the motor doesn't look to have been apart I expected it to be the original JWIS (IWIS) factory rivetted item.
Having ordered a replacement IWIS chain and comparing new and old I was surprised to find that the newer chain had more side deflection than the old (see pic, new chain below old). I know this is very unscientific but it often gives an indication as to how knackered a simplex chain is based on link wear.
I then compared the chains lengths under load (20 KG) and was interested to find that the old chain was elongated by about 1.5 mm in comparison to the new. Interesting then that the older chain exhibits less side deflection but under load more elongation !! Not what I would have expected.
So, what's the point of all this? I'm not sure really other than to say that the original IWIS seems to have faired well over its 90 hours of use, and that simple assumptions can be misleading.
cheers
Dino
With neither chain service info or a new chain available to compare I couldn't really decide how worn the existing chain might be. Based on the fact that the motor doesn't look to have been apart I expected it to be the original JWIS (IWIS) factory rivetted item.
Having ordered a replacement IWIS chain and comparing new and old I was surprised to find that the newer chain had more side deflection than the old (see pic, new chain below old). I know this is very unscientific but it often gives an indication as to how knackered a simplex chain is based on link wear.
I then compared the chains lengths under load (20 KG) and was interested to find that the old chain was elongated by about 1.5 mm in comparison to the new. Interesting then that the older chain exhibits less side deflection but under load more elongation !! Not what I would have expected.
So, what's the point of all this? I'm not sure really other than to say that the original IWIS seems to have faired well over its 90 hours of use, and that simple assumptions can be misleading.
cheers
Dino