Rubbing fan

[Matt_B]

Just rebuilt the top end with 2 new heads and installed a twin port fan instead of the single port one. Ran sweet on the bench but now the fanbelt is on and tightened up the fan is rubbing inside the housing, only at a very small point but makes a racket when running

Any advice on curing it? Preferably without taking the engine out PLEASE!

 

[Anonymous]

Just rebuilt the top end with 2 new heads and installed a twin port fan instead of the single port one. Ran sweet on the bench but now the fanbelt is on and tightened up the fan is rubbing inside the housing, only at a very small point but makes a racket when running

Any advice on curing it? Preferably without taking the engine out PLEASE!

you can take the fan out without removing the engine undo strap around alt or dyno undo 2 ten mill bolts or 3 cant remember and wiggle it out some times you have to remove the carb then look for the marks on the fan or just loosen the strap around alt and loosen the ten mill bolts and move the whole fan then tighten a check for catchung good lick 8)

 

[Toad]

You may be able to (take off the fan belt again) slacken off the Dynamo/alternator strap and the 4 10mm bolts (on the fan mounting bit of tinware). Make sure that the fan sits happily and tighten the strap and the 10mm bolts back up. Make sure that the strap is nice and tight...and that the fan belt is not too tight!
(Note: it may be tricky to get to some of the four 10mm bolts depending on what carb/s you have...but it can be done with a fiddle!)

Good luck

 

[BenSSP]

Just rebuilt the top end with 2 new heads and installed a twin port fan instead of the single port one. Ran sweet on the bench but now the fanbelt is on and tightened up the fan is rubbing inside the housing, only at a very small point but makes a racket when running

Any advice on curing it? Preferably without taking the engine out PLEASE!

When you say ran sweet on the bench was that turning over by hand in the housing? & it's definitely a twin port shroud?

I would take the belt off, spin it over, if the rubbing stops unbolt the ends of the shroud, tighten the bejesus out of the clamp, retighten the ends & make sure the belts not too tight, remember to put the unused shims behind the washer on the top pulley, you should have 10 in total

 

[Matt_B]

Cheers guys, will have a fiddle! There's always something !

 

[Matt_B]

BenSSP, how do you know if it's a twin port shroud? All I know is that it's a 36hp version bought from you guys about 4yrs ago.

 

[sparkywig]

Single port fans are much narrower than twin port ones.
If you've fitted a twin port fan in a single port (non-doghouse) fanhousing it will foul.



Single port fan (approx. 26mm) on the left, wider (approx. 37mm) twin port fan on right.

 

[Anonymous]

:lol:

 

[Matt_B]

why :| :|

Why what?

 

[Matt_B]

It only catches on a very small part, less than 1/8th of a turn of the crank - investigation required :|

 

[BenSSP]

BenSSP, how do you know if it's a twin port shroud? All I know is that it's a 36hp version bought from you guys about 4yrs ago.

That takes a twin port fan, so does the single port one

 

[Matt_B]

Thanks for the advice, loosened off the fan housing bolts on the side and took off the fan belt, then tightened the alternator strap as much as I could. Put the belt on, tightened the bolts and hey presto no rubbing of the fan

Brighton breeze here I come

 

[Anonymous]

us old uns know something or 2 we arnt all senile :lol: