Posted by: vintagebug - 16 July 2013 13:55:19
Can anyone tell me what the correct size is for a 25hp fan belt? I've seen 2 or 3 different sizes advertised as 25hp belts, so I'm not sure which is the correct one. And where would be the best place to buy one from- KK, Just Kampers, VW Heritage, AN Other? Thanks, Dave

Posted by: Piet - 16 July 2013 22:15:56
Hi Dave, don't know the size for 25 hp '53 but I can tell you this: before my pulley exploded I had 111 903 137E on it and fitted just fine with the perfect 15mm lash. Now with the same new back pulley, it doesn't fit anymore, way too much lash and I had to install 111 903 137B. Just saying that you may have to try some for a perfect fit. They changed these pulleys quit alot in those days. Who knows what combination is on yours meaning crank and generator.

Posted by: vintagebug - 16 July 2013 22:50:55
Thanks Peter, I think I might have to do as you suggest, and try a few until I find the correct one. For example, so far I have seen 3 advertised, all saying they are for 25hp engines, but all are different sizes! 1. 111903137E, size 11.3 x 912 2. 13 x 850 3. 111903137, size 13 x 900 Anyone else like to chip in?

Posted by: Jules - 16 July 2013 23:36:04
[quote=vintagebug]Can anyone tell me what the correct size is for a 25hp fan belt? I've seen 2 or 3 different sizes advertised as 25hp belts, so I'm not sure which is the correct one. And where would be the best place to buy one from- KK, Just Kampers, VW Heritage, AN Other? Thanks, Dave[/quote] We do sell them at Karmann Konnection, not sure off the top of my head if we have them in stock, but I think we most likely do. You are welcome to give me a call to discuss and get one ordered!!!

Posted by: vintagebug - 16 July 2013 23:55:14
Thanks Jules, I may well give you a call tomorrow! I've been doing a bit of digging around on t'internet & it seems that 13 x 850Li (inner length) is probably the best one to go for. For any other nerdy types like me this equates to code A33.5! :wink: Optibelt seem to do A33 (a bit too short) and A34 (a bit too long), but they don't do A33.5. Continental appear to do the A33.5. I really must get out more often... :shock: Dave

Posted by: Sunroof53 - 17 July 2013 07:02:48
I had the same trouble when I changed my crank pulley for a 25hp one ,and like the above I have fitted an a33.5 continental belt.

Posted by: vintagebug - 17 July 2013 09:23:36
[quote=Sunroof53]I had the same trouble when I changed my crank pulley for a 25hp one ,and like the above I have fitted an a33.5 continental belt.[/quote] I saw your post on a thread on The Samba :wink: I guess the A33.5 fits ok?

Posted by: Jules - 17 July 2013 13:45:58
[quote=vintagebug]Thanks Jules, I may well give you a call tomorrow! I've been doing a bit of digging around on t'internet & it seems that 13 x 850Li (inner length) is probably the best one to go for. For any other nerdy types like me this equates to code A33.5! :wink: Optibelt seem to do A33 (a bit too short) and A34 (a bit too long), but they don't do A33.5. Continental appear to do the A33.5. I really must get out more often... :shock: Dave[/quote] I just checked what I have in stock, there is one left and it's marked 13x850 La, and they are made in Germany.

Posted by: vintagebug - 17 July 2013 14:05:34
[quote=Jules]I just checked what I have in stock, there is one left and it's marked 13x850 La, and they are made in Germany.[/quote] Thanks very much for checking, Jules. However, I think I need 13 x 850 Li (inside length), so the one you have in stock would appear to be too short for me (La refers to the outer length).

Posted by: Sunroof53 - 17 July 2013 17:26:24
[quote=vintagebug]I saw your post on a thread on The Samba :wink: I guess the A33.5 fits ok? [/quote] Yes I ran it with no problems .They are only a few pounds from a retailer .Bearing suppliers tend to sell that kind of stuff. Mike