Reading about radiator hose failures on some of the other models makes me wonder about those on the 630. There does not appear to be a source for silicone hoses for the 630 unless those in the Special Parts Catalog are applicable. The catalog isn't too specific other than black cap or silver cap. Are upgraded hoses and fittings available, and do they seem to be needed? 'Don't see any threads on 630 hose failures.
resurrecting an old thread because I just blew a hose today on my 630. Now I'm wondering the same as the OP. It does seem to be that the hose coming out of the water pump is rubbing against the back of the radiator fins. I can imagine that vibration would wear a weak spot in the hose and cause it to bust. If no better solution is available I'm going to put some steel braiding over the hose where it runs near the radiator fins to cut down on the rubbing. ETA: Ken, I did find some GPLUS silicone hoses on ebay but the reviews I saw weren't great - said they weep a lot and you have to keep adding coolant. I guess I'm going to go back to standard rubber hoses ... now to try to find one.
Talking with a mechanic and he talked about silicon being great for race vehicles but no so much for street vehicles.. Reason being they seep so on a race vehicle that gets checked and changed every race, no problem. On a street vehicle there is more of a tendency to fill and forget it, thats where the problem can start! Just what I heard...I have yet to form an opinion
I personally have a hard time believing and have never seen hoses sweating coolant....where I was going with this is that do you really believe any of the listed top tier racing teams from NASCAR to World superbike would use hoses that have the properties to actually leak? answer is no, zero really. Those folks do everything to prevent the slightest amount of coolant escaping. Think about it. A local "mechanic" and his thoughts, in comparison to top tier racing teams crews/engineers/crew chiefs/team owners etc. for example here are 2 of the top tier sources for silicone hoses. http://www.samcosport.com/usa/ http://www.cvproducts.com/Powersports/Categories/ PS use quality not Chinese EBay knock offs, those may leak you never know maybe that's where that opinion was formed.
From KTM Factory......also David Knight uses SAMCO exclusively (2 of many related in the moto biz), US side JGR Yamaha use CV4 silicone hoses among many others.. KTM Factory Racing Choose SamcoSport KTM Factory Team choose Samco Sport as a Development Partner for Radiator Hoses / Water Hoses because they´re a fast and reliable company who reacts quickly on our team’s demands. The Products are first class Quality with a very good fitment and a perfect finish and Performance. It is a pleasure to Deal with the People at Samco Sport, because they´re all professionals.
I don't know whether they leak, but, AFAIK, their main feature is that they don't expand as much as usual rubber hoses. The result is that, since their volume is less increased when the coolant is hot, the pressure inside them becomes higher than the one that would be in rubber hoses. So, unless you replace your radiator cap with another one which opens at a higher pressure, more coolant will end up in the radiator canister. If you install the high pressure cap, the higher pressure allowed by the silicone hoses will remain and so the coolant will boil at a higher temperature. You know, when you cook pasta on the mountains, since there is a lower air pressure, the water will boil earlier than 100°C; vice versa, my dentist sterilizes his tools putting them in a sealed pot filled with water, which reaches a high pressure and so it can boil at more than 100°C (he says 130°C) and kill more germs. When water starts boiling, its temperature doesn't increase; if its boling point is increased, it can reach higher temperatures in its liquid state. That's why, still AFAIK, those hoses are used in racing engines. I read somewhere that F1 cars have pressurized cooling systems (EDIT: actually, our engines are pressurized, too, but not so much). The problem is, IMHO, that with more pressure the risk of ruining the head gasket or other gaskets is higher.
