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Honda voltage rectifier - HOT!!
itiejim - 29/1/08 at 05:15 PM

I have just replaced the rectifier on my Blackbird engined Fury as the old one had died (fairly common I'm told).

Anyway, the new one is now on, and works - but I'm really surprised at how hot it gets (and how quickly). Hot enough not to want to hang on to it after five minues or so. Is this normal?

I don't really want to have to replace it again...


Jon Ison - 29/1/08 at 05:24 PM

yup, they get very very hot, I have moved mine onto a lower chassis rail rather than behind the head on the bulkhead where it had a head start at been a tad warm.

Have you got it sat on a good heat sink ? they need to be.


BenB - 29/1/08 at 05:34 PM

They do get hot!!! Mount it on something metal (preferably an aliminium sheet with good airing) and if possible use some CPU thermal grease to aid heat transfer.


Bob C - 29/1/08 at 05:36 PM

just a word about heatsinking - screw it onto aluminium if you can, steel is a lousy conductor of heat, three times as bad as ally. Just don't imagine that the car chassis tubes make an effective heatsink.


itiejim - 29/1/08 at 05:41 PM

It's currently screwed onto the alloy forming the end of the passenger footwell - rather near the back of the head though.

I've got some grease designed for lubricating the Exup valves in Yamaha bike exhausts - so it's well up to extreme teperatures - do you suppose that will help the heat transfer?

Many thanks for the replies.


Jon Ison - 29/1/08 at 05:53 PM

I have had no trouble since I put mine here............. Rescued attachment reg.JPG
Rescued attachment reg.JPG


Crazy Eddie - 29/1/08 at 06:06 PM

quote:
Originally posted by Jon Ison
I have had no trouble since I put mine here.............


Well to be fair Jon that one is an upgraded Rectifier as well isn't it?
I went through 2 standard reg rec in about as many months so bought one like Jon has from pattenparts.net and noticed that it still got warm but not hot.
Then I even added a PC fan and now it doesn't even get warm so really impressed. Fan only cost £6 from ebay and I just have it wired to ignition so Happy Days


You can just see it top left of picture


BenB - 29/1/08 at 09:47 PM

I think you have to be careful with grease. Some are heat conductive, some aren't....


onzarob - 29/1/08 at 10:13 PM

You want heatsink compound, grease is a lubricant. the compound is a paste that makes sure the maximum area is in contact with the heatsink


David Jenkins - 29/1/08 at 10:25 PM

Maplins will sell you a small tube of heatsink compound for not too much cash...

[Edited on 29/1/08 by David Jenkins]


macdave69 - 30/1/08 at 12:56 AM

I went through a stack of these until pointed onto the right track!
Mine is bolted onto the front of the steering rack mount on a 150 x100 x8mm ally plate and covered in Maplins heat transfer compound. 1500 miles later no problems. it still gets warm but doesn't blow anymore


David Jenkins - 30/1/08 at 08:50 AM

If you want to be really swish, you could buy a finned heatsink while you're in Maplins - bolt the unit to the flat side, make sure the fins are in a breeze and you're well away!

(said only a little bit tongue-in-cheek).


rf900rush - 30/1/08 at 08:23 PM

Just Had a CBR400RR (NC29) one blow.
Same type is fiited to many bigger bikes.
As I need the bike for work I fitted a Suzuki GSXR600 regulator which was left over for my megasquirt parts.
Had a quick look at both honda and Suzuki diagrams, then wired it in.
All Ok so far.

Bad point... it's 3 times as big so had to relocate it.
Good point... as above.... has it's own heatsink.
it looks much more heavy duty than the honda part.
time will tell.

Plus if it goes bang the bike is not to expensive now to replace.