Necessary to replace alternator gasket?

Jimmy Bottlehead

Hi all.

Changed the stator/alternator cover on my CB400 yesterday. Sealing it up with the bolts alone is letting oil leak out so it looks like I've to replace the gasket for it.

I'm still fairly new to any type of DIY work but it looks like ordering one from the UK is my only option - if there's anything I've not thought of though, would appreciate the advice.

Pat Dunne

Just make sure that you tighen the bolts evenly. Remember over tightening may cause you to warp the joint between the two surfaces. Don't screw in the bolts and tighten them in a clockwise or anti cloockwise pattern. Tighten them in a star pattern.

CJhaughey

Smear a bit of grease over both sides of the gasket, it will help it stay in place during assembly.
Check all the bolts are the same length and if they are not then find out which ones go in what location.
What I do when ripping a cover that I may not refit immediately is to get a piece of cardboard (cereal packet etc) and trace the cover and mark the holes manually, then make a hole in the appropriate location and fit the bolt that came from that hole.
If you are waiting on a gasket and are worried it will get dirty or disturbed, wrap it in clingfilm.
Clean the old gasket off with care you dont want to create any leaks by damaging the mating surfaces.

Richard tea

I can't think of the name of the stuff now but it was a blue liquid gasket. I've used this on the alternator cover and it done the job. No leaks.

CJhaughey

Richard tea wrote: »

I can't think of the name of the stuff now but it was a blue liquid gasket. I've used this on the alternator cover and it done the job. No leaks.

Thats silicone RTV gasket sealant you are thinking of.
Its good stuff but you just need to be careful that gobs of it don't come off inside the engine if the engine oil is inside the alternator.
The blobs can block oilways leading to bad results.
If your covers are in good nick it shouldn't be necessary to use sealant.
Gasket remover spray is great stuff to avoid tedious scraping and damage.

landmarkjohn

CJhaughey wrote: »

get a piece of cardboard (cereal packet etc) and trace the cover and mark the holes manually, then make a hole in the appropriate location

LOL, you took me back about 30 years .... but I think I was actually making a replacement gasket!

Good idea BTW, especially if you have one with a bit of an iffy thread.

Chippy01

A good motor factors should stock sheets of gasket paper. Only a couple of €s per A4 sized sheet iirc. Always handy to have a bit for little jobs like that.