Jump to content

350LC Losing coolant


mcferreira100
This post is 3550 days old and we'd rather you create a new post instead of adding to this one. You can't reply in this post.

Recommended Posts

I`m wondering why is there any paint under there at all?

Link to comment
Share on other sites

Do you want an ad-free experience? Join today and help support the Yamaha Owners Club.

Did they paint it "to look nice"? do you think. Might be the reason you had a leak, just guessing here but I would clean all that crap off before I rebuilt it. Does the old gasket have a sort of sealant or black paint finish?

Link to comment
Share on other sites

Seems to have a black paint finish. Can I clean the head with Acetone?

Link to comment
Share on other sites

Don't see why not it's not going to effect the metal and it might get the crud off, I would try paint thinners first tho.

Link to comment
Share on other sites

After cleaned " inspect it for a hairline crack,,, this would open when hot, and compression escape into the waterways,

I had a van that when turned over with starter the compression bubbled out the expansion bottle [ cap off bottle ] :eusa_doh:

Link to comment
Share on other sites

Ok I see now the head gasket in 3 parts..there was still part of the gasket attached to the head.

My mechanic friend came to have a look today and noticed one of the head bolts pretty rusted indicating water getting to it. He says this indicates a possible crack in the head in that area? so he reckons I might need to replace the head..not happy. Is there any other options?

2015-02-18%2012.39.44_zps7pjeneda.jpg

Link to comment
Share on other sites

I suppose you could get it welded but would always be on your mind and it might cost more than a 2nd hand one. To be honest mate I would get another one rather than faff around with one you know is cracked. Just my opinion you understand. :shrug:

Link to comment
Share on other sites

See one on Ebay for 49 Euro from Germany..not bad..amazed to see any there at all.

But after speaking to guy who did my engine he reckons he`s seen lot of rusted head bolts as those bikes tend to stand long time and water seeps past the gasket. He assures me the head is fine.

Link to comment
Share on other sites

In that case you could get it pressure tested, don't ask me how? and see if it does in fact have a crack in it, seems to be your best option mate plus it would save you some money and put your mind at ease as to it being in tip top condition.

Link to comment
Share on other sites

Ah screw it Slice..gonna put it back together using the high temp gasket maker as the guy insisted I should do (for older bikes) and if it gives me any more crap its going in the want ads. Will rather get an air cooled four stroker anyway..don`t like having to rev the nuts off these old bikes.

Link to comment
Share on other sites

That's a plan mate, just a bit of a bugger when you have done all that work on it !

Link to comment
Share on other sites

Slice..this the gasket maker I`m told to use..pretty expensive stuff

2015-02-18%2014.12.04_zpstrqxv6zz.jpg

Head looking lot different after I realized stil a gasket on there and sum paraffin cleaning

2015-02-18%2015.31.27_zpssxv5czrj.jpg

Will give plugs bit of a wire brush clean too.

Link to comment
Share on other sites

Don't like the idea of putting sealant on a cylinder head the gasket should do the job on it's own without the extra stuff. if you used it JUST where the water ways pass through then that might work but as I said not to keen on slapping it on all over! Still you have talked to your mate and he says it's fine so go with someone who knows what he's on about. Good luck Mc hope it works out ok.

Link to comment
Share on other sites

  • Moderator

wasn't there some type of blue dye which detects cracks in alloy?

maybe this

http://weldingsupplies.dynaflux.com/category/-i-crack-check-i-non-destructive-testing

Link to comment
Share on other sites

Nuclear grade cleaner !!! Hells teeth Drewpy.

Link to comment
Share on other sites

Hmm , I've never used that stuff on an LC head . If you do use it , will you use the gasket as well ? When using that stuff don't squeeze it on like toothpaste as I've seen people do when using it on clutch/magneto/waterpump covers , on a 4stroke it blocks the oilways very quickly and depending on which colour used can make your engine oil look very pretty as the lumps get chewed in the gears . Better to put a tiny bit on your finger and lightly coat the mating surface . If you spit on your finger first it works better ( ahem ) . A thin film's all you need . I'd rub the mating surface of the head on a piece of plate glass with some fine emery paper taped to it and try a new gasket first though . With your bike stripped already it's a 5 minute job . Nothing wrong with those bolts that a squirt of oil wont sort out .

Link to comment
Share on other sites

There is additives nowadays that seals poreus heads , works well too , if the gasket dosnt work ,, :yeah:

Link to comment
Share on other sites

Head back on today..torqued to 22ft pd. Started and let idle itself hot then let it cool after which re-torqued to 25. Also tried slightly thicker washers on the head bolts in case things are bottoming out. Carbs also set leaner (2nd notch from top). Took it for a spin and so far all is well..fluid in reservoir not rising. Will go for longer ride tomorrow..weather permitting.

Link to comment
Share on other sites

×
×
  • Create New...