Head gasket husqvarna 245R need or not. See photos

[Jonny Vee]

just rebuilding a strimmer husqvarna 245R. Removed cylinder and found load of silicone black paste guess used as gasket

See photos after clean up

Do I need to put paste back or it will work without

Engine lost compression as ring was stuck on piston and broke

Thanks

 

[Burnerman]

I'd really go for a new base gasket here, maybe with a slight smear of blue Hylomar or similar. You don't want any sealant entering the crankcase!
John

 

[Jonny Vee]

I'd really go for a new base gasket here, maybe with a slight smear of blue Hylomar or similar. You don't want any sealant entering the crankcase!
John

John, Do they exist? I have easily found a replacement piston but base gasket.

If you know where I could find one I will order it.

Thanks

 

[Burnerman]

I'd be very surprised if there wasn't a cylinder base gasket but you never know! I'd give L&S engineers a call or maybe a horticultural dealer who could search a database for you.
John

 

[Jonny Vee]

I'd be very surprised if there wasn't a cylinder base gasket but you never know! I'd give L&S engineers a call or maybe a horticultural dealer who could search a database for you.
John

John, I`m assuming the base gasket was the plastic things that still there on the photos but obviously a bit damaged.

I can call L&S engineers but nothing shows on their diagrams.

Would the Hylomar make the job on his own?

 

[Jonny Vee]

I'd be very surprised if there wasn't a cylinder base gasket but you never know! I'd give L&S engineers a call or maybe a horticultural dealer who could search a database for you.
John

Hi John,, Speaking with L&S it seems like there is no base gasket for those machine. An instant gasket need to be used.

Is the blue Hylomar good for that or it will be another product?

Thanks

 

[Burnerman]

In this case Jonny I'd use a silicone based instant gasket, and apply it with a small artists brush. Hylomar is not really a gap filling product but it's brilliant for what it is.
Motor factors will sell you instant gasket in small tubes so it's fine for you. Builders silicone doesn't really have the ability to resist the heat involved so avoid that.
Good luck with the strimmer!
John

 

[Jonny Vee]

In this case Jonny I'd use a silicone based instant gasket, and apply it with a small artists brush. Hylomar is not really a gap filling product but it's brilliant for what it is.
Motor factors will sell you instant gasket in small tubes so it's fine for you. Builders silicone doesn't really have the ability to resist the heat involved so avoid that.
Good luck with the strimmer!
John

John

Would this one work?

Loctite High Temperature Instant Gasket 40ml

LOCTITE(r) AUTO Instant Gasket 40ml Tube Instant Gasket Replacement Any Size or Shape, Resistant To High Temperatures & Engine Fluids

www.lsengineers.co.uk

 

[Burnerman]

Yes, just the job!
John

 

[Jonny Vee]

Yes, just the job!
John

Using that sealent even if I put if very carefully and small quantities was a very bad and costly choice.

I let is dry for over 24 hour before first crank

it started at second pull and I was very happy. I let it idling for good 10 minute and then started to accelerate slightly then suddenly stopped

I opened again to find out the piston rod bearing which connected to crankshaft was destroyed.

I used a reach mix like 40:1 but not sure what caused the crankshaft to collapse that way

Strimmer is costing me more than buying a new Stihl

What could be the reason?

 

[Burnerman]

The reason for a big end bearing collapse is lubrication failure......nothing to do with the cylinder base gasket.
If this is the original Husqvarna crankshaft ( unmodified or repaired) I’ve no idea why this should happen, if the oil / fuel mix was correct.
John

 

[Jonny Vee]

The reason for a big end bearing collapse is lubrication failure......nothing to do with the cylinder base gasket.
If this is the original Husqvarna crankshaft ( unmodified or repaired) I’ve no idea why this should happen, if the oil / fuel mix was correct.
John

Same mix used on disc cutter and chainsaw. Good oil 40.1 mix

Completely destroyed the bearing and new piston also look crap on the top as been compressing metal

 

[lostinthelight]

Clamshell engines like yours that ive stripped have been sealed with silicone. Did you test the "squish" , make sure there was enough clearance between the top of piston and cylinder head before final assembly ?

 

[Jonny Vee]

Clamshell engines like yours that ive stripped have been sealed with silicone. Did you test the "squish" , make sure there was enough clearance between the top of piston and cylinder head before final assembly ?

I haven't check with any tool but looked fine. Also the original crankshaft plastic seat are still there even if in bad condition.

 

[Jonny Vee]

Anyway only way can get it back to work is a new crankshaft assembly and plastic crankshaft seat.

If anyone here have anything from a husqvarna 40 45 or 240 245 strimmer that want sell cheap let me know.

Thanks