Blown 661...again
- Thread starter angelo c
- Start date
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Thanks kev...
Some people poo-poo silicones, yet some have far superior gasoline ratings than the so called fuel resistant chemical curing sealers like 1104..
Which ones are rated for use with gasoline?
One that stands out is Threebond 1207c which is Hondabond HT.
It changes by only 0.3% after submersion in petrol for 24 hours.
The so called petrol resistant 1104 changes by -3.9%.
Don’t get me wrong, some silicones are horrific. Threebond 1211 which lots of people use for sealing cases in 2 strokes, changes by nearly 20%
I’ve only used yamabond 4 and motoseal. I believe both are mostly impervious to gas and oil. I’ve worked on a handful of 029-039 and all were sealed with Dirko. Haven’t seen where it ever failed, but I’m aware of the precautions against using silicone near gas.
I don’t use it personally because it’s thicker than what I like and it’s a bear to clean off and prep once it hardens.
Not really certain if the hype about not using it is overblown or not. I’d think they’d use a different product if it didn’t work
Yeah I like Yamabond 4 too (threebond 1215), it changes by 4.7% which isn’t too far off the so called petrol resistant sealers, it’s much cleaner to use and holds up well. It smells nice (minty / oxime) and won’t seal up in the tube like the acetic silicones like Dirko.
The thing I hate about threebond products is their tubes that always get holes in and their caps ALWAYS split and never seal properly.
That said, I have yet to find a sealer that comes close to Dirko all round. It’s got the highest temp rating, highest strength rating, highest shear strength, excellent petrol resistance, it applies tenaciously ect. It cures a bit quick for me and seals in the tube, but there are work arounds..
I suppose the real question is, does any of that matter? Probably not. If a sealant only needs to withstand 150c engine temp and a sealant can withstand 200c, why do you need something like Dirko that has 315c temp rating?
Edit:
Motoseal isn’t as good of a petrol resistance as threebond or Dirko and isn’t a gap filler (don’t use motoseal on clamshells), but I like the chemical smell and is easy to apply. Sets up fast though.
The thing I hate about threebond products is their tubes that always get holes in and their caps ALWAYS split and never seal properly.
That said, I have yet to find a sealer that comes close to Dirko all round. It’s got the highest temp rating, highest strength rating, highest shear strength, excellent petrol resistance, it applies tenaciously ect. It cures a bit quick for me and seals in the tube, but there are work arounds..
I suppose the real question is, does any of that matter? Probably not. If a sealant only needs to withstand 150c engine temp and a sealant can withstand 200c, why do you need something like Dirko that has 315c temp rating?
Edit:
Motoseal isn’t as good of a petrol resistance as threebond or Dirko and isn’t a gap filler (don’t use motoseal on clamshells), but I like the chemical smell and is easy to apply. Sets up fast though.
Thanks for that info.
Well here is a question. Being a dumbass I put a layer of Dirko on the crankcase edge of a Stihl 028 only to find out that I have the wrong crankcase gasket. I was thinking since it doesn't really get hard I would just leave it on and let it squeeze together when I find a gasket. Only thick enough to make the gasket stay in place.
Or, I can take a die grinder and a brass brush and have it off in about 30 seconds.
Or, I can take a die grinder and a brass brush and have it off in about 30 seconds.
Make sure.you vacuum test it first....
i am always leery when a saw comes in with sealer used where it is not required,
question to op,,
why did you put sealer on base of cylinder? did u use new base gasket?
and what is part number on module? is it possible that it has old module on it with new solenoid?
saying it is late 2020 model is not a guarantee imo
sorry if seem dumb questions,
question to op,,
why did you put sealer on base of cylinder? did u use new base gasket?
and what is part number on module? is it possible that it has old module on it with new solenoid?
saying it is late 2020 model is not a guarantee imo
sorry if seem dumb questions,
I thought I rebuilt this saw previously but it's either another saw or the previous owner has his story wrong. I don't own any red gasket stuff.
I'll run the serial number later when I stop by the dealership.
Can't imagine what it would hurt. And, if it makes your gasket keep from wandering around. I use spray contact cement on auto exhaust manifolds all the time. Same difference.
Certainly wouldn't cause it to score a few top ends...
With 11ty +- psi bishMake sure.you vacuum test it first....
Unless sealer was trying cover a leak
had a ts420 ran like crap- sealer on cylinder base trying to cover a damaged block that would not seal with gasket-so yes it can depending on reason
so you or I may know the reason why you or I used sealer- but if someone else did it then why? As you said you didn’t use sealer?
and it doesn’t matter on exhaust side what you use- don’t even really need a gasket as evident on some engines.
I have used Honda and yamabond on BGD. But those are not red. And this one clearly has an oem bg
When a saw is a habitual problem like this, it is time to look at other factors. I would not send this out without a new carburetor. Unless the fuel is that bad. It is lean. That has to be addressed.
