Motoseal on reed gasket?

Alec138
Profile picture for user Alec138
Posts
540
Joined
1/29/2018
Location
Bethania, NC US
Alec138
Bought a new reed gasket for my yz250 and was told by some others users of another forum to use a thin coat of “motoseal” on both sides of the gasket when reassembling. Local auto parts store has it but for $10 a tube its kinda pricey for only needing just a tiny bit when thenrest will sit in the tool box forever... is it actually necassary to use it or any type of “sealant” on this gasket?
|
grimsypro 10/18/2018 12:52pm
10/18/2018 12:52pm
Needs to be sealant that won't be eaten by the fuel and up to a certain temp as it's right off the cylinder. Any rtv should be good I used threebond on mine
Alec138
Profile picture for user Alec138
Posts
540
Joined
1/29/2018
Location
Bethania, NC US
Alec138 10/18/2018 1:20pm
10/18/2018 1:20pm
grimsypro wrote:
Needs to be sealant that won't be eaten by the fuel and up to a certain temp as it's right off the cylinder. Any rtv should...
Needs to be sealant that won't be eaten by the fuel and up to a certain temp as it's right off the cylinder. Any rtv should be good I used threebond on mine
Would it hurt not to use any? I really dont feel like spending $10 on a giant tube of sealant and using half a fingernails worth. Kinda tight on funds as im doing other things to my bike...
kb228
Profile picture for user kb228
Posts
6161
Joined
1/31/2018
Location
Mansfield, OH US
kb228 10/18/2018 3:47pm
10/18/2018 3:47pm
On my 2001 yz250, i didnt put anything on the gasket. Had no issues. If you want, you can put belray waterproof grease on it if youre worried about air leak or something. I really dont think a coating is required anyways. Just make sure your surfaces are clean and you tighten it correctly
1
murph783
Profile picture for user murph783
Posts
1361
Joined
3/2/2011
Location
CT US
murph783 10/18/2018 3:57pm
10/18/2018 3:57pm
You’re fine putting it on dry. I’ve used yamabond to salvage a torn gasket, but other than that there’s no need

The Shop

See All »
Falcon
Profile picture for user Falcon
Posts
10108
Joined
11/16/2011
Location
Menifee, CA US
Fantasy
798th
Falcon 10/18/2018 4:43pm
10/18/2018 4:43pm
Sealing is what gaskets do. As long as your manifold junctions are flat and straight, you don't need any sealant.
Alec138
Profile picture for user Alec138
Posts
540
Joined
1/29/2018
Location
Bethania, NC US
Alec138 10/18/2018 4:46pm
10/18/2018 4:46pm
Thanks for the opinions guys. Currently going through an air leak battle with the bike and working on fixing it so i wasnt sure if just cleaning the surface and using the gasket dry was ok...
Bearuno
Profile picture for user Bearuno
Posts
4141
Joined
6/28/2014
Location
AU
Bearuno 10/18/2018 7:51pm
10/18/2018 7:51pm
kb228 wrote:
On my 2001 yz250, i didnt put anything on the gasket. Had no issues. If you want, you can put belray waterproof grease on it if...
On my 2001 yz250, i didnt put anything on the gasket. Had no issues. If you want, you can put belray waterproof grease on it if youre worried about air leak or something. I really dont think a coating is required anyways. Just make sure your surfaces are clean and you tighten it correctly
Years ago I'd use sealant on all paper gaskets. I was paranoid about leaks.

Then when I worked at the Maico (and Acerbis , UFO, MSR and other products) distributors, working on my 320, trying different things, that required a fair amount of 'on' and 'offing' of gasket jointed parts, the owner put me onto using grease on gaskets. Not so much for a seal (which it does enhance) , but to avoid sticking and tearing of gaskets and laborious joint clean up .

I certainly don't do it with everything (nor recommend it) , but, for example, with my current experimenting with reed block / carb spacers (one of which is a pick up / exit point for 2 Vacuum lines for an automatic de-comp and a Mikuni fuel pump for my 500s 'drop' Tank) , I use sealant on the one side that will be the semi permanent side, and a light coat of grease on the 'removal' side. Works well and I've never had a problem over several decades.

It also has kept the original, big, thick HM / E Line Lighting kit gasket healthy over 15 years, and, hopefully, now the same type of gasket on the dodgy Electric start kit I use from time to time. The mongrels who made that should have used an Oring, and positive stop, male to female 'engagement' fitting of the sidecover, to the engine cases.
1
FGR01
Profile picture for user FGR01
Posts
5112
Joined
10/1/2006
Location
AZ US
Fantasy
1222nd
FGR01 10/18/2018 8:14pm
10/18/2018 8:14pm
Motoseal does work very good on the reed block but any gas-resistant sealant will do. I think Motoseal might actually be Permatex Ultra-Grey just relabled to appeal to the motorcycle crowd,
Hondas4Life3
Profile picture for user Hondas4Life3
Posts
854
Joined
7/30/2013
Location
Louisburg, KS US
Hondas4Life3 10/19/2018 7:56am
10/19/2018 7:56am
You install it dry and then leak down test it. If it leaks then you use sealant.
Alec138
Profile picture for user Alec138
Posts
540
Joined
1/29/2018
Location
Bethania, NC US
Alec138 10/19/2018 8:43am
10/19/2018 8:43am
Hondas4Life3 wrote:
You install it dry and then leak down test it. If it leaks then you use sealant.
I did a leak down test and my bike looses air due to the powervalve seal. Even using a new seal.
kb228
Profile picture for user kb228
Posts
6161
Joined
1/31/2018
Location
Mansfield, OH US
kb228 10/19/2018 8:54am
10/19/2018 8:54am
Hondas4Life3 wrote:
You install it dry and then leak down test it. If it leaks then you use sealant.
Alec138 wrote:
I did a leak down test and my bike looses air due to the powervalve seal. Even using a new seal.
Did you make sure all your surfaces are flat? If the bike ever overheated you could have warped gasket surfaces that wont seal.
grimsypro 10/21/2018 6:23am
10/21/2018 6:23am
I had a very slight leak from my power valve cover. Was barely bubbling up after 10 minutes. Smeared a bit of grease both sides of the gasket and it went away. Is yours on the inside where the rod goes through?
Alec138
Profile picture for user Alec138
Posts
540
Joined
1/29/2018
Location
Bethania, NC US
Alec138 10/21/2018 6:52am
10/21/2018 6:52am
grimsypro wrote:
I had a very slight leak from my power valve cover. Was barely bubbling up after 10 minutes. Smeared a bit of grease both sides of...
I had a very slight leak from my power valve cover. Was barely bubbling up after 10 minutes. Smeared a bit of grease both sides of the gasket and it went away. Is yours on the inside where the rod goes through?
Yeah its a very common issue on yz250s. The bore where the rod rides inside the seal gets warped or whatever and it will never seal right unless you buy a new cylinder or do this mod where you press a metal bushing into the hole. I did pull the gasket off and add a bit of grease a while back as well.
Alec138
Profile picture for user Alec138
Posts
540
Joined
1/29/2018
Location
Bethania, NC US
Alec138 10/21/2018 6:52am
10/21/2018 6:52am
Hondas4Life3 wrote:
You install it dry and then leak down test it. If it leaks then you use sealant.
Alec138 wrote:
I did a leak down test and my bike looses air due to the powervalve seal. Even using a new seal.
kb228 wrote:
Did you make sure all your surfaces are flat? If the bike ever overheated you could have warped gasket surfaces that wont seal.
Read my last reply below. I explained why it wont seal.
grimsypro 10/21/2018 11:44am
10/21/2018 11:44am
I did read up in it when mine was leaking. Sounds like a pain in the ass! Did you get it sorted?
Alec138
Profile picture for user Alec138
Posts
540
Joined
1/29/2018
Location
Bethania, NC US
Alec138 10/21/2018 12:35pm
10/21/2018 12:35pm
grimsypro wrote:
I did read up in it when mine was leaking. Sounds like a pain in the ass! Did you get it sorted?
Not going to worry about it because it causes no issues besides making a stain which simple green and a scruber will get rid of
grimsypro 10/22/2018 2:33am
10/22/2018 2:33am
Ye pretty sure it shouldn't cause a leak as the power valve is under positive pressure.

Post a reply to: Motoseal on reed gasket?