288 carb mount

[paragonbuilder]

I'm working on my FIL's 288, and noticed something I dealt with on my 181 as well.

It seems that the entire carb and intake tract needs to drop to line up properly. This picture is with a gasket delete, but even with the gasket it seemed like it should drop. When porting and cutting the base, this must be worse.

How do you deal with this?

I considered tapering the intake block slightly, but then the screws won't be lined up correctly. Only other solution I see is to trim the "support" for the Intake block, and clearance the carb floor for it to drop.

Thoughts?

 

[mdavlee]

Trim the floor.

 

[paragonbuilder]

@mdavlee
@Mastermind
@srcarr52
@Termitebuffet

 

[paragonbuilder]

Trim the floor.

Beat me to it Mike. Thanks!

 

[mdavlee]

No problem.

 

[awol]

I have this problem on all of the 281/288 saws; if you drop the jug far enough, the carb will even bottom on the fuel tank. My cure is just to mill the intake surface at a slight angle. A large flat file works well. The screws still work ok if you don't go to far.

 

[Mastermind]

I like that idea Alan.

 

[paragonbuilder]

I have this problem on all of the 281/288 saws; if you drop the jug far enough, the carb will even bottom on the fuel tank. My cure is just to mill the intake surface at a slight angle. A large flat file works well. The screws still work ok if you don't go to far.

So to be clear, taper the intake surface on the jug? Not the intake block?

 

[Mastermind]

So to be clear, taper the intake surface on the jug? Not the intake block?

Yes. The block has raised sealing lines on it, so tapering the flange on the jug is the way to go.

 

[awol]

Yes, I do the surface of the cylinder; the farther away from the pinch point you change the angle, the less changing you will have to do.

 

[paragonbuilder]

Yes. The block has raised sealing lines on it, so tapering the flange on the jug is the way to go.

Ahha! I see that now. Thanks guys!

 

[srcarr52]

Trim the sealing lip for the boot around the intake block with a die grinder. If you dropped the jug a lot you'll need to trip the rubber seal too.

 

[paragonbuilder]

Trim the sealing lip for the boot around the intake block with a die grinder. If you dropped the jug a lot you'll need to trip the rubber seal too.

Thanks Shawn. I did find I needed to do that. I took about .040 off the top of the intake flange to eliminate the pressure on the intake track. Then I trimmed the rubber seal. Everything looks tight and true now. Sealant is curing, I'll find out tomorrow if she's sealed up good...

Hooray 288!

 

[paragonbuilder]

Well I fired her up this morning and she tuned perfect. Cut with her a bit this afternoon and something felt off. Brake cleaner found a leak where the carb meets the intake block. So either it still has to drop, or the gasket I reused failed. I'll know tomorrow...

 

[paragonbuilder]

Here she is after tuning this morning