Base gasket leak

[Craig54]

How hard is it to do the base gasket and what should I look out for.

[hikermikem]

Not hard, but usually it leads to replacing the head gasket to insure no leaks there. There's also 4 o-rings that go around each piston bore as well.

Most also install new rings, & valve stem seals while you're in there.

Scraping off the old gasket material is the worst part - be careful not to gouge the aluminum. I've had luck using a chemical gasket remover to first soften the stuff making it easier to scrape. It's a very time consuming process, especially if it's the original gasket.

Recommend using OEM gaskets as well, but aftermarket valve stem seals from Z1 work well & are much cheaper.

[mike_of_bbg]

I'm going through this right now (well I've set off to replace the head gasket but of course disturbed the base gasket). Clean your engine well before you disassemble; particularly the area behind the cylinders where it meets the engine case. There's bound to be a lot of grit stuck back there, and you don't want it falling in to your motor.

[Runningdog]

I'm exactly at that point in the winter work schedule......I aim to try the 3M Roloc bristle pad route, along with Permatex gasket remover for those areas that I cannot reach with the pad.

The old o-rings are really welded into the grooves around the barrels, so there'll be a bit of sitting at the bench, music in the back-ground, picking at them with a dental tool.

Then a bit more cleanup, attempt some silver VHT paint on the jugs, head and cam cover, and back together. Head has new valve seals, bronze guides in the exhaust valves, some porting on the intakes (just to take the rough patches off), and cross-hatching done on the cylinders. Should run like a new bike.

This exercise was precipitated through some minor base gasket seepage, so may as well do all while the upper parts are off.

[Craig54]

Tossing up wether to have a go or throw the tarp over her, cash in the plates and think about it another day when I am more inspired.
I would hate to stuff it up and I cant afford to have it done.
How long does it take to strip down and rebuild ....head was done less than 10k ago new valves etc cost heaps at the local shop. So I guess I would only have to repace the rings.

[mike_of_bbg]

If you only have 10k on the rings that are in there I see no need to replace them. If you can test the engine compression first. Just replace the three gaskets (base, head, valve cover). It took me two hours working alone to get down to my base gasket. Of course then there's the time spent cleaning, and assembly is slower going.

Have you ever done this kind of a job before? Do you have a proper torque wrench?

Basically the process goes like this:

1) Remove seat/tank, disconnect battery
2) Pull carb rack
3) Lock cam chain tensioner
4) Disconnect tach cable
5) Remove valve cover and plugs
6) Remove ignition cover, turn to TDC - Take picture or make notes of cam positions
7) Remove cam caps - wrap a wire around cam chain so you can fish it out before dropping it
8) Remove cam shafts
9) Unbolt exhaust and remove from head
10) Unbolt head
11) Pull head and cylinder

Clean everything up and slap it back together with fresh gaskets. The exhaust rings can usually be re-used with no issues. You can use hose clamps as ring compressors, and there's a special set of blocks you can make to hold a pair of pistons steady when dropping the cylinders back on. It helps to have two people to get the cylinders back on, as the alignment must be just right.

[Nessism]

I'm exactly at that point in the winter work schedule......I aim to try the 3M Roloc bristle pad route, along with Permatex gasket remover for those areas that I cannot reach with the pad.

Go easy with those abrasive pads. Machinist guy that did some work for me said those things ruin a LOT of parts, or maybe I should say misuse of them does. The gasket remover spray will soften the gasket, but it will take several applications. Paint stripper is basically the same stuff so you might want to use that if you have some laying around.

[Craig54]

Tried something like this on a 350 twin back in 1973 and had parts left over... wasnt the best outcome,
spoke with a couple of local shops and the are looking at 6-8 hrs to do the job which is roughly $5-800 all going well + parts so I would be looking at $1000 to do the job.
One guy said use extra fine wizzer pads to get the gaskets off and sugested if I have a go to take the motor out as it makes fitting the barrels much easier. mmmmmmmmm

[Nessism]

It's more work to pull the engine than just replace the top end with the engine bolted in place. Please listen to us, we won't steer you wrong.

One other thing is to always use OE gaskets. Cheap aftermarket gaskets are very iffy, particularly Athena brand base gaskets. Don't ask me how I learned this.

[Suzuki_Don]

Two things. First it is a 1000 you are working on and these motors are easier to get the barells on than the smaller models like the 550 & 650 which have the cylinder studs much closer together. So don't bother removing the engine from the frame, follow ness's advice on this one. Plenty of people to walk you through how to do this job.

Second I made my own base gasket and it works fine, so don't think you have to rely on the recognisable gasket manufacturers. I can't work out how their gaskets fail and a home made gasket works fine.

[mike_of_bbg]

My Athena base gasket held fine, but the head gasket was weeping oil. I think it's more a matter of the design (little orange rings letting go?) and the installer, but yeah I went with Suzuki OEM gaskets for this replacement (still waiting on the base gasket). If you're ordering stuff anyway, base gaskets are cheap. Think you'll find that, while definitely do-able, this is a job you won't care to repeat any time soon.

[Nessism]

My Athena base gasket held fine, but the head gasket was weeping oil. I think it's more a matter of the design (little orange rings letting go?) and the installer, but yeah I went with Suzuki OEM gaskets for this replacement (still waiting on the base gasket). If you're ordering stuff anyway, base gaskets are cheap. Think you'll find that, while definitely do-able, this is a job you won't care to repeat any time soon.

Those green Athena base gaskets can't take the normal clamp load imposed by the head - the gasket crushes down and extrudes out of position, which releases clamp load on the head. If your head gasket leaked it was most likely because of torque falloff on the stud nuts because of the base gasket.

The Athena MLS head gasket in the kit I used was actually pretty good, but the base gasket is a non-starter.

[mike_of_bbg]

Sounds plausible. It did seem like there was a surprising amount of gasket visible around the base - but that was also true from day 1. When it goes back together this time it will be with genuine Suzuki gaskets for both the base and the head. The Suzuki head gasket I have is still fiber, but with the integrated seals in the corners. Will probably also 3bond the cam chain tunnel o-ring into place.

What do you recommend for a re-torque interval? I've seen 5 heat/cool cycles and 100 miles as suggestions.

Those green Athena base gaskets can't take the normal clamp load imposed by the head - the gasket crushes down and extrudes out of position, which releases clamp load on the head. If your head gasket leaked it was most likely because of torque falloff on the stud nuts because of the base gasket.

The Athena MLS head gasket in the kit I used was actually pretty good, but the base gasket is a non-starter.

[Nessism]

What do you recommend for a re-torque interval? I've seen 5 heat/cool cycles and 100 miles as suggestions.

Suzuki calls for the first service at 600 miles so checking at 100 miles should be above and beyond (assuming OE gaskets are used). On my first engine build I checked after two heat cycles, and again soon after because the torque fall-off was extreme with the Athena base gasket. Every time I checked the torque was low so I kept checking and tightening...which is when I noticed the base gasket starting to extrude out of place. At that point I preemptively replaced both the base gasket and head gaskets with OE parts, and the torque falloff was only slight after that.