82 GS400 8 valve, poor running/excessive blow by

[Epic_username]

Good call guys, both sides cracked from spark plugs hole to exhaust valves.

So now what, I know of another 8 valve 400 parts bike, $150 but unknown condition. Anyone in BC have a 450 top end?

[GregT]

Good call guys, both sides cracked from spark plugs hole to exhaust valves.

So now what, I know of another 8 valve 400 parts bike, $150 but unknown condition. Anyone in BC have a 450 top end?

Before you go too deep into the top end swap, see what the condition of the lower end on yours is. Blowby can do nasty things to oil.

[Epic_username]

Well, when it was running it was quiet, I can't feel any play in the rods, and odometer says about 30,000 kms, so I'm willing to chance the bottom end.

Looking at part numbers and the base and head gaskets are the same between the 8 valve 400 and the 450. It's hard to say without having both of the heads and jugs beside me, but it might be possible to bore my jug for the 450 pistons and use the 450 head, for some money savings.

I know I sound cheap, but it's a free motorcycle and I'm not sure how much I wanna put into it...

[Gorminrider]

The GSX 400s are a lot more common than 450s in Canada. I think Canada only got 450s for 1 year, then Everywhere got the 500 twin for a long long run of years...(it's the successor to the 450)

I'd stick to the gsx400 myself- it's not a BAD engine. Mine hum along great.

[John Park]

Good call guys, both sides cracked from spark plugs hole to exhaust valves.

So now what, I know of another 8 valve 400 parts bike, $150 but unknown condition. Anyone in BC have a 450 top end?

Abbotsford is only a bicycle ride from the US. I got a 450 topend from Oregon a few years ago for cheap. Prices can be highly variable; I got jugs and pistons for $40 but paid $120 for a complete head, and with exchange it was still about $200 CDN. GSX head gaskets are scarce, as Suzuki Canada didn't seem to have any last I checked. 450 gaskets are still around.

I suspect that all the 8 valves will by now have at least the beginnings of plug hole cracks; the question is whether they will become serious enough to matter. 450 heads run a lot cooler and seem unfussy about fuel. More midrange torque and about the same power at 9,000. Because they are rugged, used parts in useable condition are still out there on Fleabay, last I looked.

What is your bike like? Condition, model, etc. Did you search it out or did it fall into your lap?

[Epic_username]

The head gasket is the same as the 450, at least the part numbers have superseded into the same part number for both the 400 and 450.

The bike isn't in amazing condition, but it's all there and I've had it a few years now. It really fell into my lap but I've grown attached, and would like to save it if at all possible. So far I've only bought intake boots ($40 new) a nicer front fender and the plastic thing between the gauges with the warning lights again for a total of about $30.

Here's some pictures, they aren't recent. I was on this board a couple years ago, maybe it will be remembered. Someone sent me some side covers, a brake plate and a lever but now for the life of me I can't remember who...IMG_20180810_190708-271--1.jpg

[Epic_username]

I've got a line on a 450 engine, it's 4 hours away, but complete for $250 isn't bad. Just trying to find the time to head up there...

[John Park]

The head gasket is the same as the 450, at least the part numbers have superseded into the same part number for both the 400 and 450.

The bike isn't in amazing condition, but it's all there and I've had it a few years now. It really fell into my lap but I've grown attached, and would like to save it if at all possible. So far I've only bought intake boots ($40 new) a nicer front fender and the plastic thing between the gauges with the warning lights again for a total of about $30.

Here's some pictures, they aren't recent. I was on this board a couple years ago, maybe it will be remembered. Someone sent me some side covers, a brake plate and a lever but now for the life of me I can't remember who...[ATTACH=CONFIG]58580[/ATTACH]

The head gaskets for the two valve 400 [77-79], the 8 valve, and the 450 are all different and do not interchange, BUT, you could perhaps make a 450 gasket fit a GSX although the fire ring design is not even similar.

The side covers, etc., came from me.

[John Park]

I've got a line on a 450 engine, it's 4 hours away, but complete for $250 isn't bad. Just trying to find the time to head up there...

Where's 'up there'? PM me if it's anywhere around here. And complete for $250 is quite reasonable. The GSX carbs you have are quite different and IMO way better than the EPA ones on the 450s. The jetting's good but the needles will need to go up one notch. The intake boots are different, unfortunately, but I think I still have some old but not yet dead ones. Otherwise, it's plug and play and the airbox lines right up.

[Epic_username]

I thought so!
It's in Comox, so there's ferry fees too but still worth it (makes a nice day trip). Heading up that way tomorrow.

[Gorminrider]

Too late, maybe but if you read this while you're in Comox, there's a 450 in Jack's parts place on Ryan Road east end toward the Air Base... back in the yard...if you need carbs or just the jets and such , or even engine bits, they might still be there.

[Epic_username]

I called Jack's yesterday, that's where I'm headed. He said he still had the engine

[Gorminrider]

haha! I was just going to PM you in case your email might notify you on the road......it's been sitting out in the yard awhile but that shouldn't matter too much.

[Epic_username]

Well I'd say my trip Jack's was a success. Now to enjoy the rest of my day on the island

[Epic_username]

So I've got the engine bolted in, trying to fit my tach cable and it just won't go it.are the tach cables different between the 400 and the 450?