TWO Broken Rocker Arms. GS700E.

[chef1366]

I have extra rockers if you need some.

[kirkn]

Hey, Chef, I'll probably take you up on that offer for two rocker arms. I'll need intake and exhaust for #1 cylinder (far left as you're seating on bike).

Anyone have any good sources other than dealership and Bike Bandit for parts? At this point I'll need a cam chain (endless), the three tensioner blades, two rocker arms (maybe) and a gasket kit including head and base gaskets and maybe a new valve cover O-ring/gasket.


All I did on Sunday was to clean / degrease the head and check for valve leakage by pouring acetone in the ports. #4's didn't weep at all. #1, 2, 3 began weeping acetone after 10 ~ 15 seconds and would drip about 1 drip every 5 ~ 10 seconds. I'll lap the valves, but I didn't think that leakage qualified as "bent valve" severe. I didn't do the exhaust valves yet.

I gave a quick peek into the cylinders, and they all looked good, too - no gouges or scratches. Probably just lightly hone the cylinders before reassembly.

Next will be pulling the cylinder & pistons, removing the peripherals (clutch, stator, oil liines, etc) and pulling the engine out. Then, splitting the cases.

So, the project is slowly chugging along...

Kirk

[chef1366]

If your motor hydro-locked and broke the cam chain I'd check the crank for tweakage.
Check TDC on all cylinders with a spark plug stop.
All the rockers are the same. Let me know because they are at my friends house on the mountain.

[rapidray]

Forged cranks are VERY hard to twist in that engine, unlike an unwelded 80/81 GS1100 crank. Worst case scenario, a bent rod but EXTREMELY rare to happen with that engine. If that is all the valves leak, just lap the valves because they AREN'T bent. Ray.

[TheCafeKid]

Forged cranks are VERY hard to twist in that engine, unlike an unwelded 80/81 GS1100 crank. Worst case scenario, a bent rod but EXTREMELY rare to happen with that engine. If that is all the valves leak, just lap the valves because they AREN'T bent. Ray.

Out of curiosity Ray (or Terry or Ed for that matter) I haven't done alot of work on the insert bearing stuff, but I have a couple of broken rocker arms i found in a pile of insert bearing motors/parts and was wondering how something like that could happen. I cannot recall if this was off of some 550 16v stuff I had laying around or 750/700 stuff. But what are other causes of this? Is it possible for the rockers to bind in the head at all? (again just wondering) and also, if hydrolock was indeed the culprit in this particular case, what sort of damage could be done to the shell bearings if any? I know you said the crank would be hard to twist but would that added load and pressure against the bearing warrant being checked at all? Just asking to learn.

[crapwacker]

The engine may of hydro-locked from gas in the oil.

Does the term hydro-lock refer to the cylinder being filled with fluid?

[rapidray]

Yes, it does. Ray.

[kirkn]

OUCH! Just running some preliminary parts pricing:

cam chain, 3 tensioner guides, 2 rocker arms, piston rings, complete engine gasket kit: $528.88, plus shipping from an online house. A bit more at another online house.

I'm hoping that gasket kit contains (at least) valve cover gasket, head gasket, base gasket, cylinder O-rings, base stud O-rings, 16 valve guide seals, clutch cover gasket, stator cover gasket.

Ouch!

[Macmatic]

I don't see them right now but I've seen DID cam chains on ebay for about $25 in the past. You could also buy up all the tensioner guide sets on there for about the cost of one new guide and at least two people in this thread have spoken up about rocker arms... don't spend more than ya have to unless you've got cash to burn.

/\/\ac

[kirkn]

Oh, yes, I WILL be taking someone up on the offer of rocker arms.

But I didn't see much on ebay for the 700. Somehow I must've missed 'em. I'll keep an eye on ebay.

Are any of these bits interchangeable with the 750?

[Macmatic]

Oh, yes, I WILL be taking someone up on the offer of rocker arms.

But I didn't see much on ebay for the 700. Somehow I must've missed 'em. I'll keep an eye on ebay.

Are any of these bits interchangeable with the 750?

To be sure check the part numbers at the fiche site of your choice, I like alpha-sports.com. I'm pretty sure the cam chain and cam chain guides are the same as the '83 GS750. When I looked an hour or so ago there were two sets of guides listed for the 700. I searched "gs700 cam"

/\/\ac

[Billy Ricks]

'83 and up GS750E and ES will be the same as the 700. There are only three parts I know of that are different between the two engines; rods, crank, and exhaust cam. The rods are actually longer on the 700 because the crank has a shorter throw. The exhaust cam was changed to add a little umph to the shorter stroked engine. Using a 700 cam in the 750 was a popular tweak back in the day.

[salty_monk]

Wonder how much oomph you got from that tweak... Anyone here tried it? Do you have to degree them or is it a straight drop in?

[rapidray]

Dan, you can drop them in but you will get more power if you take the time to degree them. Ray.

[kirkn]

Well, out of the handful of parts and gaskets I need so far, the fiches show that all are the same except the base gasket and the O-rings around the cylinder studs. The 700 has 'em and the 750 doesn't.

So, that opens up my searches a little.

Chugging right along...