GS700es broken timing chain.

[prichmon]

I just picked up a 700es with a broken timing chain and at least 1 broken rocker. I'll know more in a few weeks when I get time to tear it apart. I've never had a broken timing chain.

Could someone school me on best and worst case scenario at this point?
What should I watch for or specifically check for due to the damage?

Is there other engines which will bolt directly in? GS 550, 650? 750? 2 or 4 valve? 1000 or 1100? 2 or 4 valve?

I assume the closest would be the 700/750es and 700/750e. Followed by the 750 2 valves?

Thanks guys.

Rich

[Nessism]

750 2V is a completely different animal; much larger and heavier. Not interchangeable. You need a 3rd generation 750/700 engine.

As for what damage things like bent valves, broken rockers, valve guides, tensioner guides, and the like.

[greg78gs750]

might be worth investigating putting an 1100 in? NO IDEA if you can with a 700, but the 750/1100 swap is popular, so....

[Nessism]

might be worth investigating putting an 1100 in? NO IDEA if you can with a 700, but the 750/1100 swap is popular, so....

The 7-11 swap is applicable for the 2nd generation 750. The 3rd gen 750 engine is much smaller.

[prichmon]

What years are the 3rd gen?

What defines the 3rd gen engine? Are we talking gsxr 750/1100? Katana 750/1100?

I understand the gs 2 valve and early GS 4 valve.

Thanks

Rich

The 7-11 swap is applicable for the 2nd generation 750. The 3rd gen 750 engine is much smaller.

[Nessism]

The 3rd generation 750 was released in 1983. The motor is totally different from the 2nd gen engine that saw production between 1980-1983. 1983 was an overlap year where Suzuki sold bikes with either/or engine; the 2nd gen engine went into the Katana (M) and T model bikes and the 3rd gen engine went into the E and ES.

The 2nd gen 750 engine is one of the very few GS engines that wasn't bulletproof. There was an oiling system weakness which lead to tore up cams/rockers and/or crank bearings. There was a fix to shim the oil pressure relief spring but I'm not sure if that in of itself solved the problem.

[prichmon]

what years am I lloking for for the 3rd gen? 700/750 1983-????

Does it only apply to e/es engines?

Thanks for the replies guys.

Rich

[prichmon]

What years are the 3rd gen engines?
Are the early GSXR the same gen or it's own entity.
What years should I look for 1983-???
Is there a larger engine swap which bolts in?

Thank you.

Rich

[Nessism]

Partzilla has a parts fishe that shows what parts fit what year bikes.

[prichmon]

Thanks Nessism. I appreciate it.

[GregT]

The 3rd generation 750 was released in 1983. The motor is totally different from the 2nd gen engine that saw production between 1980-1983. 1983 was an overlap year where Suzuki sold bikes with either/or engine; the 2nd gen engine went into the Katana (M) and T model bikes and the 3rd gen engine went into the E and ES.

The 2nd gen 750 engine is one of the very few GS engines that wasn't bulletproof. There was an oiling system weakness which lead to tore up cams/rockers and/or crank bearings. There was a fix to shim the oil pressure relief spring but I'm not sure if that in of itself solved the problem.

It doesn't solve it totally. I've got a late ES 750 engine apart awaiting valves and have been able to compare some parts with the gen 2. The oil pump is exactly the same. The ES relief valve appears to be non serviceable - IE won't come apart for shimming. The ES setup actually asks more of the pump with an oil cooler and oil sprays under the pistons. As you might therefore expect, this ex race engine is showing signs of bearing distress too.
I hope shortly to be able to compare the late ES with an early GSXR750 to establish what changes Suzuki made between the two. The GSXR is pretty good in the lubrication department. I want to look at oil gallery sizes and pump rotor dimensions as well as the drive ratio. If there's a feasible upgrade I can find I'll say so - after I've done it for this engine.

[prichmon]

GregT could you email me when you know something? I'm a few weeks from tearing apart my ES to decipher the extent of the damage. I would love to hear your thoughts on the oil system.

Thanks.

It doesn't solve it totally. I've got a late ES 750 engine apart awaiting valves and have been able to compare some parts with the gen 2. The oil pump is exactly the same. The ES relief valve appears to be non serviceable - IE won't come apart for shimming. The ES setup actually asks more of the pump with an oil cooler and oil sprays under the pistons. As you might therefore expect, this ex race engine is showing signs of bearing distress too.
I hope shortly to be able to compare the late ES with an early GSXR750 to establish what changes Suzuki made between the two. The GSXR is pretty good in the lubrication department. I want to look at oil gallery sizes and pump rotor dimensions as well as the drive ratio. If there's a feasible upgrade I can find I'll say so - after I've done it for this engine.

[GregT]

GregT could you email me when you know something? I'm a few weeks from tearing apart my ES to decipher the extent of the damage. I would love to hear your thoughts on the oil system.

Thanks.

I'll post up on here when I have any useful information. Bear in mind I'm usually dealing with extreme use - I build mainly race engines these days. For the average user in normal road conditions, stock is usually satisfactory.
I'll be interested to see what you find as to the reasons why it broke the camchain

[prichmon]

According to parts fiche 83-85 only.

Thanks all.

[prichmon]

I got the 700es pulled apart tonight. #1 and 4 exhaust rockers are broken. Timing chain is out. I blew compressed air in the cylinders to see if they will hold any pressure. #4 was not holding much pressure.

Is there any way to see if the valves were bent? Or if a piston is damaged without pulling the head?

I would like recommendations on aftermarket timing chain and tool please. I would prefer not to split the cases.

Thasnk you

RR