That was freakin super awesome! Thanks for posting!
ST1300 Top End Engine Rebuild
- Thread starter AV8R
- Start date
bdalameda
PaleoCyclist
On Carbureted multi-cylinder bikes - If a main jet gets plugged slightly it is entirely possible to burn an exhaust valve from a too-lean condition. With the other cylinders still pulling hard it is hard to tell of the lean condition on the cylinder with plugged jets and so goes the exhaust valve. I've seen this before.
Dan
OP
OP
Sad but true.
Its the old lessor of two weavels.
Its the old lessor of two weavels.
I started in re-building my (VERY simple) 1976 Yamaha XS650C air cooled vertical twin last summer. The engine was running OK but the front cam chain guide had disintegrated and needed to be changed. I didn’t do any bottom-end work at all - just the timing chain guide plus, because I was in there, valves and rings plus a bore, hone and two new pistons.
As I said, the XS650 is about as simple an engine as was ever put into a motorcycle, especially when compared with an ST:
After the rebuild was done, it took maybe 45 minutes to re-install the engine from on-the-bench to started and running. Now, I will grant that the XS650 makes about 50 HP (versus 125 for the ST) and the bike will juuuusssttt break the ton (versus 240 km/hr / 140+ MPH for the big Honda) but the old Yamaha is an absolute blast to ride - and here’s the kicker about the rebuild job:
...as a result of a total failure of my bad knee and some factors at work, I ran out of time and had to farm the re-build out to a shop - and the bill was nearly $2000 CDN for labour and parts - and I supplied the gasket set which I had already bought.
If you started out to have an ST1300 engine rebuilt - I’d bet my hat that the bill would hit $4-6K without any problem and a fair bit more if you had the shop do the R&R on the engine and they did the job properly without damaging anything. My engine work was done by an excellent shop in London, Ontario called WolfeWorx and they did a superb job including vapour blasting the engine cases (that added maybe $250). Even if you did all the work yourself (except the machine shop stuff) I’ll bet it would still cost upwards of $2K in parts, depending on whether you needed new pistons etc. and it would be quite a task to NOT mess it up IMO. There are a zillion seals, gaskets, hoses, thingamajigs, doo-hickeys and watchamacallits that you will replace while you are in there - and they add up quickly.
When I priced having a Honda shop replace my clutch slave cylinder a couple of years ago, they wanted nearly $1800 for the job - most of which was labour to remove and reinstall the danged engine. The parts were quite a bit less than $100 (around $60-75 if I recall correctly). As we now know, the slave cylinder can fairly easily be replaced WITHOUT removing the engine - so that would have been a goodly sum (around $15-1700) wasted - to say nothing of the fact that getting the ST engine out and then back in without damaging anything would be...a challenge.
Anyhow - even if it ever became necessary, I sincerely doubt that there is any case in which rebuilding an ST1300 engine would ever make sense except as a very challenging and interestingly hobby project.
...just my $0.02 (which is around $14.37 CDN at the present rate of exchange).
Pete
As I said, the XS650 is about as simple an engine as was ever put into a motorcycle, especially when compared with an ST:
- two cylinders (not four) in a single finned barrel rather than a large, expensive and heavy cast block;
- ONE intake and ONE exhaust valve per cylinder (4 total versus 16 for the ST);
- One cylinder head (not two);
- One camshaft versus four camshafts in the ST;
- Simple screw & locknut adjusters (NO buckets or shims);
- Four cute little cast aluminium valve tappet covers held on with nuts (no tricky seals or gaskets or stupid little “maintenance” covers to worry about);
- All timing marks clearly visible (you can touch them with your fingers - no flashlights, or even torches
required); - NO balance shafts to synchronize;
- Air cooled (NO rad, NO thermostat, NO hoses, NO cooling passages anywhere);
- Two simple CV carbs which simply pop off the backside of the head (no EFI sensors / fuel pumps / HP fuel lines);
- Simple exhaust system - no electronics or O2 sensors - just a bunch of clamps, nuts and bolts;
- NO bodywork / plastic or other “ceremonial” parts at all;
After the rebuild was done, it took maybe 45 minutes to re-install the engine from on-the-bench to started and running. Now, I will grant that the XS650 makes about 50 HP (versus 125 for the ST) and the bike will juuuusssttt break the ton (versus 240 km/hr / 140+ MPH for the big Honda) but the old Yamaha is an absolute blast to ride - and here’s the kicker about the rebuild job:
...as a result of a total failure of my bad knee and some factors at work, I ran out of time and had to farm the re-build out to a shop - and the bill was nearly $2000 CDN for labour and parts - and I supplied the gasket set which I had already bought.
If you started out to have an ST1300 engine rebuilt - I’d bet my hat that the bill would hit $4-6K without any problem and a fair bit more if you had the shop do the R&R on the engine and they did the job properly without damaging anything. My engine work was done by an excellent shop in London, Ontario called WolfeWorx and they did a superb job including vapour blasting the engine cases (that added maybe $250). Even if you did all the work yourself (except the machine shop stuff) I’ll bet it would still cost upwards of $2K in parts, depending on whether you needed new pistons etc. and it would be quite a task to NOT mess it up IMO. There are a zillion seals, gaskets, hoses, thingamajigs, doo-hickeys and watchamacallits that you will replace while you are in there - and they add up quickly.
When I priced having a Honda shop replace my clutch slave cylinder a couple of years ago, they wanted nearly $1800 for the job - most of which was labour to remove and reinstall the danged engine. The parts were quite a bit less than $100 (around $60-75 if I recall correctly). As we now know, the slave cylinder can fairly easily be replaced WITHOUT removing the engine - so that would have been a goodly sum (around $15-1700) wasted - to say nothing of the fact that getting the ST engine out and then back in without damaging anything would be...a challenge.
Anyhow - even if it ever became necessary, I sincerely doubt that there is any case in which rebuilding an ST1300 engine would ever make sense except as a very challenging and interestingly hobby project.
...just my $0.02 (which is around $14.37 CDN at the present rate of exchange).
Pete
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wjbertrand
Ventura Highway
Just to add to what Doug said, Keep in mind this was like 15+ years ago and I never touched anything below the head gasket. I found the ST11's engine (and probably the same is true for the ST1300) to be pretty straightforward to disassemble and reassemble, still one of the sweetest sounds I ever heard was when that baby, with a little coaxing, fired back up and ran just like an ST should.
Someone on here had a bike that had a trashed cylinder head. Seems the someone let an airbox snorkle screw fall into the intake and then started the engine. You could see the screw impressions in the heads and piston.
After seeing prices for a new head from Honda and the work needed to get it into play he bought a new (used) engine and dropped it into place in one go.
After seeing prices for a new head from Honda and the work needed to get it into play he bought a new (used) engine and dropped it into place in one go.
wjbertrand
Ventura Highway
You both are right, two separate instances.
Yep... I was thinking that too... could remember seeing screw impressions... then I remembered the owner made the mechanic replace that valve shim one. So we don't know what all the costs were or what the mechanic went through.