GS500 woes and engine design fault ???

[cestrian]

I decided to paint my exhaust on my GS500 last week and....well here's the story so far.....

One of the hex bolts (into the cylinder head) was loose, one was very tight, one was OK and the last one snapped, aaarrrggghh!
So I drill out the snapped bolt and tried an 'easy out' or screw extractor to remove the remains of the bolt. The easy out snapped so I drilled it out (took two hours and 7 expensive drill bits).
The next easy out snaps too. Now I'm getting really miffed.
OK I'm a businessman and so decided it wasn't worth my time drilling out another 'east out' so I ordered a cylinder head as a replacement for the knackered one.

Today I removed the cylinder head (no problem) but as usual dislodged the cylinder bores from the crank casing. When I tried to reposition the bores down onto the crank casing I noticed the bores were rocking side-to-side. Upon inspection I found grit between the mating surfaces of the crank case and the bores. And one of the studs was slightly corroded.
I decided the only course of action was to remove the bores, clean the whole thing up and start again. The was a fair amount of grit stuck in the bolt holes (in the bore casings) and it was a bugga to clean.

Anyway, after a serious clean-up, a fixed up gasket and some Hylomar blue, we're ready to put the Cylinder head on tomorrow evening.

All I wanted to do was paint my exhaust.

g)

[sickpup]

I don't think you should work on bikes ever again.

All you had to do was remove the head, drill and rethread.

Easy outs break really easily and expand the bolt you put them into wedging them tighter.

As to the bores there could only be grit between them due to a previous bad rebuild or your work. Grit couldn't get between a clamped surface.

What design fault?

Sorry this seems very negative but I think inexperience plays a large part here.

[cestrian]

"I don't think you should work on bikes ever again. " - Sickpup.

Not sure I can be bothered after this job.

"As to the bores there could only be grit between them due to a previous bad rebuild or your work. Grit couldn't get between a clamped surface" - Sickpup

I should clarify...

The grit fell onto the surface as soon as the bore was dislodged. I guess not knowing the grit was likely to be there was my main problem.

The possible design fault....The grit collects over time and also holds water/moisture around two of the studs causing them to corrode. The area in question sits directly behind the front wheel.
If the stud was completey encased, grit would never find its way to the studs.
Actually I just popped downstairs to refresh my memory on this job and the two front central studs are completely bare and subject to the weather and collection of road dirt/grit. Definitely not a design feature, wouldn't you say?

g)

[stinkwheel]

Well, if I get what you are describing correctly, it is a design feature to be found on virtually every motorbike on the roads today.

If you can find some, replace the nuts with brass ones. These shouldn't seize on and even if they do, the thread should strip out of the nut (which cost 20p to buy) before the stud shears.

[sickpup]

The exhaust studs as stinkwheel says are a design common to virtually every bike on the road as well as most cars. Studs are used as they cause less stress on the cylinder head than bolts and tend not to fail in the way springs do.

There will always be grit and dirt on the outside of an engine unless you clean it religously. Whenever doing work on a bike you should clean it first.

Never use easy outs.

[cestrian]

I don't seem to have explained the situation too well.

The studs with the grit (and corrosion too) are the studs which hold the bores and cylinder head in place, not the exhaust. The exhaust is secured with hex bolts.
Hence, when the bores are removed, one gets a pile of grit and rust landing on the mating surface and perhaps a little falls into the casing.
I just spoke to a Suzuki technician and he said "it's normal for that model, it's a pain in the arse and theres nothing you can do about it".
Lesson learned and I hope this helps someone who ever needs to do a similar job.

Regards

g)

[stinkwheel]

[cestrian]

Hi again, thanks for your reply.

Collected a set of Hex bolts for the exhaust today along with a head gasket. The hex bolts had a part number for the GS500 so they must be the correct fasteners.
The bike is almost complete, perhaps another hour of work tomorrow morning.

Point taken about the 'easy outs'.

regards

g)

[Jubal]

As previously stated clean everything up as much as possible prior to stripping down any top-end, even if you have use a small paint brush and vacuum cleaner after degrasing, obviously let it dry off before hand, rod out the stud holes in the barrel/head before reassembly as further crap will drop out. It's well worth getting an old vacuum to keep around the garage, they work well on crap around the sparkplugs also.
Giving the bolts/studs a coat of Copperslip will make life a lot easier next time.

[KatOwner]

It's a lesson usually learnt the hard way .... ALWAYS clean the bike before you start any job

The less muck on the machine... the less likely it is to cause problems. I also have a nice big bottle of WD40. Spray it liberally around any bolts you plan to undo the night before you start work.

Finally...when trying to shift bolts....a few basic lessons in physics can help:

Aluminium and alloys expand more than steel/cast iron.

If you have a steel bolt in an aloy casting....try undoing it when it's hot. The heat will expand the alloy more than the steel bolt and loosen it. If, however, it's a steel nut on a steel stud...do it cold.

p.s. MIND YOUR FINGERS! Hot metal and all that

[cestrian]

Hi Katowner,
glad to report the engine is back together now and started well first time. After about a minute the bike started to pop and fart but it was due to fuel starvation. A gallon of juice sorted it out. Bike is now running quite well, certainly sounds good. I think I'll get the bike in for a tune-up before I use it on the road.

Thanks for the tips.

g)

[KatOwner]

Good to hear it's back together and running nicely

[cestrian]

Thanks.

Just went outside, started it up, ran ropey for a couple of minutes then once it had warmed up, choke OFF and it seems to be running really nicely. Immediate response to the throttle, runs very evenly on tick over, feeling very happy with myself today.

I have the bike booked in to the local bikeshop/workshop for the job to be done, but now that I have fixed it myself I was wondering if I should let them have it for an hour for a tune up. Do you think it would be worth it or would I be wasting my money? I'm wondering, is there anything to tune up, or should I simply give it a new set of spark plugs and an oil & filter change and just ride it.

g)

[stinkwheel]

If you've done a top-end rebuild yourself, anything else would be a piece of piss.

I suppose the only thing would be having access to vacuum guages to balance the carbs, but you could probably buy a set for the same price as you would pay a garage to do it for you.

[edd]

make a water manometer for virtually nothing https://www.obairlann.net/~reaper/motorcycle/manometer.html thats what i use and it works a treat. Some people say they have had problems but mine has worked on all the bikes ive had.
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