Topic: I received an 81 Suzuki GS450E, I want to go 3.5mm over.

[grcamna2]

I did a few(almost 30hrs.)good hours of 'free' mobile repair.. on a guy's 250.
He gave me a 'free' 81' Suzuki GS450E that needs work.
The bike was owned by one owner in S.F. who just used the bike while somewhat/mostly neglecting it. The man who I worked for goes to charity auctions.. 

Doesn't look like the PO ever torqued down the cylinder head.. and it will need new top-end gaskets and the top-end freshened-up.
The GS450(71mm bore)and 89'- GS500(74mm bore)model twins both share the exact same stroke of 56.6mm,therefore I purchased a GS500E cylinder block and the bores are in very good condition & GS500E cam chain tensioners and am now researching which 74+mm pistons will be best to match the dome shape of the STD OEM GS450 pistons while trying to not exceed 10:1 CR with Ca. pump g'ass'oline.

I don't mind having the domes of my intended pistons milled-down a little so as not to exceed my target CR by too much,if they need it.

The stock GS500E pistons may be a choice..;I just need to figure-out a way to measure the displacement of each piston's dome.. Have any of you tried to measure their piston's dome displacement?  possibly dipping just the dome into a liquid,then comparing with the original?

I plan to restore the bike and keep it;I prefer to keep it mostly stock(stock ports,cams,carbs,exhaust,etc.) w/ the exception of the over-bore pistons.

 Do any of you Honda SOHC members know the Suzuki GS450 or GS500 twins ?
 Or possibly familiar with making a piston swap from one engine to another engine(I'll be using the stock GS450 head)with an improvement in all-around power by matching the dome shape as close as possible to the original spec pistons ?   thanks,Bill 

[grcamna2]

The piston(OEM Suzuki STD 71mm)on the left is the GS450 stock piston and the one on the right(OEM Suzuki STD 74mm)is the GS500E stock piston;the piston pins are 18mm on these.

The stock GS450 piston's dome shape looks very similar  to certain early 80's Kawasaki pistons..

The GS450 has 9:1 CR and the GS500E has 9.2:1 CR
I have looked for aftermarket Suzuki GS500E pistons,but so far have 'struck out'.

I'm looking for piston recommendations on pistons(ideally 74.5mm with overbore capability for later when it wears)that will work for my(GS450)application;I found that all models of Suzuki GS450 2 valve per cylinder use the same pistons.
I can measure these pistons for reference,thanks.

[Leino]

8-valve GS 1000 oversize pistons.

[grcamna2]

8-valve GS 1000 oversize pistons.

Oh?  Does there exist a set of 8-valve GS1000 OEM pistons of 74+mm ??
I have been looking..

[Leino]

8-valve GS 1000 oversize pistons.

Oh?  Does there exist a set of 8-valve GS1000 OEM pistons of 74+mm ??
I have been looking..

75mm must exist as I've used them on a forgotten era road racing bike 

[Leino]

They were made by Wiseco I believe, not OEM and forget about the one more oversize stuff. The bike is too boring to ride even with the engine work done to keep a grown man interested.

More like a riding simulator, everything works like on a real motorcycle, it's just slow and boring.

[grcamna2]

8-valve GS 1000 oversize pistons.

Oh?  Does there exist a set of 8-valve GS1000 OEM pistons of 74+mm ??
I have been looking..

75mm must exist as I've used them on a forgotten era road racing bike 

I appreciate your information 

[grcamna2]

They were made by Wiseco I believe, not OEM and forget about the one more oversize stuff. The bike is too boring to ride even with the engine work done to keep a grown man interested.

More like a riding simulator, everything works like on a real motorcycle, it's just slow and boring.

  Lol  I know you're 'hooked' on the GS1100E engine 
I looked on ebay and they're selling a Wiseco '1100' kit(73.50mm)for the GS1000.
A pair of 74.25mm - 75mm GS1000E piston kits may be 'in my future' .  if I can locate two of them;possibly some 'old stock' somewhere. I'm glad to know that GS1000 is an option.

I would like to find access to many various used pistons,where I could measure them and compare them to the ones I have;it's possible a set of Kawasaki GPZ or KZ? pistons will come close enough.
The search is challenging.

[Leino]

With stock cams dialed in and a pair of second hand Dellorto carbs and some crappy megaphone exhaust it made pretty much the same HP at the wheel factory promised at the crank so it runs ok for a light bike 

[grcamna2]

With stock cams dialed in and a pair of second hand Dellorto carbs and some crappy megaphone exhaust it made pretty much the same HP at the wheel factory promised at the crank so it runs ok for a light bike 

1983' GS1100E ?

[Leino]

With stock cams dialed in and a pair of second hand Dellorto carbs and some crappy megaphone exhaust it made pretty much the same HP at the wheel factory promised at the crank so it runs ok for a light bike 

1983' GS1100E ?

GS 450 with 73,5mm Wisecos we used because they were cheap and in stock. I used the 75mm pistons (now that I checked I bought them from APE but are made by Wiseco) on a late 70's GS 1000 based race bike.

[grcamna2]

With stock cams dialed in and a pair of second hand Dellorto carbs and some crappy megaphone exhaust it made pretty much the same HP at the wheel factory promised at the crank so it runs ok for a light bike 

1983' GS1100E ?

GS 450 with 73,5mm Wisecos we used because they were cheap and in stock. I used the 75mm pistons (now that I checked I bought them from APE but are made by Wiseco) on a late 70's GS 1000 based race bike.

 

[Leino]

GS 450 or is it 480 now is my friends "coffee run bike". He wanted something light and maneuverable to ride around town and twisties.

It was pretty, very pretty, GULF inspired paintjob, cafe racer style but the engine gave up after about 50-60km of riding.
I pulled the engine and had a peek just to find out someone left some of the crankcase bolts out and used a whole tube of silicone to block the oil from going anywhere. Rod bearing had spun and destroyed the crank.
There wasn't much to salvage so my friend bought another engine, ported the head a bit, 73,5mm Wisecos and just some tweaking to make it even slightly quicker. We would have used the 75mm pistons but couldn't bother ordering them from the US as I knew our local dealer had some 73,5mm pistons in stock for a very decent price 

The bike ended up running pretty good for a small displacement oldskool thingy with nothing fancy in it.
45hp at the wheel if my memory serves me right and it's good for 100mph+ easily.

[grcamna2]

GS 450 or is it 480 now is my friends "coffee run bike". He wanted something light and maneuverable to ride around town and twisties.

It was pretty, very pretty, GULF inspired paintjob, cafe racer style but the engine gave up after about 50-60km of riding.
I pulled the engine and had a peek just to find out someone left some of the crankcase bolts out and used a whole tube of silicone to block the oil from going anywhere. Rod bearing had spun and destroyed the crank.
There wasn't much to salvage so my friend bought another engine, ported the head a bit, 73,5mm Wisecos and just some tweaking to make it even slightly quicker. We would have used the 75mm pistons but couldn't bother ordering them from the US as I knew our local dealer had some 73,5mm pistons in stock for a very decent price 

The bike ended up running pretty good for a small displacement oldskool thingy with nothing fancy in it.
45hp at the wheel if my memory serves me right and it's good for 100mph+ easily.

Ok Leino, you installed the 73.5mm Wisecos meant for the GS1000 and they fit the GS450's combustion chambers w/o needing to trim the crowns ?
Can you remember what octane ethanol? gasoline was required to run that engine ?

[Stev-o]

He gave me a 'free' 81' Suzuki GS450E that needs work.

This is the bike you've been wanting, right? You finally found one....got pics?

[grcamna2]

He gave me a 'free' 81' Suzuki GS450E that needs work.

This is the bike you've been wanting, right? You finally found one....got pics?

Yes it is Stev-o 

I'll take some pics but I'm kind of ashamed  how it looks presently;the exhausts are rusted-out from the PO's short trips in S.F. and the sidecovers need work. 
Ah,I guess you don't care how it looks now? because it is 'under construction' presently.. I'll take some 'before' pics soon 

I'm working on it a bit,as I can..
I have it under a cover in my parking space which is where I can work on it:the neighbor is keeping me under surveillance,then reporting me to the manager.
I have a replacement exhaust up inside my 2nd floor apt and it's cleaning up well,plus I'm working on another clutch cover & getting it ready to be polished.
I had hoped to get a 1st Floor apt,but 'it is what it is' until I find a better place I can afford.

[Leino]

GS 450 or is it 480 now is my friends "coffee run bike". He wanted something light and maneuverable to ride around town and twisties.

It was pretty, very pretty, GULF inspired paintjob, cafe racer style but the engine gave up after about 50-60km of riding.
I pulled the engine and had a peek just to find out someone left some of the crankcase bolts out and used a whole tube of silicone to block the oil from going anywhere. Rod bearing had spun and destroyed the crank.
There wasn't much to salvage so my friend bought another engine, ported the head a bit, 73,5mm Wisecos and just some tweaking to make it even slightly quicker. We would have used the 75mm pistons but couldn't bother ordering them from the US as I knew our local dealer had some 73,5mm pistons in stock for a very decent price 

The bike ended up running pretty good for a small displacement oldskool thingy with nothing fancy in it.
45hp at the wheel if my memory serves me right and it's good for 100mph+ easily.

Ok Leino, you installed the 73.5mm Wisecos meant for the GS1000 and they fit the GS450's combustion chambers w/o needing to trim the crowns ?
Can you remember what octane ethanol? gasoline was required to run that engine ?

Compression isn't anywhere close to extreme with those pistons. Just regular pump gas.

[Leino]

If you end up milling the head, check valve pockets carefully... well, check them anyway 

[grcamna2]

If you end up milling the head, check valve pockets carefully... well, check them anyway 

I understand what you said in your last post and in this one;I plan to keep the head stock.
I appreciate you. 

I'll 'clay' the pistons to check.

[Alan F.]

I think it's great that you finally found the bike you were looking for. Even if its a rehab project, you'll make it what you need it to be. I completely sympathize about working in a single parking space, I'm doing the same and not enjoying it much but it's what I have to work with too.
Thank for sharing this project with us.

[grcamna2]

I think it's great that you finally found the bike you were looking for. Even if its a rehab project, you'll make it what you need it to be. I completely sympathize about working in a single parking space, I'm doing the same and not enjoying it much but it's what I have to work with too.
Thank for sharing this project with us.

Hi Alan 
Yeah,I was looking through Sacramento CL and saw the bike for sale;looked ok plus it was the model i was looking for..
The man was asking 800 obo so I rode out w/ my small(full)service call tool box on the back of my Honda. I spoke w/ the guy then and(the bike didn't run)decided to do the deal of working on his 07' Kaw. ZX250 ninja;I promised the man I would get his 250 "running like a Swiss watch"  and I had 'my work cut out  of me' literally while I was there..  I was there for 4+ days.
 What a drag working for the man on his property for free,kind'of..    there was some serious negative energy flowing around that property.

The man called me back after about 10 days and asked me back($,right?)to his property to work on the bike.. he told me it didn't run.
I dumped all the contents of the tank into a 5gal. bucket and it had some CRAP in it(I had previously given it a gentle flush and it looked all good),I meticulously cleaned the carbs(again)and used a pack of BB's on the inside of his tank to get Every last bit out; plus the guy had a new/weak(no activation charge while he did PLENTY of cranking on his own)battery and it kept fouling plugs.  This was another 1.5 days of work on it.

I was working on the agreement with him that 'it was a friendly deal'   To ME that meant 'one hand washes the other' to keep things on the 'up and up'   To him,well he didn't feel he owed me any $..  but because of all the extra work I did,I know he did.
I wasn't thinking serious business with a written estimate,etc. on this one:I wanted a 'friendly deal' and the guy seemed like he was agreeing with me. He must have taken me for a 'chump'. 

The man is moving to FL. next month;I 'liberated' the 81' GS450E from him and I AM going to get it to run great,after a $ fashion. Done deal. 

[Stev-o]

So, how did the "Friendly deal" work out?   

Years ago, I had a similar deal and the fuc*er burned me.  Have been cautious ever since.

[Kelly E]

How about some before pictures of the GS 450?

[grcamna2]

This bike was near the ocean and did get corroded.

I have other pics but I was only able to upload to upload a couple.. from my computer:image size.
I haven't done the photo hosting thing yet.

[Stev-o]

This bike was near the ocean and did get corroded.

Looks better than I imagined after your description...