Topic: Terry's Boneyard Barn find Budget Suzuki T500 Reanimation.

[jgger]

Doing that sharp edge on the transfer port helps a ton! I did exactally as the boys have suggested to my old 250 Montesa dirt bike back in the day and had to drop 2 full jet sizes and increased my miles per tank by about 20 to 25 miles. Those are Desert racing miles, not Sunday cruising down the hiway miles.

When you grind the intake and transfers leave them rough, don't polish them Shiney. This helps to atomize the fuel mixture. On the exhaust port shine that up like a mirror,  it really helps dump the burnt fuel.

If you want a cheap and easy way to raise the exhaust port you can file the top of the piston on a slope to match the width of the exhaust port. That way if you screw it up you just replace the piston. Re-sleeving a 2 stroke is much more complicated than a 4 stroke!

[Zunspec]

Doing that sharp edge on the transfer port helps a ton! I did exactally as the boys have suggested to my old 250 Montesa dirt bike back in the day and had to drop 2 full jet sizes and increased my miles per tank by about 20 to 25 miles. Those are Desert racing miles, not Sunday cruising down the hiway miles.

Geoff - Sharp edges to the any of the ports will result in premature ring wear.  A must when receiving a freshly re-bored 2-st barrel is to chamfer the ports to remove the "sharp" edge from the ports. For the same reason ports have a curve to their corners,

When you grind the intake and transfers leave them rough, don't polish them Shiney. This helps to atomize the fuel mixture. On the exhaust port shine that up like a mirror,  it really helps dump the burnt fuel.

Geoff - The same rough finish to the inlets is applicable to both 2 and 4st.  A mirror finish exhaust port also helps to prevent any carbon build up.

If you want a cheap and easy way to raise the exhaust port you can file the top of the piston on a slope to match the width of the exhaust port. That way if you screw it up you just replace the piston. Re-sleeving a 2 stroke is much more complicated than a 4 stroke!

Geoff - I have seen this method used on production pistons made for the Yam TY250 trials bike where the slope is part of the piston casting.  Easier to facilitate than reworking 5000 already prepared barrels if the porting needs tweaking .  Seen on the inlet transfer ports though, not seen it on exhaust ports.  The liners in the T/GT500 barrels have a ridge, top and bottom,  and must be cast in place with the barrels.  To remove them requires machining, they can't just be pressed out.  A friend in the USA is doing this to install his own "multi" port sleeves.

Cheers  Geoff

[simon#42]

Terry , I have been building racing two stroke engines for over 40 years and I would advise you ignore all of the above advice !

[Terry in Australia]

Beautiful work Geoff, I'm always impressed with the efforts some guys make to continually improve old bikes like ours. I was gutted tonight, I was pulling parts out of the tub to reinstall when I discovered that somehow I've lost a part? Aggghhh!!!! I jumped on the interwebs tonight and it looks like CMSNL have them, but what a PITA! I think I'll make one. More tomorrow.

T500 missing link Friday 17 Sep 2021 1 by Terry Prendergast, on Flickr

[Terry in Australia]

Terry , I have been building racing two stroke engines for over 40 years and I would advise you ignore all of the above advice !

Oh, OK, will do! (to be honest I'd sort of decided to leave it as is, and maybe do some "tuning" after I've experienced it in stock trim)

[Zunspec]

Terry , I have been building racing two stroke engines for over 40 years and I would advise you ignore all of the above advice !

Care to expand on that, Simon.  Where have I been been going wrong all these years lol 

Cheers  Geoff

[Terry in Australia]

Fight! Fight!

[Zunspec]

I have some of those plates kicking around somewhere.  If you PM a delivery address I'll post one off to you.

Cheers  Geoff

[Zunspec]

Fight! Fight!

LOL 

Not at all, I'll soak up any fresh info. gladly.  It helps to understand the reasons though.

Cheers  Geoff

[Terry in Australia]

I have some of those plates kicking around somewhere.  If you PM a delivery address I'll post one off to you.

Cheers  Geoff

Hey thanks Geoff! I think I'm OK though, I put a "wanted" post of the Suzuki twins FB page for a gear lever for the T500 and a guy in Queensland has one for me, plus the plate, so he's gonna mail it to me tomorrow. I think I'll still make one, just for fun.

[Terry in Australia]

Damn! Now I want a V8 2 stroke car with 8 expansion chambers and EFI!

[ekpent]

 Too bad you don't have many old snowmobiles sitting around OZ if that's where the engine started life.  Be nice for running around the desert in the outback !!  https://www.facebook.com/marketplace/item/1702036946668923/?ref=saved&referral_code=null

[RAFster122s]

Damn! Now I want a V8 2 stroke car with 8 expansion chambers and EFI!

That started life as a Volvo 122S 2 door!

[grcamna2]

Doing that sharp edge on the transfer port helps a ton! I did exactally as the boys have suggested to my old 250 Montesa dirt bike back in the day and had to drop 2 full jet sizes and increased my miles per tank by about 20 to 25 miles. Those are Desert racing miles, not Sunday cruising down the hiway miles.

Geoff - Sharp edges to the any of the ports will result in premature ring wear.  A must when receiving a freshly re-bored 2-st barrel is to chamfer the ports to remove the "sharp" edge from the ports. For the same reason ports have a curve to their corners,

When you grind the intake and transfers leave them rough, don't polish them Shiney. This helps to atomize the fuel mixture. On the exhaust port shine that up like a mirror,  it really helps dump the burnt fuel.

Geoff - The same rough finish to the inlets is applicable to both 2 and 4st.  A mirror finish exhaust port also helps to prevent any carbon build up.

If you want a cheap and easy way to raise the exhaust port you can file the top of the piston on a slope to match the width of the exhaust port. That way if you screw it up you just replace the piston. Re-sleeving a 2 stroke is much more complicated than a 4 stroke!

Geoff - I have seen this method used on production pistons made for the Yam TY250 trials bike where the slope is part of the piston casting.  Easier to facilitate than reworking 5000 already prepared barrels if the porting needs tweaking .  Seen on the inlet transfer ports though, not seen it on exhaust ports.  The liners in the T/GT500 barrels have a ridge, top and bottom,  and must be cast in place with the barrels.  To remove them requires machining, they can't just be pressed out.  A friend in the USA is doing this to install his own "multi" port sleeves.

Cheers  Geoff

Geoff,I like that sleeve that your friend has;how have they been for him ?

[PeWe]

Also known as Volvo Amazon here in Sweden were it was created and built.

[Zunspec]

[quote

Geoff,I like that sleeve that your friend has; how have they been for him ?
[/quote]

Hi  grcamna2,

The photo is of the template/pattern used to mark the positions of the ports on an un-machined liner.  However you can see the intent.   Ken Lavallee has raced his engine with the new multi-port barrels and they have performed well.  He may offer them for sale after a bit more R&D (he's always coming up with new ideas)

Cheers  Geoff

[RAFster122s]

Also known as Volvo Amazon here in Sweden were it was created and built.

Here as well, but they lost the ability to call them the Amazon due to a bicycle company having registered the name and they had to quit using the name.

Owned a 66 from 93 until 2010...wish I still had it.

[grcamna2]

[quote

Geoff,I like that sleeve that your friend has; how have they been for him ?

Hi  grcamna2,

The photo is of the template/pattern used to mark the positions of the ports on an un-machined liner.  However you can see the intent.   Ken Lavallee has raced his engine with the new multi-port barrels and they have performed well.  He may offer them for sale after a bit more R&D (he's always coming up with new ideas)

Cheers  Geoff
[/quote]

Geoff,I owned a few Yamaha RD350s from the early 70's and they have a 7-port engine which gave those little(peaky)2-stroke engines All kinds of 'kick'.They breathe much better and the reed valves helped to keep them from 'falling on their face' if they weren't in their 'sweet spot'/rpm powerband,especially the ones that were ported.They had nowhere near the amount of grunt the T500 has.

[Zunspec]

Hi grcamna2,

The T/GT 500 only has 2 transfer ports, it's a design from the mid 1960s  .  Saying that it is a torquey engine and is only red-lined at 7000 rpm.  Helped no doubt by those extra 150cc over the 350 Yamaha.  The RD series Yams were another generation of engine compared to the T500 and their more sporty performance reflects this.  I loved my RD350LC, one of the best bikes I owned for the roads I frequent (lots of twisties). 

Cheers  Geoff

[Terry in Australia]

So absolutely miserable weather here in the last 36 hours, icy cold, gale force winds, and rain coming in sideways. I hate days like today, but what to do, stay inside my nice warm house and hide? Well the T500 isn't going to build itself apparently, so after I took Greg's (Disco here) CB750 rear hub to the Post Office, then went around to the nut and bolt shop to pick up some replacement screws for the ones I had to drill out when I pulled the engine apart, I marched bravely into the misery of a Melbourne "Spring", and got stuck into it.

I did one last check to make sure I hadn't left anything out, then applied some case sealant to the top case, and while it cured a tad, I took the 20 case bolts with their flat washers and spring washers into my garage, and used the wire wheel attachment on my pedestal grinder (the "Face Breaker") to clean the rust and gunge off each bolt. I know that there are 20 case bolts, because Suzuki conveniently marked each bolt hole with the tightening sequence. I would never have known this if I hadn't had the cases vapor blasted, but it does make the job easier. Kawasaki do it too, but I haven't seen it on Honda engines, more's the pity.

T500 Saturday 18 Sep 2021 by Terry Prendergast, on Flickr 

Anyway, I successfully laid the top case on the bottom without getting case sealant all over my digits, and was happy that once torqued down, there were no gaps and no binding of the various shafts.

T500 Saturday 18 Sep 2021 1 by Terry Prendergast, on Flickr

I found the three threaded plugs and torqued them down too, and called it good.

T500 Saturday 18 Sep 2021 2 by Terry Prendergast, on Flickr

I took all the disgusting head bolts and cylinder stud nuts into the garage and cleaned them all up on the wire wheel again, along with all of the washers. By this time I was freezing cold sick of it, so I decided to wait until tomorrow to install the pistons, hone the bores, and install the cylinders and heads. Hopefully tomorrow the weather will be a little more agreeable.  

[grcamna2]

That's nice work Terry 
I'm curious what type of cylinder hone you use?

Have they lifted the 'shelter at home' Covid warnings?

[MauiK3]

Good progress, sorry for the weather. Aren’t you guys headed for summer?

[Terry in Australia]

Thanks guys, I'm hoping the wind dies down in the next couple of hours, as it's howling thru my "Winter Workshop" in the patio at the moment, and it's freezing. September is always a crap shoot as the weather vaccilates between cold winter days and occasional warm ones, but hopefully this cold spell will pass quickly, as apart from a few essential parts, I have almost enough bits to put it back together, and while I think we'll still be locked down for the next few weeks, I'll do some "shakeout rides" around my local streets in preparation to getting it registered.

Bill, I own several hones, a ball hone, a couple of 4 stone hones which are great for finishing a cylinder after boring, or even taking one out to the next oversize. For this job though I'll just be using my spring loaded 3 stone hone to clean up the bores which looked pretty good when I looked at them last, they've been bored out to 71mm and the pistons looked really good, but I bought new Cruizinimage pistons and rings, needle roller bearings etc because they worked well in the T350 and are cheap. (like me) All going well I'll have the engine back together today, if this weather calms down a tad.......

[grcamna2]

Thanks guys, I'm hoping the wind dies down in the next couple of hours, as it's howling thru my "Winter Workshop" in the patio at the moment, and it's freezing. September is always a crap shoot as the weather vaccilates between cold winter days and occasional warm ones, but hopefully this cold spell will pass quickly, as apart from a few essential parts, I have almost enough bits to put it back together, and while I think we'll still be locked down for the next few weeks, I'll do some "shakeout rides" around my local streets in preparation to getting it registered.

Bill, I own several hones, a ball hone, a couple of 4 stone hones which are great for finishing a cylinder after boring, or even taking one out to the next oversize. For this job though I'll just be using my spring loaded 3 stone hone to clean up the bores which looked pretty good when I looked at them last, they've been bored out to 71mm and the pistons looked really good, but I bought new Cruizinimage pistons and rings, needle roller bearings etc because they worked well in the T350 and are cheap. (like me) All going well I'll have the engine back together today, if this weather calms down a tad.......

I hope to purchase($$$)a quality precision 4-stone hone with different grit sets of stones at some point,along with some nice i.d. measure inside and outside micrometers.What I like about the 4-stone hones Terry is that all those 4 stones feed-out evenly to where there's even pressure on all of them and it cuts 'true' and 'even':compared to my 3-stone spring loaded 'glaze breaker' hone which needs just the right spring tension adjustment and exact 'centering' stroke-style to keep it 'true'.

A ball-bead hone used quickly toward the end of the honing/measuring process helps to soften some of the sharp edges on the ports which could possibly catch the edge of a piston ring if left sharp.

[Terry in Australia]

Thanks Bill, my sleeves have been bored and used (no idea why the top end was off the engine when I got it) so I'm only honing them to clean them up. I'll have a look at the ports to see if there are any sharp edges, but I doubt it.