Opinions Please: Replace GT186 kit with............??

[Donnie]

............??????

And here is why.

IMG_1310 1 by Donnie Canning, on Flickr

This happened last year when i tapped the top of a speed bump in france, I had it all rewelded but looks like it didnt hold and Ive just run it all in again and got back from france again Sunday.

Enough is enough, Im dumping the kit due to the exhaust port weak design, Ive had enough.

Question is where to go from here.

Easiest thing is to stay small block spacing in which case Im going Imola / RB20 to keep a reed valve or BGM RT195 with no reed valve, is there any Ive missed (not interested in going mugello)

Alternative would be have the casing converted to 200 stud spacing and go for something like an old school honda 205 but im not sure I can be doing with all that running in again frankly.

So, Im going to concentrate first of all on a alloy/nicasil kit that will do a genuine 60mph with possible spurts to 70 with either a clubman style pipe or expansion and a 30mmPHBH carb. On a Series 2 with a 16.5 stone bloke that primarily wants it for touring if that makes sense.

I appeal to you all that have had any of the above kits and would recommend or warn me about possible weaknesses (I was completely unaware of the exhaust port issue on the GT or I would probably have not bothered to be honest.)

[ToBoldlyGo]

What about the RT kits Donnie? Well engineered and flexible. I rate the Casa 185 as well. Although some say it is a little conservative.

[Donnie]

Im leaning toward the RT195 the more googling I do I have to admit.

Anyone know of any issues that they have had or suffer from?

[Scooterdude]

Just in the middle of fitting an RT kit, did the first one a couple of weeks ago both using a Pro Porting 60/110 crank and both running a Delortto PHBH 28 carb. The one that's running is lovely, running open carb (and without any spitback whatsoever!) and a KB clubman, loads of torque right off the bottom and seems to hold it well through the Rev range not that we've really spanked it yet as it's being run in but yes early indications are good.
Build quality is excellent also and with a dedicated billet drop in head, if I'm honest I'd say it's better than the Mugello I'm currently running with the Suzuki piston.

[Storkfoot]

What happened to break the cylinder this time, just grounding the exhaust again?

I too have had this problem whilst abroad and probably wouldn't buy another for the same reason as you. But, I do love the power delivery of the GT186. Have you considered getting it welded again but maybe welding in some support for the flange ?

[Scooterdude]

Im leaning toward the RT195 the more googling I do I have to admit.

Anyone know of any issues that they have had or suffer from?

They had problems with ring peg failure on the RT195 but that issue has now been resolved with the new Meteor cast piston.

[Feersum Injun]

I have a 195 kit that I'm selling to fund a big block build. The barrel and piston are the new 2017 versions and haven't been used, the head is used but is ok. I was thinking of putting it up on the 'for sale' thread. PM me if interested...

[coaster]

Donnie, that does look like its been leaking for some time, maybe not welded properly, caste iron welding is s very specialised process. I was with Storkfoot when his broke and it was an almighty blow, would have ripped the exhaust off if the flange hadn't snapped. It has me worried as I had a brand new GT240 kit on mine and it has the same exhaust stub arrangement I have spoken to Richard Taylor about the issue and he recommends welding in a support if worried about so will be doing just that.

Personally, I don't think there is another kit out there that can hold a candle to the GT kit in terms of usable, reliable power. After we got Pauls welded, the gasket blew and it was running so weak that it would idle at less than about 2k RPM. This was in Italy with temperatures up around 35 - 40 degrees Yet it put up with romping along for hour after hour all the way down to Adria and then back up to southern France where we managed to straighten an exhaust stud bent in the earlier incident. I doubt any other kit would have put up with that, we would have had a holed piston in no time.

[Scooterslag]

............??????

And here is why.

IMG_1310 1 by Donnie Canning, on Flickr

This happened last year when i tapped the top of a speed bump in france, I had it all rewelded but looks like it didnt hold and Ive just run it all in again and got back from france again Sunday.

Enough is enough, Im dumping the kit due to the exhaust port weak design, Ive had enough.

Question is where to go from here.

Easiest thing is to stay small block spacing in which case Im going Imola / RB20 to keep a reed valve or BGM RT195 with no reed valve, is there any Ive missed (not interested in going mugello)

Alternative would be have the casing converted to 200 stud spacing and go for something like an old school honda 205 but im not sure I can be doing with all that running in again frankly.

So, Im going to concentrate first of all on a alloy/nicasil kit that will do a genuine 60mph with possible spurts to 70 with either a clubman style pipe or expansion and a 30mmPHBH carb. On a Series 2 with a 16.5 stone bloke that primarily wants it for touring if that makes sense.

I appeal to you all that have had any of the above kits and would recommend or warn me about possible weaknesses (I was completely unaware of the exhaust port issue on the GT or I would probably have not bothered to be honest.)

What about a old school Suzuki 190 kit? cast, loads of oversizes and can tuned for either fast tourer or out and out racer?

[Donnie]

What happened to break the cylinder this time, just grounding the exhaust again?

I too have had this problem whilst abroad and probably wouldn't buy another for the same reason as you. But, I do love the power delivery of the GT186. Have you considered getting it welded again but maybe welding in some support for the flange ?

nothing, no bumps, had a problem with the clubman pipe coming off the box but didnt see this until I was removing the exhaust stub

It already had support welded in and its obviously not worked, dont get me wrong I love the power delivery of the GT but until the design of the exhaust flange gets sorted like original cylinders theres no way im buying one again.

[Donnie]

Im leaning toward the RT195 the more googling I do I have to admit.

Anyone know of any issues that they have had or suffer from?

They had problems with ring peg failure on the RT195 but that issue has now been resolved with the new Meteor cast piston.

Aye, so i discovered with googles help, which is why im considering it.

[Donnie]

I have a 195 kit that I'm selling to fund a big block build. The barrel and piston are the new 2017 versions and haven't been used, the head is used but is ok. I was thinking of putting it up on the 'for sale' thread. PM me if interested...

as in RT195? how much?

[Donnie]

Donnie, that does look like its been leaking for some time, maybe not welded properly, caste iron welding is s very specialised process. I was with Storkfoot when his broke and it was an almighty blow, would have ripped the exhaust off if the flange hadn't snapped. It has me worried as I had a brand new GT240 kit on mine and it has the same exhaust stub arrangement I have spoken to Richard Taylor about the issue and he recommends welding in a support if worried about so will be doing just that.

Personally, I don't think there is another kit out there that can hold a candle to the GT kit in terms of usable, reliable power. After we got Pauls welded, the gasket blew and it was running so weak that it would idle at less than about 2k RPM. This was in Italy with temperatures up around 35 - 40 degrees Yet it put up with romping along for hour after hour all the way down to Adria and then back up to southern France where we managed to straighten an exhaust stud bent in the earlier incident. I doubt any other kit would have put up with that, we would have had a holed piston in no time.

The oils from the petrol tank / 2 stroke, when i looked at the manifold stub etc up close its not obviously been blowing long at all.

I get all that you are saying but Im sorry, I just don't get the exhaust port issue as in, why it's so fragile? Wasn't Storkfoot running in to Adria so ran rich and would easily explain why he didnt hole a piston etc?

Regardless, once bitten, twice shy. No way Im chancing this again.

[Donnie]

What about a old school Suzuki 190 kit? cast, loads of oversizes and can tuned for either fast tourer or out and out racer?

Got one sat on the shelf, it's cast, old and not common for spares etc so dont really want to use it to be honest.

[Storkfoot]

Donnie, that does look like its been leaking for some time, maybe not welded properly, caste iron welding is s very specialised process. I was with Storkfoot when his broke and it was an almighty blow, would have ripped the exhaust off if the flange hadn't snapped. It has me worried as I had a brand new GT240 kit on mine and it has the same exhaust stub arrangement I have spoken to Richard Taylor about the issue and he recommends welding in a support if worried about so will be doing just that.

Personally, I don't think there is another kit out there that can hold a candle to the GT kit in terms of usable, reliable power. After we got Pauls welded, the gasket blew and it was running so weak that it would idle at less than about 2k RPM. This was in Italy with temperatures up around 35 - 40 degrees Yet it put up with romping along for hour after hour all the way down to Adria and then back up to southern France where we managed to straighten an exhaust stud bent in the earlier incident. I doubt any other kit would have put up with that, we would have had a holed piston in no time.

The oils from the petrol tank / 2 stroke, when i looked at the manifold stub etc up close its not obviously been blowing long at all.

I get all that you are saying but Im sorry, I just don't get the exhaust port issue as in, why it's so fragile? Wasn't Storkfoot running in to Adria so ran rich and would easily explain why he didnt hole a piston etc?

Regardless, once bitten, twice shy. No way Im chancing this again.

No. Carb settings were same before, during and after and definitely not running in. I did have an increasingly large air leak as I hadn't appreciated that the adjacent exhaust stud, to the one that broke off, had bent when I clattered the exhaust ubend.

[Donnie]

ah.

[Covboy]

Hi - I've got a GT 186 and am building a GT240. Please could someone elaborate on what the strengthening weld details are ? A photo would be awesome !
Cheers

Steve

[Storkfoot]

I'd suggest you compare the exhaust flange of a standard barrel with the GT. It is very obvious where it needs support.

[coaster]

If you look at most barrels, the exhaust mounting face rises out of the barrel with vertical sides. On the GT it is like an upside down top hat and the extreme ends of the flange where the studs (brim of the top hat) fit are unsupported and as the sides of the port are only about 3-4mm thick, a hard knock to the manifold is enough to cause it to snap off. My GT barrel suffered accelerated wear on the Adria trip so is currently off the scoot awaiting accurate measurement to determine if it needs a bore. I am thinking of using an old barrel fin to form support bridge on each side. That is likely to be a few weeks away yet though but will definitely post up some pictures when done.

[ULC Soulagent]

What about the Gori Kit Donnie ?