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GT186 versus GT200

PostPosted: Tue Dec 31, 2019 6:51 pm
by Storkfoot
Has anyone any real life road experience of riding Lammies with both these kits fitted and in similar set ups please?

If so, what difference did you discover please?

I am well used to the 186 but never ridden the 200. I am planning a fairly standard engine to use for UK rallies. Highly likely I’ll use a standard exhaust and a Mikuni TM24.

Re: GT186 versus GT200

PostPosted: Tue Dec 31, 2019 8:27 pm
by coaster
Mr Gummage has both but with different setups, 186 has an expansion and 200 has a clubman I believe

Re: GT186 versus GT200

PostPosted: Wed Jan 01, 2020 8:06 pm
by Leotech
I've a GT200 kit in a s2 Lamby, BGM pipe and 30 PHBH carb

It's reasonable and reliable. Not going to set the world on fire speed wise. 67 mph flat out but will sit at 60 all day. Sat Nav speeds so genuine.

It might fare better with a better pipe but for what I use it for it great.

Had it on a dyne other day makes 18 bhp and its very linear power. It's not a very exciting ride and it needed reboring after about 5000 miles as it was piston slapping quite badly. I put a better quality (Wossner) piston in it this time so hopefully ill get more miles.

I'd post the graph but can't do it on here.


My friends a GT185 and has just put a 52 AF big bore on it with the 30mm stinger, it seems to have transformed it regarding acceleration, we have yet to try how it goes long term though. Maybe that pipe would benefit the 200 too.

Re: GT186 versus GT200

PostPosted: Wed Jan 01, 2020 9:44 pm
by Storkfoot
Leotech wrote:I've a GT200 kit in a s2 Lamby, BGM pipe and 30 PHBH carb

It's reasonable and reliable. Not going to set the world on fire speed wise. 67 mph flat out but will sit at 60 all day. Sat Nav speeds so genuine.

It might fare better with a better pipe but for what I use it for it great.

Had it on a dyne other day makes 18 bhp and its very linear power. It's not a very exciting ride and it needed reboring after about 5000 miles as it was piston slapping quite badly. I put a better quality (Wossner) piston in it this time so hopefully ill get more miles.

I'd post the graph but can't do it on here.


My friends a GT185 and has just put a 52 AF big bore on it with the 30mm stinger, it seems to have transformed it regarding acceleration, we have yet to try how it goes long term though. Maybe that pipe would benefit the 200 too.


Sounds similar to my GT186 with same carb and pipe. From memory, mine was just shy of 17 on the Dyno and has been GPS at over 70 when not wide open throttle.

I want to try this engine with a standard exhaust to keep it quiet, yet torquey.

Do you run the carb open? Surprised it needed a reborn after 5000.

Re: GT186 versus GT200

PostPosted: Thu Jan 02, 2020 12:43 am
by Simon_T
what's your jetting on these motors please

Re: GT186 versus GT200

PostPosted: Fri Jan 03, 2020 10:25 am
by burnside
coaster wrote:Mr Gummage has both but with different setups, 186 has an expansion and 200 has a clubman I believe


Mr Gummage? :lol:

I do have both, GT186 with Fran Race and GT200 with BGM Clubman, both with PHBH30. The obvious difference is down to the pipes, the Fran race is more revvy with a very noticeable power band whilst the BGM has more low down torque and has a smoother power delivery, but is no slouch. The 200 kit pulls 4.6 gearing and is a really nice ride, loads of torque and I've sat at 70 in favourable conditions for long stretches. I can't fault the 186 at all but the 200 is an upgrade...but if going large block then there's also the 240 to consider?

Re: GT186 versus GT200

PostPosted: Fri Jan 03, 2020 5:29 pm
by Storkfoot
burnside wrote:
coaster wrote:Mr Gummage has both but with different setups, 186 has an expansion and 200 has a clubman I believe


Mr Gummage? :lol:

I do have both, GT186 with Fran Race and GT200 with BGM Clubman, both with PHBH30. The obvious difference is down to the pipes, the Fran race is more revvy with a very noticeable power band whilst the BGM has more low down torque and has a smoother power delivery, but is no slouch. The 200 kit pulls 4.6 gearing and is a really nice ride, loads of torque and I've sat at 70 in favourable conditions for long stretches. I can't fault the 186 at all but the 200 is an upgrade...but if going large block then there's also the 240 to consider?


Thanks for that. I have no wish to go to 240 on this engine. I am interested that you feel that the 200 is more torquey. This may swing the balance in favour of the 200.

Re: GT186 versus GT200

PostPosted: Fri Jan 03, 2020 6:13 pm
by vegansydney
Storkfoot wrote:I want to try this engine with a standard exhaust to keep it quiet, yet torquey.


I'm in the final stages of a GT186 build with a TM24 and have opted for an RS Clubman, but after re-reading the conclusions of the Clubman dyno shoot out in Scootering (all done on GT186 engine), I'm tempted to try a standard GP/dl exhaust, particularly as most of my riding is in New York City traffic.

Scootering/Darrell Taylor wrote: ...my No. 1 being the standard exhaust! Not one aftermarket pipe matched the power up to 5000rpm...

Re: GT186 versus GT200

PostPosted: Fri Jan 03, 2020 9:04 pm
by Storkfoot
I’d missed that but it’s very interesting that it is right the way up to 5000 revs :o

I have seen a post recently saying there may be an issue with the TM24 not being an easy fit with the GT manifold but I am willing to give that a go as it is such a responsive little carb, even if the manifold needs cutting and welding.

Re: GT186 versus GT200

PostPosted: Sat Jan 04, 2020 11:29 am
by coaster
burnside wrote:Mr Gummage? :lol:


Oops, sorry Ross :oops: How's Una Stubbs these days :lol:

Re: GT186 versus GT200

PostPosted: Sat Jan 04, 2020 6:36 pm
by burnside
coaster wrote:
burnside wrote:Mr Gummage? :lol:


Oops, sorry Ross :oops: How's Una Stubbs these days :lol:


Had a slice of cake and a cup of tea with her just last week :lol:

Re: GT186 versus GT200

PostPosted: Sun Jan 05, 2020 11:15 pm
by vegansydney
Storkfoot wrote: I have seen a post recently saying there may be an issue with the TM24 not being an easy fit with the GT manifold but I am willing to give that a go as it is such a responsive little carb, even if the manifold needs cutting and welding.


I posted about that issue here and on the 'other channel'. Mike from On The Lam in California sent me several pictures of how he cut and re-welded the manifold to fit the TM24. Unfortunately due to various obligations over the holiday period, I've not had a chance to get the engine in the frame to measure it out yet, but will post pictures when I do.

Re: GT186 versus GT200

PostPosted: Mon Jan 06, 2020 7:38 am
by Storkfoot
Thanks very much.

Re: GT186 versus GT200

PostPosted: Mon Jan 06, 2020 10:53 am
by coaster
I' have both left and right hand GT manifolds so will bolt both on later, measure clearance to the silent block and report back. Unfortunately I dont have a mikuni and mine is a 200 but it might help

Re: GT186 versus GT200

PostPosted: Mon Jan 06, 2020 11:24 am
by Storkfoot
coaster wrote:I' have both left and right hand GT manifolds so will bolt both on later, measure clearance to the silent block and report back. Unfortunately I dont have a mikuni and mine is a 200 but it might help


From what I understand, Col, it is specifically an issue with the TM24 and the other generally used PHBL and PHBH carbs are fine. I have had loads of clearance of PHBHs on both manifolds in the past. It may be because the TM24 is quite small and flat.