If you are just riding AHRMA the bike should already be good to go. The NATC vintage class or ITSA vintage trials is a whole animal of another color. For riding modern events it needs to be geared down considerably. Good brakes and suspension is worth way more than frame mods.

Agree on the gearing. 1976 Mod 183. I went down 1 tooth on the front to 11 (a 10 is too small) and up to a 52 (from 46)  in the rear for an 18.9% reduction. Made a significant difference. I had to modify the lock washer on the front sprocket as the original was too large and didn't allow the chain to seat correctly.

 

Ratio Calculator:

 

www.sprocketcalculator.com

I'm probably looking right past it, but I don't see that thread. Do you have a link?

page 2 in topics about tenth or so in the list.

Agree on the gearing. 1976 Mod 183. I went down 1 tooth on the front to 11 (a 10 is too small) and up to a 52 (from 46)  in the rear for an 18.9% reduction. Made a significant difference. I had to modify the lock washer on the front sprocket as the original was too large and didn't allow the chain to seat correctly.

 

Ratio Calculator:

 

www.sprocketcalculator.com

 

I don't know what gearing your bike was on when you got it but standard gearing was 11 : 46 for a 520 chain

I'm probably looking right past it, but I don't see that thread. Do you have a link?

Here are few link on foot peg mods that might help

http://www.trialscentral.com/forums/topic/55487-what-did-you-do-to-your-bultaco-today/?p=426679

http://www.trialscentral.com/forums/topic/55487-what-did-you-do-to-your-bultaco-today/?p=427038

http://www.trialscentral.com/forums/topic/55487-what-did-you-do-to-your-bultaco-today/?p=427196

http://www.trialscentral.com/forums/topic/55487-what-did-you-do-to-your-bultaco-today/?p=428685

Or find a Fantic .... , just kidding , couldn't resist

The 199A is an excellent bike, I have recently been fixing mine to have a more modern feel.  The few items that gave me the most improvement was to move the foot pegs back and down about 1/1/2 inches, I have also installed the OZO adjustable rear shocks which are simply amazing that are sold thru Inmotion.  The best performance mods Ive found is to switch from the 350 flywheel to a 250 flywheel, it still has the tractor like pull and the zip of a modernish bike.  Ive also switched to a flat slide OKO carb that works very well.  I have also repacked my mid muffler and reworked the silencer to a Team Puma mod, which is basically cutting the muffler open removing the mouse trap design on one side, replacing it perforated steel and packing, then removing the twin tip exhaust and replacing it with one one inch diameter outlet...the muffler mod is also a must.

I have also switched out the complete front end with one from a 2004 Sherco including triple clamps which changes the rake alot and makes it turn more like a modern.    If anyone is interested in my mods I'd be glad to email pictures, especially the muffler which seems to be a secret. Items in the future to test is fiber clutch plates and electronic ignition.

I really enjoy riding mine, almost more than riding modern bikes anymore. Im also using s3 triple clamps and fat bars.

     In the final picture shows some of my muffler mods, I removed the mouse trap, replaced it with perforated steel and packing, on the outside Ive removed the twin tips and replaced it with one 1 inch dia tip,  the exhaust is a huge improvement to crisp throttle response.

Edited September 9, 20169 yr by shercosteve

Or find a Fantic .... , just kidding , couldn't resist

 

And then we would have an even bigger list of all the mods required to turn it into something decent....................I mean a Bultaco. Also could not resist  

 

Stuart

 

The 199A is an excellent bike, I have recently been fixing mine to have a more modern feel.  The few items that gave me the most improvement was to move the foot pegs back and down about 1/1/2 inches, I have also installed the OZO adjustable rear shocks which are simply amazing that are sold thru Inmotion.  The best performance mods Ive found is to switch from the 350 flywheel to a 250 flywheel, it still has the tractor like pull and the zip of a modernish bike.  Ive also switched to a flat slide OKO carb that works very well.  I have also repacked my mid muffler and reworked the silencer to a Team Puma mod, which is basically cutting the muffler open removing the mouse trap design on one side, replacing it perforated steel and packing, then removing the twin tip exhaust and replacing it with one one inch diameter outlet...the muffler mod is also a must.

I have also switched out the complete front end with one from a 2004 Sherco including triple clamps which changes the rake alot and makes it turn more like a modern.    If anyone is interested in my mods I'd be glad to email pictures, especially the muffler which seems to be a secret. Items in the future to test is fiber clutch plates and electronic ignition.

I really enjoy riding mine, almost more than riding modern bikes anymore. Im also using s3 triple clamps and fat bars.

IMG_2590.JPGIMG_2591.JPG     In the final picture shows some of my muffler mods, I removed the mouse trap, replaced it with perforated steel and packing, on the outside Ive removed the twin tips and replaced it with one 1 inch dia tip,  the exhaust is a huge improvement to crisp throttle response.

Now that I like !

What model flat slide OKO did you put on your 199A?

Shercosteve, think your inbox is full. Couldn't pm you.

Mark,

 

My OKO is a 26 MM   it came from Mid Atlantic Trials , here in the US.  He sets them up jetted and ready to use, plus included is all boots for the Intake and airbox.

 

 

The 199A is an excellent bike, I have recently been fixing mine to have a more modern feel.  The few items that gave me the most improvement was to move the foot pegs back and down about 1/1/2 inches, I have also installed the OZO adjustable rear shocks which are simply amazing that are sold thru Inmotion.  The best performance mods Ive found is to switch from the 350 flywheel to a 250 flywheel, it still has the tractor like pull and the zip of a modernish bike.  Ive also switched to a flat slide OKO carb that works very well.  I have also repacked my mid muffler and reworked the silencer to a Team Puma mod, which is basically cutting the muffler open removing the mouse trap design on one side, replacing it perforated steel and packing, then removing the twin tip exhaust and replacing it with one one inch diameter outlet...the muffler mod is also a must.

I have also switched out the complete front end with one from a 2004 Sherco including triple clamps which changes the rake alot and makes it turn more like a modern.    If anyone is interested in my mods I'd be glad to email pictures, especially the muffler which seems to be a secret. Items in the future to test is fiber clutch plates and electronic ignition.

I really enjoy riding mine, almost more than riding modern bikes anymore. Im also using s3 triple clamps and fat bars.

IMG_2590.JPGIMG_2591.JPG     In the final picture shows some of my muffler mods, I removed the mouse trap, replaced it with perforated steel and packing, on the outside Ive removed the twin tips and replaced it with one 1 inch dia tip,  the exhaust is a huge improvement to crisp throttle response.

 

 Did you change the ignition flywheel, or the right side flywheel?

I would think the clutch side flywheel/counter balance. The 250 ones are about half the weight = less rotating mass means should rev quicker.

Ignition side is a lot easier to change and makes a difference  -  whether you need to is personal preference though as there's not much wrong with the pick up of a 325 Bultaco motor, especially for classic trial sections