First Generation Ascots > Tech Section

How To Hop Up The FT500...

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This was a cool read, too bad hardly any of these items still exist

Some of the parts are still available, they are just harder to find. Remember that XR performance parts from the same era will work. There are still high compression pistons in several bore sizes, big bore kits, performance camshafts with needle bearings on the ends, bigger carbs, ThumperStuff header, etc.

Take a look at XR's Only, ThumperStuff & MegaCycleCam Company.

I'd like to raise my compression a point or two, port the head, install a needle bearing cam, larger carb & then see if my Ascot will pull the front wheel like in that first picture.



--- Quote from: WTF304 on January 14, 2015, 09:43:12 pm ---This was a cool read, too bad hardly any of these items still exist

--- End quote ---

Keep your eyes peeled on Ebay and Craigslist, you never know what may pop up. Last year a NOS White Brothers Carb kit showed up on Ebay still in the packaging.

Also most companies when they are done with a production run of something don't just scrap all the plans and technical drawings. White Brothers was absorbed by Vance and Hines so it may be worth trying to make a few phone calls to see if they will jump on it and produce some FT parts again. That's what we kinda had to do with Mark over at ThumperStuff with the headers.

I have built a handful of these over the past 30 years for racing. I will admit that I have never ridden one on the street except with a stock motor. I have developed a pretty straight forward plan for how I build them.
1. I like the Wiseco 12.5:1 piston with the first over. I like the way it revs out compared to the 540 kit. That just seems like the engine is a little lazy to me.

2. The Megacycle 144-21 cam is my choice. You do need to use shortened valve guides, a HD spring kit and have the rocker arm pads hard welded and re-radiused by Megacycle. Really good oil is a must with the 144-21, I like Golden Spectro, I have never had a cam failure with it so I haven't changed brands, but I am sure there are many that will work.

3. I have run a variety of carbs ranging from a 36mm oval bore Keihin, 38 roundslide VM Mikuni, a 36mm flat slide Mikuni and I stuck a big Dell'orto pumper on one once, for some reason. They all worked better than the stock CV. I also like to match the manifolds to the ports and clean up the ports. I have never had a full on professional port job on one.

4. I like the Jemco flat track pipe for HP, but it is loud.

5. I have never tried removing the counterbalancer but I am always checking the adjuster for tension, a broken spring or a cracked tensioner plate. I have seen all those issues, but never had a problem with the counterbalancers or chain.

6. You have to run race gas with the 12.5:1 piston or detonation will cause the piston to brake at the wrist pin. I couldn't even salvage the cases on one engine.

7. You will need to replace the clutch plates and springs more frequently. I think this combination will put about 35 -38 hp at the rear wheel. I have not dynoed this set up but running aagainst other bikes of known HP, that seems like a pretty fair estimate. I think some quality port work, experimentation with jetting, cam timing, ignition timing and pipe swaping could get into the low to mid 40's. I may see on my next motor build since I have a spare head that need valves and guides.

As far as the chassis goes, I highly recommend that you try a set of 1984/85 CB700SC, Nighthawk S, rear shocks. I still see them on e-bay for under $50. Look for the ones in best shape since they are old. I have a set on my current race bike and they are not the weakest link in my suspension set up. They have stiff springs, adjustable damping and are longer so they steepen up the steering head angle for better handling, especially if you go with a CBR 17" wheel. I used to run the CBR600F wheels with a 110-17 front and a 140 -17 rear. I am currently running CBR600F2 wheels with a 120=17 front and a 160-17 rear. It barely clears the chain but it all fits if you switch to a 520 chain.


--- Quote from: ex119x on April 07, 2015, 04:22:53 am ---4. I like the Jemco flat track pipe for HP, but it is loud.

--- End quote ---
Could you please give dimensions and pictures of the Jemco pipe? Perhaps it would be better to reply on the pipes thread, to avoid having to scroll down through this one?
Thanks in advance.


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