Thunderslide woes...

[Peter_nikols]

Hello everyone,
Happy New Year....

Took apart the Buell Thunderstorm engine on my recently purchased 1998 S1
and I noticed the carb had a Dynojet Thunderslide. I was very ammused since I always wanted to put one of those on my 2003 Sportster. I was thinking I would swap carbs since I'm getting a new carb setup for the Buell.

Once the heads were off we noticed a lot of carbonation. My mechanic took the heads apart and the pistons out and was quite shocked considering the motor only had about 18000 miles on it (so the odometer says). The valves were coated with carbon as well. He said it was running way too rich and said the carb was the problem. He really doesn't like the Thunderslide and suggests I don't use it on my Sporty.

I have heard good things about them in the past. I couldn't really tell any problem with it. The bike was super responsive, ran great and didn't pop like my Sportster does.

Has anyone had any problems with these Thunderslides?

Thanks

[Edster]

Howdy,
I was runnin a thunderslide for a bit 'til I switched to a Mikuni. I honestly believe the stock slide is fine. I think that the plastic slide is just a gimmick. I think the company was tryin to emulate the edge of a flatslide carb. The big difference the thunder side kit makes is the accelerator pump nozzle w/ the little ball check (more volume and the extra volume stays in the pump nozzle area vice drainin back to the bowl.) and the emulsifier tube(fewer holes means a richer mixture pulled through when you open the throttle ater the accelerator pump shot.) The jets and the needle supossdly compensate for the rich conditon that the tube and acc. pump provide At least thats what I think seems to make it work just by lookin at it as I haven't acces to test equipment and lookin at your plugs really only tell ya what your doin at full throttle (imo) What kind of breather set up do ya have. I know that the factory type used on Sportsters doesn't lend itself in helpin w/ carbon build up. I would look at where your clip is positioned on your needle. I'm willin to bet your mid range is a little too fat(thats where ya spend most your time anyway) Ther are a few guys who use a stock carb but just the needle and main jets from the thunderjet/slide kit or a mix or match there of. I hope this helps. Also try using the search function on the boards.

[4camSam]

Edster is right about the Mikuni. My experience has been this: I have a '05 XL1200C. Use the Thunderslide kit for the Twin Cam (pn 29605-00A). Go a little bigger on the slow jet and a little leaner on the needle setting from what the instruction sheet says. On the dyno my bike did 71hp and 74tq with a Twin Cam air cleaner and the baffles cut out of the stock mufflers. This engine is stock in all other ways. The main thrill is cruising around at part throttle and just WHACKING it open...HANG ON!!! As far as over fueling, no problems so far, but tuning is a process to learn...every engine is slightly different. Talking to guys at the track, though, I think the Mikuni will blow my mind even more. Good luck with yours and stay tuned for pix of my cool a/c setup.