Modern Vespa

Hi Everyone.

I'm not sure; if you GT owners recall my concern, regarding my PM exhaust loop being too close to the water pump. The excessive heat in the expansion pipe caused discoloration but starting to do a little damage to the housing unit.

After talking to Dave at RV about a heat sink/cooling fin attachment and most recently to Ifixjets at our first OC ride. Ifixjets suggested an exhaust wrap. And after a little R&D, I bought some Thermo-Wrap (graphite-1" x 50') from JEG'S for 29.99 (+shipping). AeroStitch has them too, but in a smaller length.

I did recall my friends using "wraps" on their quarter-mile/SCCA racing Hondas but, never thought about applying it to my situation.

I used the 1" width, because I was wrapping the material in a confined space and it was a little tricky. Especially, trying to keep the wrap snug and consistant moving around the loop. Plus, I didn't remove the exhaust from the engine. It would have been easier, if I had unbolted the exhaust... I did use the entire length wrap.

I started and secured the start (and end) with ordinary hose clamps. I also wore disposeable plastic gloves and a disposeable respirator during my mod. I was not really sure what the material was made of and there was no warning label regarding dangerous or hazadous materials (there's none but wore them as a pre-caution anyway).

Here's what they claim-
"Looking for a way to make more horsepower? We know the answer is yes, and Thermo-Tec lets you keep the power you have been losing, plus reduces underhood temps up to 70%! By keeping the exhaust gases from cooling, the exhaust gas velocity can remain high, thus improving the scavenging effect. And for every 10-degree decrease in air intake temp, expect horsepower gains of 2% with turbo chargers and 1% with carburetors."

I noticed very little power change but did notice the engine seemed to settle down at 50-65 mph (my cruising speed) after it has warmed up. And it WORKS!!! No more discoloration/heat damage.

Face Mechanic thought it was a great idea. Much Mahalos (Thanks!) to Ifixjets for the most excellent suggestion!

Oh BTW, after the first couple of miles/hours of riding, the exhaust wrap will smoke like crazy! My brother, Harold who was following me thought Ms. Marley was gonna catch on fire. I also freaked-out a bunch of cagers at the stoplight with all the smoke.

If any one else has an existing PM exhaust on a GT200L or considering it, you might want to consider this wrap. It's relatively inexpensive in the long run and could save you a trip to the dealer/repair shop.

If anyone has any questions regarding this mod, please ask!

Aloha, Will


Notice previous heat damage to the bottom of the water pump.

Very good solution. It looks good also, thanks for the idea, Beale.

Hello Will, I am glad that stuff worked for you. When I was working in SF at SFO, a co-worker asked me to help with some race car prep ( Formula Fords ) and they used that type of wrap on the exhaust systems. I may even try some on my stock exhaust.

So how is the wrap job holding up? Any problems with the pipe getting too hot or other damage due to the wrap? Does the loop in the pipe still have a chance to cool down?

It's good idea.....

If pm68 pipe have this question that on gt200

Did R'Idyllwild today 100+ miles. It was a really warm day.

Dave (Vespa Riverside) to a look at it up in Idyllwid. The wrap in still intact and doing its job. Containing heat within the pipe itself and not damaging other vital parts.

Yes. The pipe does have a chance to cool down via ambient temp.

PS. My GT has been my daily driver for the past couple of months with no problems.