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Trs one rr 250 high compression head


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10 hours ago, singesavant said:

How is the bottom end performance with the S3 hi-comp head insert? Does it want to stall easier? (pro's con's?) I already purchased a S3 hi-comp insert for more power, but did not install yet because it took a long time to find the correct jetting on the Keihin carb with the new Boyesen Pro reeds. The TRS 250 had a rough burble between 1/4 to 1/2 throttle when the main jet started to come into play. Had TRS motorcycles since 2017 and this one (2021 250) is the smoothest running one i've owned, next to the 2019 TRS Gold 250.

2021 TRS 250 RR (Boyesen Pro reeds)



Do you find the S3 high compression head to benefit 

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49 minutes ago, trials01 said:


Do you find the S3 high compression head to benefit 

Alright To be fair, I brought a 300 which I downsized to 250 top end. The top end I bought was a second hand from a Spaniard whom did the opposite change from 250 to 300cc.

I got it with both standard and high comp s3 head. When I received it I rushed to instal it and went direct to the s3 high comp for which I measured comp ratio (which I did for both heads)...

So I can not tell you what the diff between both, I am sorry!

On a side note believe it or not the s3 head and hence head cover (trs not compatible) are from gasgas txt and do fit my trs...



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