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  • justbigreds

New Seat Foam for Honda 250ES BIG RED

Updated: Dec 1, 2022

After many disappointing searches for 250ES seat foam I decided I was going to have to take this on by myself. My upholstery skills are very limited but I am always up for learning new skills and improving existing ones. Note this is an ongoing project and I will do the next seat differently and post updates.

Finding the foam - Seat foam is not all the same - foam has different densities. I ended up buying my foam on line from the foam factory ( I used the 3" thick supermax foam based on their recommendation. Note 3" is the thickest supermax foam offered. For the next seat I will use 4" Supermax foam by gluing the 3" inch Supermax thick and 1" thick Supermax foam together. ( I did this and it worked out great -here's the link 250ES Overstuffed seat foam replacement ) This Supermax foam feels like motorcycle/ATV seat foam. I have some foam from a craft store that is furniture foam and it is soft. I found it difficult to find dense foam like the Supermax foam. I do not know the density of the original 250ES BIG RED seat foam when it was new.

The original seat foam was in pretty bad shape but it was good enough to use as a template.

Picture of the original seat foam

I used some drawer liner to make some templates of the original seat foam. The templates will be used to guide the cutting of the new foam.

I made the templates a little larger than the original as I cannot cut the foam very accurately. I will shape/trim the foam after the initial cuts.

The top of the seat pan is used to make a template for the bottom of the seat foam.

The bottom of the seat foam is not just flat. It has cutouts to fit the seat pan. This could be a reason why no aftermarket seat foam is available.

I used a dial caliper to measure the depth of the indentations in the bottom of the original seat foam. Note I found that the razor blade worked better than serrated knife shown in the picture.

Put the template on the foam and traced it with a marker.

Used a razor blade to cut the foam.

Glued the seat foam to the seat pan.

Here is the spray adhesive I used to attach the foam to the seat pan. It worked well.

Used a razor blade and with looking at the original foam did some rough trimming.

Used a marker and the original seat foam to create a cardboard template to help guide the trimming of the new foam.

Using the cardboard template to trace out the new foam for trimming.

I found that I could not cut/shape the foam accurately with a razor blade. I ended up using a grinder with a flapper wheel to shape the foam. This worked very well however it made a big mess. I would recommend doing this outside with a mask and coveralls on. Note the chunk on the back was due to a cut that went too deep. I glued a piece on to it and then "ground" it down using the flapper wheel - it worked out well.

Close up of foam after it was shaped with the flapper wheel.

Foam after being shaped by the flapper wheel.

Next step was to put some poly fill/ quilt batting on the foam. This helps hide any small imperfections in the seat foam. This can be purchased at or a craft store. The poly fill is attached to the foam using the spray adhesive.

Used a razor blade to trim the excess poly fill.

Next I put a garbage bag over the poly fill using the spray adhesive. I like doing this as it should protect the foam better from moisture and make installing the seat cover easier.

Here is the finished product. I am happy with the results. The new foam feels great as compared to original foam. I used a pit replica seat cover that worked out great. This seat cover has no seams showing on the top like the original seat cover. This seat cover was more difficult to install especially in the corners. I did not provide the seat cover installation information in this post. If you are interested a link for seat cover installation is provided below.

627 views5 comments


Mar 18, 2023

Thank you for those suggestions. I have no idea how much is missing, so hopefully I can find information/pictures to go by. Thanks again!


Mar 08, 2023

What overall size replacement foam did you order?

Mar 18, 2023
Replying to

I don’t have a lot of experience with this situation. You may want to cut the foam as if the seat pan is complete. Then you could put the cover on and fasten it temporarily with some clamps to see how it looks. Note the cover may not have enough material to allow for stapling the cover to the pan.

If you need to repair the pan fiberglass would work or you could plastic weld or epoxy some plastic pieces in to restore the seat pan shape.

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