250cc 4 valve Grom Clone

[Thumper]

That is one seriously musclebound Grom clone.

It looks gnarly, probably rides that way too

Nice

[warrenpeas]

Originally Posted by Thumper

That is one seriously musclebound Grom clone.

It looks gnarly, probably rides that way too

Nice

im having difficulty getting it tuned. first i tried a 28mm PE carb i think is too small and my wideband gauge was telling me the main jet needed to be 100 or 105 which i cant understand at all so today i put on the 32mm pwk and im getting closer with a 130 main jet

[delzy]

Originally Posted by warrenpeas

im having difficulty getting it tuned. first i tried a 28mm PE carb i think is too small and my wideband gauge was telling me the main jet needed to be 100 or 105 which i cant understand at all so today i put on the 32mm pwk and im getting closer with a 130 main jet

I think when you go down on carb size, you also have to go down on jet size because the smaller throat and higher flow results in a much more powerful venturi. I'm planning on using my pz27 on it. I would love the wide band. It is telling you you're rich when it said to bring the jet size smaller.

This makes sense when you think about it because the airflow is increasing while the throat isn't so you get a bigger change in pressure. Now I need an oil cooler. I ordered a 30 tooth 520 JT rear sprocket for a grom that I hope will work. I don't think there is room for a 16 or 17 up front. I'm also going to get creative to get that intake right.