i have to ask for a friend.He want's to put a 250 reedblock in a 175 engine.Does it make sence?Is ther a power profit or a power loose.Any sugesstions?

Chrs:Mike

Duncan, I am very interested in your question because the subject as been discusted with 2 friend that own 175 and I have a few spare parts from a 250A. It surely would'nt be a '' plug and play affair '' and for me ( at least ) bigger carb isn't what I am loocking for for my trial bike, but it's probably only me, I will follow this thread with much interest.

Guy

I dont think it will physically fit?

I dont think it will physically fit?

Lee,I agree with you.But the friend,Heinz you also know him Lee ringed me up yesterday and asked me.It was one of these story's:Hey Mike Mr.xxx told me that in the 70's and early 80's they put the 250 reedblock on the 125/175 and they went like hell.I told him that i was competing at thet time on a 175 and nobody told me that.Anyway,that's why i ask here.So my 175 goes very well with the standart 175 reedblock and I'am pleased with that.

Chrs:Mike

I had a Whitehawk 200 and i fitted a 250 reed block ,you have to machine out the inlet and remove the reed stops(the inside of the barrell will now be the stops)fit a bigger carb (dt 175) is what i used the bike went very well with a wes exhaust as well and electronic ignition. its a lot of work (and money) but it will transform a standard 175. Regards Scorpa250

I have done the same mod on my 175 (190 ish cc) that has a bit of port work plus higher compression, electronic ignition, wes exhaust and lightened flywheel, I used a DT 175 reed block and DT 175 carb so as to keep it all in period, lots of work cutting back the intake to accept bigger reed block, also fitted boyesen reeds, works very well with the higher spec engine but not sure if it would benefit a standard 175.

As anybody tried it on a 175cc motor ?

Guy

If you fit Boyesen reed valves they don't need the original reed stops just a couple of flat bars that replace them, you will probably have to go up two sizes on the pilot jet to a 30. Lot easier then mucking about with a different reed block and it does improve the power.

Hi Mike,

I do have an ongoing discussion with MotoTassinari finding a replacement for 175cc std cage (which as I see it looks like a joke..)My best guess is, if someone riding MX/IT125 ~1975 they must have had the same thoughts..

A set up for TYR will be tested soone(VF is my second improvement step, Jons CR125 cage with Boyesen is step one improvement which working a lot better vs std with Boyesen..)

VF is the way to go..have great experience from KTM SX/EXC 1995-2005..major improvement.

Will keep you updated.

BR,

Edited March 19, 201115 yr by Pat