Matching Transfer Ports for big bore kit???

I was talking to Chuck, and he mentioned that he had matched, (Making the transfer ports bigger on the crankcase, by using a dremel tool), transfer ports for his magnum with a big bore kit. Is this necessary? I had never heard of anyone doing it until Chuck...

Chris

Re: Matching Transfer Ports for big bore kit???

Well yeah .. people usually do that on racing bikes .. but the thing is.. how far off are they to start with ?

If they are not far off then there won't be a big diff.

And you really have to split the main cases to do a real good job of matching them.

Re: Matching Transfer Ports for big bore kit???

Good question, what difference does it really make?

Re: Matching Transfer Ports for big bore kit???

I did it, and I didn't notice a difference, except the engine intake sounded different.

Re: Matching Transfer Ports for big bore kit???

Matt Wilson /

I've been thinking of doing it to my sachs because the transfer ports on the cylinder are significantly larger than than ones on the crankcase.

Re: Matching Transfer Ports for big bore kit???

MatT I am think of doing the same thing too. I plan on blueprinting the case. Making all the ports line up exactly an polishing the whole intake side. I feel the only problem w/ the sachs engines are they are asthmatic.

Well and I need a new carb and the bigger bing is lot cheaper than the stock. I keep saying this.. if kriedler made a 14hp 50cc engine to set a land speed record than I should be able to get at least 5hp out of the little sachs case.

This winter will be a cuss fest in my basement.

Re: Matching Transfer Ports for big bore kit???

Matt Wilson /

Chuck,

The only bad thing about the sachs engine is that its one piece.... you can't mill the head or space up the cylinder.

It is interesting to note that there is a huge difference between the very small crank case transfers and the large transfers on the cylinder.

I have an extra bing carb for the sachs, complete except without the main jet. If you are interested its $40. I don't have the air filter.

wilsom@rpi.edu

Re: Matching Transfer Ports for big bore kit???

I think a gasket-match would do good for a sachs, but it would be kind of hard to do all the blending, then put it all back together-- What if it dosn't match back up? I'm just not that confident in my skills to try it yet... although I do have a spare case just sittling there...

Re: Matching Transfer Ports for big bore kit???

chuck wrote:

> I keep saying this.. if kriedler made a 14hp

> 50cc engine to set a land speed record than I should be able to get at least 5hp out of the little sachs case.

Yep .. quite true .. always remember .. that the only reason these little mopeds are stuck way down at 2hp is because the government limited them to 2hp.

The modern manufacturers could easily... (easily !!!) .. make them make 5 , 6 , 7 hp .. with great relibility too.

Heck .. they made 50's in the early 70's that had 5hp.

(with reliability).

So all we have to do is find all the obstacles the manufacturers put in place to keep them way down at 2hp.

(I can picture an engineer shaking his head and saying .. "let me get this straight .. you want me to toss out all our standard practices and slow them down on purpose?")

I figure mine is at about 4hp now ...

... and I am also going about it at the dirt cheapest route I can .. by scrounging old parts from old Jap bikes that I know will be better .. then making the rest.

If I wanted to spend money .. I'd get there much quicker.

I still don't want too narrow of a powerband either.

Re: Matching Transfer Ports for big bore kit???

also, you will want to not only "match" the ports.. but smooth them out and polish them correctly. it allows the exhaust / gas to 'flow' better.

thats one of the things im doing to my scoot this weekend.. :)

Re: Matching Transfer Ports for big bore kit???

I dont have the air filter or box for mine. I half assed a lawn mower filter on with some plastic sheet, cork and zip ties. Would have used duct tape but the alcohol fuel melts the glue to fast.

The carb in question... is it the stock12/101/??(83) I think that's th number I forget and I am not getting up unless it is for a beer.

Missing which jet?

Are you missing the main jet(the small one) or the needle jet the larger longer one or both?

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