Swiss Hutless Rondo Build

[NewbCarter]

We aren't going anywhere

Wasnt sure if anyone was following still , but

 

[NewbCarter]

I find it ironic that i can get an old 30+ year old moto-cultivator to run like new , and a puny go kart engine is kicking my rear ....
https://www.youtube.com/watch?v=_jVcyspqHXU

Slightly off topic , but just to prove i do have a bit of knowledge

 

[NewbCarter]

Progress .. or regress ?

Welded on the EGT probe , not the best of welds but it does the trick .

And after so much hassle , i went ahead and machined my own rotor puller .

Rotor went off , and so did my happy face . Crankshaft and key are ok , keyway in rotor is fubar.

 

[NewbCarter]

So far , dead end unless i can find the rotor ... which so far isnt proving to be "search and click buy"

Any ideas / advice if repairing this rotor is possible ?

 

[anderkart]

Both of these online shops offer international shipping:
https://www.marmaxkartsandparts.com/product-page/yamaha-kt100-s-rc100-s-ignition-rotor
http://www.out2win.com/catalog/yamign.html

 

[NewbCarter]

Thats the issue .. those dont have a cutaway for the starter ring .. and im not sure how would they react to machining

 

[NewbCarter]

Well , got some time tomorrow , il try to do a proper job documenting it all.

Tearing the engine open (again) , and do the whole checkup (again) from the bottom up .

*sigh*

 

[NewbCarter]

Pics.

 

[Desertduler]

I would chamfer the cylinder liner leading into the transfer ports and taper the leading edge of the transfer port dividers.

 

[NewbCarter]

By chamfer you mean , rounding the liner towards the transfer port openings ?

 

[Desertduler]

By chamfer you mean , rounding the liner towards the rransfer port openings ?

Correct.

---------- Post added at 11:52 AM ---------- Previous post was at 11:46 AM ----------

You can use round file to radius and chamfer the liner and the dividers that it how I do it and it is easy to blend the transition in those areas.

 

[Desertduler]

Look at the difference of the transfer port dividers and the cylinder liner where it transitions into the transfer ports.

 

[NewbCarter]

Probably will do that when i get time ...

In the meantime , i have found some interesting stuff
1) My head gasket is 0,4mm , and my cylinder base gasket is 0,7mm . I have not found (online) either one that match what i have . Either the head gasket is alot thicker ( copper , 1mm) or the cylinder base gasket is alot thinner ( 0,45mm) ..

2) I will need new crankcase seals .
3) There is a small chance i have found a PVL module that could fit my engine , for a low price .

 

[NewbCarter]

Exhaust touchup

 

[NewbCarter]

Shiny.

 

[NewbCarter]

 

[NewbCarter]

Sorry for no updates , college is killing me.
Luckily i got some time in today , and took measurement oof the crankcase seals , and clutch seals.

The crankcase bearings are ok , the clutch bearing is ok but the copper bushing in the clutch could use some care . Probably be best to replace it .

 

[NewbCarter]

Welp , finally got around to working on the Rondo again , but i brought in a extra pair of hands .

To shorten it up :
-KT100 yamaha is gone
-Hello TG14 Parilla
-Hello complete 25mm axle
-Hello new vega semi-soft slicks

Link : https://www.youtube.com/watch?v=rNgSkvMaeFo
And a pic of the fully checked and assmebled engine

 

[NewbCarter]

Checking the timing of the ports in the engine ( duration ) .

Cleaned up the piston and the cylinder head . 48,3mm on the piston , which gives around 91,6cc , so plenty of life left .

 

[NewbCarter]

Welp , playing around with the software that mr. Desertduler reccomended , and i keep getting ( to my knowledge ) weird results .

The stock exhaust is somewhere around 60-75cm long and is the "stock" exhaust where this engine is supposed to be used ( Formula 100 classes , Pre 90s , etc ).

I double checked the port timings , and all the measurements , and for a peak HP of 25 @ 18000 RPM , i get an exhaust that is very short ( 455-497mm ) with a stage three diffuser , tuned for as wide of a powerband one could get .

Im pretty sure im doing something wrong . Port durations are as follows :
Intake : 140 degrees
Exhaust : 165 degrees
Primary transfer ports : 128 degrees
Boost port : 125 degrees