Block Machine Work

[delray]

Assuming this is a newer style camTony,better find out if dynocams can weld that kind of steel and need to find out if they can grind it with the same base circle as the compression relief cam has. If they grind it small like the vintage cams the compression relief arm/shaft will not aline correct to the lifter.
I mentioned earlier about how i had to adjust my measurements so the arm/shaft would aline correct.

Goodluck i hope it works out...:thumbsup:

 

[fasttony]

Delray

The cam I sent in is an older cam I machined for mechanical comp relief I believe it's the same material as a 70's cam.

Tony

 

[delray]

Ok good,i hope thats works too...:thumbsup:
I do have that style too. Kind of curious where that pin/shaft go's
Though the lobe. I will have to take a look at mine sometime.

 

[fasttony]

Delray

It looks like I have the orientation off for the compression relief by 90 degrees, I may have taken info from a H35 cam with intake and exhaust reversed. When the cam comes in I will weld the heel of the exhaust lobe then CNC cut a bump comp relief and go with that for this summer, next winter I will modify the 245 cam I am currently running with the mechanical parts

Tony

 

[fasttony]

Much Better! I took the Rupp out for a ride today what a difference the new HS50 and setup makes, quicker acceleration, better top speed, less vibration and the iron cylinder has very little blow by, I now have faith these little Tecumseh engines can get the job done. I do have to redo the engine isolation mount, the rubber compound I bought from MaMaster Carr is junk so I will try silicone rubber, the toggle clamp hold down from HF split the rubber end so a larger diameter rubber stop pad is needed, I will get the Dellorto carb working right. Rupp is going to be a blast to ride on July vacation!

Tony

 

[delray]

What no pic's or video. Glad you got it running.
I'm totally impress with my 245 dyno cam. Perfect cam for a hs-40 or 50
Tony is your flywheel aluminum or cast steel? And now that you got it running with a good carb have you tried
To advance the timing yet? I have mine set at 30 degrees advance and pulls hard up to 5700 with a slightly modified stock carb.
I think if you get that 19mm carb working right that engine should run strong with more timing and gearing.
What's with the rubber mount? Can you run with out it?

 

[fasttony]

Delray
I could try taking a video but since it's just me riding it could get scary and end with curse words, when Rupp is up to full speed I will get a picture of the speedometer and post. I am not sure if fixed position timing of more than stock .035" would benefit an engine that can be driven at lower engine speeds, I was running .055" advance with the aluminum cylinder HS50 and noticed is sounded rattly driving at mid range RPM under a light load, it's my understanding unleaded fuel burns faster than leaded, more timing might not help overall driving. The only way to know for sure would be to tune it on a Dyno, that would be fun if someone had one around here. The engine isolation plate was removed this afternoon and cleaned up going to try black high heat silicone rubber, if that doesn't work I have some 1" thick aluminum to replace it. The weather in Maine this weekend isn't going to be very good hoping to have the mount done by Sunday, the 19mm carb will also get some attention. A good part of the better acceleration is from going back to the larger Rupp rear sprocket, I am thrilled this bike has the potential to cruise at higher speeds, after driving it only 200 miles the last two years I am hoping to ride the wheels off it this year.

A big thanks to the guy's here that build their engines beyond stock and all those who have offered advice, I didn't know companies like DynoCams existed their parts make a difference.

Tony

 

[delray]

Cool....:thumbsup:
Get the 19mm figured out. I think it will be strong.
They seem to be better over a stock carb. At less the one black widow i road in the pass.....

 

[tecumseh power]

Advancing the timing with that cam should give you more power even in the mid range. I would definitely try it. My 245 cammed engine has power everywhere at 30 degrees. I do run premium fuel in it, but it's an OHH 195cc engine with a 172cc head shaved .040", so it has a lot of compression.

 

[markus]

Much Better! I took the Rupp out for a ride today what a difference the new HS50 and setup makes, quicker acceleration, better top speed, less vibration and the iron cylinder has very little blow by, I now have faith these little Tecumseh engines can get the job done. I do have to redo the engine isolation mount, the rubber compound I bought from MaMaster Carr is junk so I will try silicone rubber, the toggle clamp hold down from HF split the rubber end so a larger diameter rubber stop pad is needed, I will get the Dellorto carb working right. Rupp is going to be a blast to ride on July vacation!

Tony

Sweet :thumbsup: Ive had the Dell on an HS40 roadster2 and the driveablilty of the slide valve is so nice-so much more throttle to work with over the standard carbs and very smooth too. I was very surprised, it made the bike feel much more roadworthy, which looks like is what you are after! I would not know how to tune it for your modified application but hopefully you get it figured out.

 

[fasttony]

Update
Last week I planned to take Rupp out for a spin and learned I still had engine issues, it would not start only spit and sputter just like before, I tried Ether no go it had a weak spark again. After just about pulling the rope out of it I changed to a new spark plug and it started but was skipping at idle then all of a sudden it came out of it? I took it for a ride and not far down the road the throttle linkage came part way off from the governor shaft then it was pushing oil out the breather seemed like it had the plague. Today I checked spark it was weak so I swapped the coil and condenser back to Tec parts it now has a very good spark. I lowered the oil level and replaced the valve cover gasket then put a micro weld bead on the governor shaft end hopefully the plague is fixed. The last issue to get squared away is the custom engine mount I tried several different silicone rubber compounds recently it's still too stiff, it seems the silicone manufacturers vary all over the shore scale I am waiting for another batch of softer silicone rubber mix to come in, below are pictures of the current mount. One of these days this is going get better.

Tony

 

[fasttony]

Final Update

Yesterday I took the Rupp out for a couple of mile ride speed was good I still had some oil blowing out the crankcase/valve cover vent and vibration issue was a little better. I changed the valve cover to the type with a rubber hose to see if that would stop the oil from blowing out. I planned on riding all day today got out early and quickly found the same ignition problem as before, sputtering at idle and cannot open the throttle without stalling, I checked spark it's now weak for some reason this has been an intermittent issue with my Tec engines the last couple of years. I let the bike idle for about 10 minutes and it came out of it just like before so out for couple of mile ride, when I got back I still had some oil blowing out the breather, the oil level is where it's always been so the only thing I can think of is the ARC rod splashes the oil around more or higher RPM's are causing the oil to blow out maybe both? I decided today to park the Rupp's for awhile, I drained out the gas changed the oil and put them away. I am looking into applying for a motorcycle license and possibly buying a little older Honda Rebel, the last few years my wife has been uncomfortable with the Rupp hand brakes, the Rebel will get us out on the road together with enough power to keep up. I would like thank everyone here from those who run this site to the good members who offered advice, I will still be around I just need to get some road time before summer is over, I wish everyone here many happy RPM's with your small engines.

Thanks

Tony