Hot Rod HS40-Powered Full Suspension Cat 250

#62
Pat [MENTION=31471]mrpat[/MENTION] bent me up some bars, custom to my request, and created a 3/16 base plate per Cat dual shock specs. I can't say enough about his skills, or willingness to take this on- and then wanted only shipping for it- and it was his metal. I don't want to embarrass the man, but he's helped me out several times over the years. Thank you Pat.

I had some hickups, and my usual welding issues, but here are my version of some taller, angled forward Cat bars.







Nice job you two , can't wait to see this bike run ! :thumbsup:
 
#64
I plumbed the puke tank as per Delray's suggestion, back to the engine. In this case, I am going back in to the drain plug. I retrospect, I should have tapped in to the case above the oil level for the return.

Also, the earlier discussed billet clamp for the puke tank was too thin and my since it was a 3/4 frame size, and my frame was 1", my opening up the clamp destroyed it. So I bought a much thicker clamp made for 1 X 2 and far thicker. It's used on shock reservoirs. Way better. Way more $$$.

Run test good today. Recap: OHH Billet rod, OHH 245 cam, Animal springs, Briggs FH retainers, new rings, .010+, roller bearing PTO, points engine set at stock. Mikuni VM22 shows with 17 Pilot, 120 main. About two turns out on the low speed air. No effect on exhaust baffle performance with no load.

[video=youtube_share;-NjO7Y3NLZc]https://youtu.be/-NjO7Y3NLZc[/video]

Direct Link https://youtu.be/-NjO7Y3NLZc
 

cfh

Well-Known Member
#66
watching the video... is this a monster to pull start? i ask because you really get it in the "right spot" before you pull. i don't think that hard with my motors, was wondering if the cam is making it this way? is it a bitch to pull start?
 
#67
Impressive! An actual pull start AND idle on camera! Sounds good :thumbsup:
:laugh: Yeah, I gave it a shot. There was a story going around that no one on here completes Tecumseh builds. I am very happy with how it runs with those modifications. Delray did a heck of a job doing the research and work for this legitimate and sane modification that anyone can do. Chassis testing next. :thumbsup:

cfh, a cam w/o a compression release will kick back hard, so we rotate them past the compression stroke before starting.
 

delray

Well-Known Member
#68
nice dave,sounds like you where easily spinning 4000+ rpm's from just just throttling it. tach wound be nice to have on it just to see what kind of rpm's you are pulling with it down the street. this way you can really determine if you need to fine tune the gearing up or down to get the max acceleration for your type of riding....:thumbsup:
a 15 pilot should put you about a 1 1/2 on the idle. that's where mikuni spec's say it will run the best. I have seen them run real good too at 2 turn's out. that will have to be up to you on your test run's. it will be interesting see how big of a jet that engine can handle. see you where using the choke. work's pretty slick. what did you think when you first fired it up on the choke and it started to run on high idle. I bet you thought it sound BAD ASS.
I think you will be ok how you got your oil return. might get little oil feed back up the line,but how much really is that? 1/8 of a ounce. engine can hold up to 21 ounces. my engine will burp little up line sometimes too.
get that chain on and run it hard towards your driveway and kill the motor while your on it hard at topend. then pull the plug.


might need a helmet:laugh:……...:thumbsup:
 

delray

Well-Known Member
#69
watching the video... is this a monster to pull start? i ask because you really get it in the "right spot" before you pull. i don't think that hard with my motors, was wondering if the cam is making it this way? is it a bitch to pull start?
a fresh motor can cause it too turn over hard. after dave gets it tune in and running good it will start to turn over little easyer….:thumbsup: it's not really that bad to pull it over once you figure how to pull it over in the right spot. engines that are real hard to pull over are the overhead engines with high compression and bigger cam's...springs...etc..


dave, dump that oil. you won't believe how much metal is floating in that motor now. dump it in a open pan and then look at the oil out in the sun light......:doah:
 
#70
I'm Impressed Dave ! That lil engine starts and sounds great ! But I knew it would ….good Job young man . And yes its best to get right by the compression stroke ...:eek::censure::censure: or else .
 
#71
Buttoned up some things and took her out for a test spin today. No seat, and no pegs, flip flops, shorts, somewhat of a "governor" if you will on my throttle arm. (I also had to replace that this morning) I had measured the cable too short before soldering on the Mikuni end.

Jets are now 17.5, requires enrichment to start, but quickly warms to no enrichment required, and 125 on the main. It really runs sweet, smooth, and I find myself wondering if there is a shoe to drop. I have never had an easier Tecumseh build, (I do points engines) and yet with all of the off the wall stuff in this engine, it is by far the smoothest, least drama filled engine I've built.

It's a bit sluggish on the take off, but the power carries it on acceleration pretty well.

I'm limited on what I can do to alter gear ratios. On the JS input side, if I go any bigger the chain hits the engine plate, if I go smaller, I overdrive the output. Conversely, if I go smaller on the output side, the chain will hit the swing arm. That leaves the clutch, and I can go from 12 to 10 on that. And yes, I have modified the plate to accept these larger sprockets already.

I'll get the pegs done up, and get a seat on it, and see how it goes. I'm enjoying the heck out of this build, and I do appreciate the comments above and earlier. :thumbsup:
 

delray

Well-Known Member
#72
Buttoned up some things and took her out for a test spin today. No seat, and no pegs, flip flops, shorts, somewhat of a "governor" if you will on my throttle arm. (I also had to replace that this morning) I had measured the cable too short before soldering on the Mikuni end.

Jets are now 17.5, requires enrichment to start, but quickly warms to no enrichment required, and 125 on the main. It really runs sweet, smooth, and I find myself wondering if there is a shoe to drop. I have never had an easier Tecumseh build, (I do points engines) and yet with all of the off the wall stuff in this engine, it is by far the smoothest, least drama filled engine I've built.

It's a bit sluggish on the take off, but the power carries it on acceleration pretty well.
I have found too that the 245 cam really likes to come on strong above 3000+ rpm's, the one thing that can help make it take off better is the gearing and high stall spring. I am running a 3100 stall spring right now . but I am thinking of going higher to help the bike accelerate better out of the hole for drag racing it.
lot of fun just buzzing it down the street at 3500+rpm's and then just nailing the throttle.

I like to see a torque converter setup on a future build. help on the lowend and still have top end too...…...:scooter:
 
#73
In keeping with the dirt bike theme or whatever it is I am doing, I scored the cheapest pegs I could find on Ebay. I fabricated some mounts out of a "too thin" set of Taco 22 triple trees that Mister Pat had rejected, but sent me as scrap anyway. Nothing goes to waste in my shop.

Spring loaded to the "down" (riding) position, in case the bike is laid over. Going up forward on the down tube section of the frame, and because of the taller bars, a six foot adult leg's can rest on them without kneeing the bars. I hope.





 
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