ideas for 200cc racing engine (horozintal engines)

[oscarmayer]

here's the deal, next year my son will be competing in the 250cc class, but the bikes and chassis we run are the horozintal style engines (70-125cc) (we do not want to chagne the bike otu as theya re awesome machines to run as is). I measured and a normal 200cc will not fit. The cost of getting a KLX110 and doing the mods to turn it into a 200+cc engine will be 3Xs the cost of a normal 200cc setup even with a few minor mods.

Anyone got any ideas? i read about the 200x laydown motors. Does someone have oen of these or at least the cases for one? i coudl always get a 200x and use the egine and the laydown cases to make it work. anyway, any ideas are welcomed. if not, Guess i'll be doing some custom work to make things work. (done it before so meh...)

Thanks again for looking and feedback is very welcomed.

mike

[Vealmonkey]

I've got 2 sets of the laydown engine cases. If you are worried about cost, then you shouldn't even be looking, cause the cost of a set of cases alreay modded will knock your chin in the dirt. Not trying to be mean, just saying.

[oscarmayer]

appreciate it Veal. I pmed ya for details. any otehr ideas out there anyone?

I knwo i need to get shortline my 200x muffler. I told gim he could have it. so i have not forgotten shortline. work kicks my tail man. sorry.

[shortline10]

No problem LOL . What about a atc110 motor stroked to 180cc now thats a hand full of motor for ya ........
or see is Greenhuman will build you one of his crf230 laydown motors ?

appreciate it Veal. I pmed ya for details. any otehr ideas out there anyone?

I knwo i need to get shortline my 200x muffler. I told gim he could have it. so i have not forgotten shortline. work kicks my tail man. sorry.

[oscarmayer]

crf230? hrmmm *scratches head*
the issue i have is my son is 9 right now and i am trying to teach him how to properly use the shifter this year and use gears for the correct area meaning shifting for hills or for straights and corners. so once he has that down pat, then he woudl be ready for a bigger class, but next year he will be 10 and using a manual clutch at 10 will be hard to pull the clutch in for him and shift, let alone not stall the bike. any ideas on a semi-auto 200cc laydown? ye ai know I'm asking a lot.

[big specht]

I think a 125semi auto will be big enough for him for a while If he don't have very much experience in riding a hopped up motor

[briano]

I think Shortline is on to something with the 110 motor. I have one in an atc70 with a 123cc big bore, cam and a pipe. This little bugger will blow your hair back. Otherwise some of the china motors are close to 200cc and can be built up from there. I have a 140 Piranaha in another 70, and it is a bit faster than the big 110 but the semi-auto is a lot more rideable.

[oscarmayer]

he rides a very hopped up 125cc with a 134cc upgrade, 15:1 compression, custom porting work and more. These motors are pusing the 17-18hp limits. no rev limiter on them eitehr so it revs to the moon. By the end of this season if all goes well, he should be ok on a 200cc laydown (issue right now is shifting). once i get his new engine (thsi season's) finished up and runnign we will go to the practice track near the house and i'll take some videos, you guys can watch the little guy at work. he's pretty awesome to watch. he nearly outrides me at times now. lol but i'm an old has-been so not too hard to do. hehe

[Vealmonkey]

Why don't you see about adding a clutch to one of the old engines, detune it a little and turn him loose. Wether you or he realizes it or not, unless the engine design is completely different, every time he has to auto shift up or down, he is activating a clutch. Is his engine a single speed? If the engine is not a single speed, then he should have all the basics down already. Then you need to build a really mild engine with manual shift that may be a little clutch sensitive.

[oscarmayer]

yea i know he's running a clutch, but i am not sure he can manually activate it at his age due to hand strength and coordination while racing. i do have a spare manual shifter, and we do have a practice bike, so yea that would be the best bet for sure. I was actually going to set his practice bike up just that way so i can try to teach him. i guess i can't shelter him for ever, he's gonna have to learn at some point. if i can get him leaning then we can just buy a bolt in 187cc clone engine for around $1300 and be done with it. they produce around 28-30hp in current form before you add in major upgrades (like dual cam heads and such) and that would save me all the hassles of custom stuff.

I'll keep everyone posted and like I said, I'll get some videos if his practice so you guys can check him out.

motors i am looking at.
http://tboltusa.com/store/engines-wo...c-114_518.html


here are some of the details I'm looking at now.
stock engine:
52.4mm bore x 57mm stroke cylinder is 78mm long and valves are 25/21.5
stock hp=8hp
9.25:1 comp flat top piston

current setup:
54mm bore x 57mm stroke 78mm cylinder valves 28x23.5 race cam, and spring set
hp= 17
15:1 comp with hi domed piston

this is what we will be running this year. I have 2 different engines we are going to use. 1 has longer gears for longer tracks with standard hill sets, the other is a shorter geared tighter gearing for tracks with lots of larger hill sets.

anyway, just wanting to give some of you a glimpse into racing and the involvement and what it takes. for example, the stock engine location, the bottom mount bolt cannot be removed w/o taking the swinger off as it hits the swinger edge. I cut away part of the mount section and cut off the entire top mount and make a custom setup where it moves the engine 1 inch forward. This now allows me to remove that bottom bolt w/o taking the bike apart and makes it easier to do engine swaps track side. The next issue we had was we kept bending the stock sized engine mount bolts. The stockers are 8mm diameter. To resolve this issue, I drill out the engine casings holes where the bolts go through to mount the motor to the frame to 10mm and the new mounts I make have the 10mm holes. This allows me to use a grade 8.8 10mm bolt (vs. the stocker softer 8mm bolt) and no more bent mount bolts. trust me, when your track side trying to swap a blow engine out *he missed shifted up a hill in practice causing the engine to over-rev and float a valve into the piston this no more top end)in less than a hr (motos are usually about 1hr apart) and the bolts are so far bent you have to use a hacksaw to cut them at the mount point it sucks (to bend to get out of the engine casing).... anyway, the old saying goes, if racing was cheap and easy, everyone would be doing it.

[oscarmayer]

Here are some photos of the frame I worked on before being sent off for blasting and coating. You can see the engine mounts I made or modified in here along with other areas I modified if you got a keel eye.

[hippyplz]

What chassis are you running?

[oscarmayer]

the chassis was based off a simular to the old xtreme typhoon series (same as baja storm, or msa-125a from JCL or leopard or the ssr125) the issue they had was framing was not correct for racing. it looks cool, but that's it. I had to do a ton of support and re-design to make it race worthy. so the bikes I have are proto-types. I know of 1 more proto-type in the create that when i go home to visit, I'm grabbin it and leavin it alone in the create for the day I need to redo it. I actually helped the current maker re-design the frames to be more stable and much more stronger as well as added extra stuff they did not (aas you can see from the photos).

i have some other photos, I'll toss up shortly. the bike is 90% completed so I'll toss up some of those photos tonight.