Crafting a kr250a1 motor into a dirtbike frame ???

[azwood80]

I know i cant beleve i missed the bent float the first time i had them apart so true who knows what knuckle draging poo slinging twat has played with them in the past

[Jeram]

That sharp bend straight out of the exhaust port is not going to be great.

I think I remember lozza mentioning that a nice straight section out of the exhaust port is ideal. I applaud you for having a go though.. I'm all about it.

my thoughts too,

even a MX bikes bend in the header kills a few hp

so a tight bend like that will kill a decent amont of power, atleast 5hp if not more.

but if thats the only design that fits then thats all you can do.

(appart from modify the frame or shock (what ever is constraining the design)

[EPApolice]

If it still leaks fuel from the drain screw take it out and have a look at the end of the screw where it seats. The drain screws in the KR carbs liked to get pitted and then never seat fully again.

[azwood80]

If it still leaks fuel from the drain screw take it out and have a look at the end of the screw where it seats. The drain screws in the KR carbs liked to get pitted and then never seat fully again.

the drain screws were working fine it was comeing out the overflow tube but with the floats set 3mm out of spec you would expect that as for the bend in the pipe its going to be hard to change without moveing the shock off to one side a little i will look into doing that if its posserble hope to take it for a ride on the weekend i will keep an eye on things and see what happends

[hybrid]

I wouldn't move the shock... I would put up with a few HP going missing personally.

[azwood80]

Just a little update on the bike went for a ride in the bush yesterday put some hours on the bike it goes awsome it has a load of power and its wicked fast the gearing is great for open tracks but i think i will go to a 12 front sprocket there is no need to go 180kmh in the bush i was just useing up to 3rd gear and thats fast as hell.still runs rough up to 1/4 throttle it feels like its flooding but past that its great the low speed jet is a 35 dont know if thats stock but i need to try a smaller one.also had i go on the road and was verry suprised at haw fast it is for a 250.

[Jeram]

Its a road race engine so you have a super-tall 1st gear and then close ratios after that

Sprockets will help a little, but the gearbox will never be properly suited to offroad

[azwood80]

The gearing isent as bad as you would think it actuly works pretty good i would say the a 12/13 front would better but i rides great

[azwood80]

I was thinking about the whole gearing thing and apart from the fact that i have a big rear sprocket to lower it for tthe dirt and the bike would be lighter than the kr is my pipes are probley helping to the kr,s seem to have a longer belly in them where mine mucth shorter.i dont know what else to say it works alright logic might say outherwisut i need a go- pro vid up on you tube thats the onley way people can see what its like.

[JonW]

Im keen to see the video, loving the fact you built this so quick, enjoy!

[azwood80]

[quote="JonW"]Im keen to see the video, loving the fact you built this so quick, enjoy![/ i supose it has gone together fast its been a lot of work but its been fun at the same time had it on the bike trailer the outher day had a few people scra gtching thair heads as they went past lol

[azwood80]

The full gaskit set arrived today it has everything from head gaskits to sump plug washer and pipe seals naw i can inspect my piston/ barrals and see whats i need of replacement i no the crank seals go on thease is that a big job if the covers are off.??

[azwood80]

Made up a custom 12t front sprocket just to see what happend well its a completely diffent beast naw its almost too shortly geard but i will see how it goes in the tight stuff i may go to a 13t i depends where im rideing..

[azwood80]

Just about ready to bolt the clutch cover back on when something confused me.there is no marks to time the crank gears to the main gears behind the cluch basket the one thing i forgot to mark when i removed them............... Damm it there is lines on the crank gears but none on the main gear do i need to find tdc and bdc with a dyle indercator then drop on the gears at that point or is it just point the marks to the main gear where it looks like the nearest tooth is to being wright.

[azwood80]

Have the main drive gears all sorted naw so hopefuly its up and running next week it will be interesting to see how shaveing the head and mildley porting the rotery valve houseing go