CR(M)250AR SUPERMOTO BUILD

[Jeram]

progress is now rapid


My biggest issue now is that the PWK38 fowls on the frame with this intake boot, Iv ordered a new45 degree silicon hose and hope that that will do the trick, if not Ill have to cut into my bling manifold to bring the carb closer to the engine.

[2TInstitute]

I would either put a thicker gasket between the reed and the cases or make a thin wedge to go under the manifold.

[Jeram]

cheers, the wedge is a great idea,
I was hopeing to get the 45 degree bend and then cut it in half to get a 22 degree bend.

Im just trying to weigh up a few options, If I shorten the intake manifold slightly and use a slightly bent hose I will be able to connect to the OEM airbox,

but If I go with the wedge idea and keep it nice and straight I will have to ditch the airbox and run no filter or a pod filter.


and I finally worked out why my ignition has 2 pulse generators and 6 tabs on the flywheel.
the bike can count where TDC because thats when both pulse generators are triggered (double pulse)

then depending on the bikes RPM it will switch between using pulse generator number one and two, aswell as counting the number of pulses after TDS.

so for instance at idle it might use pulse gen 1, and will fire 2 pulses after the TDC double, (13 degrees advance)
and then at 8000rpm it might switch to pulse gen 2 and will know to fire 1 pulse after TDC (17 degrees advance)


so I need to keep the 13 degree advance tab and the pulse generator that it coincides with.
then the fully programable ignition can control the rest.

[2TInstitute]

be fun ripping the loom apart.
Don't ditch the airbox they go better with an air box. Use the bend to go to the airbox

[Jeram]

I will try to get the airbox to work, even if I have to cut the current plastic manifold off (between airbox and carb) and replace with peice of 2.5 inch silicon hose.

Im going to leave the electricals untill very last, its the one thing that scares me.

[Jeram]

a kind member on CRM250.com supplied me with this

OEM ignition pulse map



its for a slightly different model, but it should be the same as mine

[2TInstitute]

something like this might be better?
http://cgi.ebay.com/ebaymotors/2002-HON ... 3a68737bef

[Jeram]

perhaps, Id just have to have a look at the CR cases and see if the pulse generator is located at the same spot as on the CRM.
but I suppose that a bracket could be made to relocate this to the correct spot if needed.

then make sure that the tapered shaft and woodruff key all match up.

[2TInstitute]

Keyway/pick up position is not important with the Ignitech

[Jeram]

ok great, thanks for that,

because all I need to do is tell the ignitech how many degrees from TDC the pulse occurs (wherever it may be) and then it does the rest?

that makes my life easier, so all I have to do is find a flywheel that will fit my crank (std crank taper for all honda singles???)

I had a look around and found that CR250s from the same era have a stator/flywheel that looks like a good match

PIC URL :
http://i.ebayimg.com/02/!B52v+ggBWk~$(K ... Q~~_12.JPG


in other news

I spent a couple hours last night just removing bolts that I put in threads during the powdercoating process, I made the mistake of threading the bolts through too far so they came out the other side. very frustrating.

then when I went to remove the bolt, the hex head was smaller (zinc dip and powder-coated) so I had to find a closest fitting hex key (imperial worked well here), and the thread protruding on the other size was larger so would not pull back through, for most of them I had to make a special tool to hold a thread cutting die in the tight places, and had to re-cut the protruding bolt shafts haha...

for anyone looking at powdercoating for the first time... learn from my mistake: preparation, preparation, preparation !!!!

the bike is coming along well, Ill post up some more pics tomorrow once I get further along,
I just need my wheel bearings to turn up this week and then I can get the machining done for fitting the front and rear wheels soon hopefully.

then with a bit of luck machine the PV and lightly touch up the CR cylinder with lozza while Im in newcastle in 3 or 4 weeks time, and can post it to myself before I fly home

[DOC03]

Coming along great, the electrics is what scares me too so im getting Lozza to help me with that !!!

Thanks for the heads up on the Powder Coating. I always thought it would be a pain when you get it back, how to remove the bolts wihtout stuffing the surrounding new coating, so I decided to go with a Paint Job.

What would you do differently next time to prepare a frame ??

[2TInstitute]

Ahh a 'good' powdercoater will use bungs(like test tube stoppers) in all the concealed threads or bores. We have a good powder coater here in Newcastle, they are 'bike blokes' (one owner is a life member of the Gladiators and currently rides VMX, top bloke too,just don't get on the wrong side of him, pretty sure all their accounts are paid on time , might I digress) they will do all that for you. Pro Strip in Redhead Rick/Cliff/John they do ALL the bro's work

[Jeram]

Coming along great, the electrics is what scares me too so im getting Lozza to help me with that !!!

Thanks for the heads up on the Powder Coating. I always thought it would be a pain when you get it back, how to remove the bolts wihtout stuffing the surrounding new coating, so I decided to go with a Paint Job.

What would you do differently next time to prepare a frame ??

I would have bought cheap nasty bolts for the job and not put the thread all the way through and out the other end. or as lozza said, just put some rubber in there.

and I would have remembered to seal up my headstock, a mate spotted that before he dropped my frame off and because hes such a nice bloke he got some threaded bar, 2 large washers and some nuts to seal that area shut for me.

overall Im very happy with the job, it was just a few hours work to clean it all up afterwards

[Jeram]

by the way, if your side-stand lug is warn and loose, powder-coating/zinc dipping will bring it back to factory tolerances haha

[Jeram]

hello ignitech