KIPS motor/valve question

TC · Post by TC » Mon Jan 14, 2008 9:55 am

Coming towards the end of my rebuild of the bike I was given as a non-running hulk. The engine is back in the frame and I thought I'd check out the KIPS system after fitting new cables in place of the frayed rusty ones.

Nothing.

Disconnected the cables and the motor does actuate and return when the ignition is switched on, however it seems very weak - I can hold it with my hand and stop it turning.

Possibly the slave battery I was using is a bit tired or I've got a high resistance earth, but I'd have thought if the motor was going to work at all it would have a reasonable amount of torque?

The valves themselves went back in as they came out - I haven't stripped them and they were presumably working before. There is some resistance to turning but they turn easily by hand, certainly not what I'd call stiff.

I'm not used to the quirks of the KR so any advice would be appreciated!

mgtkr1 · Post by **mgtkr1** » Mon Jan 14, 2008 11:01 am

sounds like a duff battery to me, if it didnt turn or turned when it felt like it i would of said kips motor or possibly cdi but as it turns albeit weakly, this suggest the power source to be the cause. i would whip the kips covers off the side of the barrels and just see how caked in carbon/unburt mix the covers are? the powervalves may need a clean/de-coke if its bad but if its just oily then this should be ok and shouldnt effect operation. make sure the kips cables are only as tight as they need be, and no tighter as this puts excessive strain on the motor and burns it out. can also lead to cdi damage i think? give the cables etc a liberal dousing with WD40 prior to testing with a decent battery.

TC · Post by TC » Mon Jan 14, 2008 11:11 am

I had the complete motor apart so the KIPS system came out, but I didn't strip the head or take the square covers off the side of the barrels. As I say the valve system does have some resistance to movement but it's not what I would call stiff. I didn't know what to expect in the stiffness of the valve system or the ability of the motor to turn it. Cables should be OK as they are both brand new.

Thanks for the feedback!

the-elf · Post by **the-elf** » Mon Jan 14, 2008 12:56 pm

Sounds like the battery, Check that first.

Did you dip the PV's in two stroke oil before putting the head onto the barrels?

TC · Post by TC » Sat Jan 26, 2008 1:57 am

the-elf wrote: Did you dip the PV's in two stroke oil before putting the head onto the barrels?

Cleaned em, didn't oil em. Reckoned they'd get oiled first time the motor fired up.

mgtkr1 · Post by **mgtkr1** » Sat Jan 26, 2008 4:30 pm

have you tried another battery yet? if they turn with reasonable ease they shouldnt be the problem but i alway strip,check and lube everything when the head comes off. they should turn without any resistance ideally but i still thing a weak power source ie battery is the answer. take the square covers off and get some idea of how much carbon deposits there could be. if its fairly wet but no hard carbon bits then chances are the valves should be clear of carbon, any hard bits indicate its decoke time unfortunatly. the carbon can partially block up the valve port windows, that costs a bit of power though not much, just can cause valves to seize. i always polish the valves cutouts too avoid build up as i do with the head and also the ex port but i dont mirror finish that, just make sure its smooth and free from imperfections, on the cool charge (pre-combustion) side of the motor ie transfers/boost port/intake i do the opposite and leave a unsmooth finish to aid atomisation. this side of the motor doesnt get coked as such, just combustion chamber/ex/p'valves. hth, cheers matt

nate · Post by **nate** » Sat Jan 26, 2008 8:22 pm

doesn't help but, my valves twiddle around really easily ...

I must admit that there was loads of crud in the holes where the PV go, when my head got pulled apart this week...

It may be worth whipping the head off and giving it a good old wash and clean up