HPP powervalve

[evo550]

Trying to get one of these back together, and seem to be stuck on the spring set up, I'm trying to work out how the top of the spring mounts, there are no lugs or recesses in the housing for them. It's from a 86/87 model. 88/89's where different, which is what my manual shows


In this position it looks fine, but has no tension, but I cant rotate it 360 degrees without seriously dsitorting the spring. Any thoughts.

[Hotelmoto]

Evo

According to the Clymer manual, On the left-hand side rotate the spring counterclockwise 1/2 turn & hook the straight edge onto the ledge on the cylinder, and on the right side rotate the spring clockwise 1/2 turn and do the same, this is before you install the top collar.

hope this helps.

[evo550]

Thanks moto,
I managed to fiddle with it and get it to sit right, but now the push rod that activates the valves seems to be working in reverse Fcuk

[Hoony]

i have done this job many times, but it's been 6-7 years since i last did it as my 250 is in storage.

the valves are open when cylinder is not on crankcases, you use a screwdriver to turn the RHS ( i think) valve to move the rack so the cylinder can locate, the rack locates over the cam protruding from crankcase when the valves are closed by the screwdriver. i have a original Honda shop manual if you have trouble i can scan it over the weekend.

let me know how you get on mate.

[evo550]

Hoony you bloody ledgend, you have just solved the problem, I have been setting it up with the valves to close when cylinder is off the case, which has bambozled me with the position of the push rod.
I need to reverse the springs so the they are always opening the valves, not closing them.
The manual failes to divulge that piece of vital information. I'm a Happy Honda HPP person again.

[Hoony]

Great, glad that helped. i can feel your pain as the first time i did it i spent hours on it ( Rubiks cubes were easier to solve)

Inspect the weird shaped circlips that go over the Valves, i have had a few snap from Fatigue.

[Hoony]

how did you get on EVO?

[evo550]

....It goes together quite easy, when you now how
Now just have some carburation issues to sort out.