Got my puller yesterday and installed Penland offset key last night. I formed a peice of copper conduit with a hammer and a file to slip in front of key to make sure flywheel stays advanced upon tightening. Performance very disappointing. I gained no top speed and the only noticeable difference was a bit more backfiring when letting off gas and bike seemed flatter at full throttle. I will readjust pilot when I get a chance to address backfiring, and I am thinking that maybe my dial a jet is finally working(not sure though, I dont think the air cleaner mod and the muffler mod had me lean enough to utilize the daj because i got same response on all settings.) DAJ is presently on factory setting and this weekend I will try leaning and or richening to see if I get a response. Still slowassmolasses. I am very interested in the previous thread about shaving the head down, but I was told if too much compression is made, you will get a knock???
Can anyone answer if a valve timing retard is made, does this increase horsepower or just change where your powerband kicks in??
Stay tuned, I am not done yet.

 

OMM... sorry the key wasn't "360 magic"... but you are at the cutting edge of 360 performance...I wonder about cam timing ??? I doubt much, if planing the head will provide "too" much of an increase, but ??? there must be something that can be done, as in stock form, the 360 doesn't have any more power than my old 300 Prairie... & that machine can easily see benifits from easier breathing, etc... keep us informed as you move forward... have you thought about changing out the primary spring ??? or adding a shim or two to the stock primary spring ??? this very possibly could help your acceleration, but wouldn't help your top end speed...

 

Oleman, newbeetle is right about you being on the cutting edge of 360 performance. A year from now, 360 owners will be speaking all the time because of the things you are FINDING OUT about the the 360. The key here is you have to find them out, because we can only offer advice. For instance, we don't actually know if your timing is retarded.

Compression: people have been adding compression to their quads for ages. It is one of the easiest methods of gaining horses. It increases volumetric efficiency, which means the engine moves more air in and out. It could knock if you get the compression too high while burning low octane. Raising the octane should prevent it. Your compression is only 8.3:1. that is sortof low. You could go to 9.9:1 like the prairie. I think it would make a big difference, but it might need 93 octane from the corner gas pump.

Valve Timing: if you retard the timing, it will make approximately the same shape power curve at a higher rpm range. That means more horses. You may need to adjust springs and weights to more fully utilize the change in power curve. Higher compression may help not loose so much low end if you do it at the same time.

Valve lift and duration: that is a science that makes or breaks and engine's power and you can't mess with it without having someone regrind your cams.

Port work: If you take the head off, have a professional look at the ports to see if they could be improved. You won't really need flow benching on one head.

Valves: It might take some research, but you can get larger valves installed. That can sometimes have a big effect. It depends of how small the stock ones are. The thing you have to watch for is will the valves hit the head. You test this with clay on the piston.

Ign timing: you might be at optimal advance right now. You know better than we do. Before you take the offset out, try premium fuel and see what that does. Also, are you sure you went the right direction?

Displacement: the prairie piston is 82mm, yours is 80mm. You might look into boring. That would make it 380cc. Your stroke is already kinda long at 72mm. Mickey dunlap would be able to make kits for it, but I doubt he would since it would be more cost effective to get a bigger quad.

May the force be with you.

 

with no real difference with timing key makes me think you want to be sure it is in right way. wrong way would make it feel like you're in 3rd gear instead of 2nd. advance the timing and it should always feel peppier unless it's to far advanced.

 

I drew a very crude picture of the crank-key-flywheel rotation and copper shim I added but do not know how to insert in link---might make me feel at ease if I could show it to you guys to confirm it is right---although I think it is---especially with backfiring I am now getting upon decelleration-(lean condition)--If looking at flywheel---with ccw rotation--if my keyway on flywheel was at 12:00---it is now at 1:00(exaggeration)with crank keyway still at 12:00

Does this sound right??

 

It sounds backwards... the flywheel should rotate more towards the frontof the quad, rather than rearward... SORRY, but sounds like the key is in backwards, ( or upside down )...

 

Put that hummer at 11:00 (or 11:45). You retarded the timing.

When you test it, lean over the handlebars with your helmet as close to the front rack as possible in case it wheelies on you.

Lol, JUST KIDDING. You probably don't want to race against a 650 yet.

 

good news, you get to do it again only this time with gains on your top end.

 

YIKKEESSS! Sometimes I am an idiot---I meant to say I moved flywheel to 11:00 with crank at 12:00---sorry for the slip---
In relation since engine spins CCW my flywheel is firing sooner than it was without the offset key
Read my new thread "Santa Clause" I may be on to something