upgrades and the real stories behind them!

[Bones]

hay guys. now this may seem stupid and all but i have been hearing from several sources different stories about irk's, hc pistons etc etc... i would just like to clear a few things up for one myself and two the fellow readers on this forum that are just as confused as i am.

firstly and the biggest question on my mind is a combination upgrade. fitting an inner rotor kit. now i have heard several stories about how this is done, what needs to be done etc... and there are a few questions that keep jumping into my head about this upgrade. firstly it would have to do with the clutch assembly, having the clutch on the main shaft or the clutch on the crank. how do you tell the difference between the two?? is there some identifiable way to tell the difference from the exterior of the motor or do you have to take the "housing" off to see the differences internally?

once this is detirmined we can begin to fit the IRK but then we get to the oil slinger. now i understand that this has to be ligntened, this i can understand the reasoning behind as i am sure everyone else can but the biggest question comes to the hc piston. i have seen written down in several forums that if you fit your bike with an irk that you shouldnt use a hc piston as well, some say if you have a irk it is fine to fit a hc piston. now this just confuses me, can we have a hc piston with an irk or not?? and if we do put a hc piston with an irk are there any situations / scenario's we should be aware of.??

if anyone else has any quetion marks about an upgrade, throw them in here so we can all learn the real stories behind these upgrades, the best options and what we should take into consideration for future refrence.

Cheers, Tony.

 

[noidea]

With the clutch; If its on the main shaft then you can start in any gear (or visa versa?).

The problem with fitting an IRK and a high comp piston together is just starting the bike. Have you not read about having to roll start a bike with IRK and high comp piston? This is because the kick-back will shear the starter gear and/or crack the housing. This is the only problem, you might also have to run slightly higher idle rpm to give the engine enough momentum to compress the charge and keep it ticking over.

so the IRK is going to give you better throttle response and let your bike rev up quicker. Also lets you adjust your timing.

High comp piston increases compression giving the engine more power.

Its perfectly ok to use these two together if your willing to roll start your bike every time you ride to save you shearing your starter gear or cracking the housing.

 

[Dreadful]

Unless you ride in sand seems like a no brainer .... Epod lives up the road and is in the process of fitting one .

He can swing a spanner so I'll see how he goes.

 

[mjc85]

Apparently you won't have the kick starting problem if you stick around 9:1 - 10:1 compression so i hear, and so i think because the 141's motovert are using are 9.2:1 and i don't think they'd sell a bike that you cant kickstart as they would have a heap of warranty claims.

 

[Dreadful]

Yeah mjc85 that sounds logical too me on both counts.

 

[noidea]

yea if you wana keep kicking you have to choose between HC piston or IRK. Or mayb do some work to stiffen the casing's or wat eva is going on there. Roost might have some ideas i think hes killed a few.

 

[don351]

how high is the comp gonna be with the hc piston cause if its over 10:1 id start runing a higher octane fuel with it like avgas

 

[roost]

how high is the comp gonna be with the hc piston cause if its over 10:1 id start runing a higher octane fuel with it like avgas

this does help

 

[biggerboyztoyz]

Just a quick hint, If you give the top end to much your box will suffer, in particular 2nd gear.

 

[Mack]

Heaps of guys run both hc and inner rotor. Just gotta learn to kick it. Also this problem is made worse by guys advancing ignition too far. You gotta find balance.

Or my preferred option would be to lighten the flywheel and oil slinger.

Just out of interest on this subject..I am currently investigating two solutions two this problem for the ideal setup. A fully programmable ignition, so the ignition can be retarded for starting and then programmed perfectly for the entire rev range. Also a decompression lever cabled to lift the exhaust valve or a decompression button as used commonly on harleys.

 

[roost]

Heaps of guys run both hc and inner rotor. Just gotta learn to kick it. Also this problem is made worse by guys advancing ignition too far. You gotta find balance.

Or my preferred option would be to lighten the flywheel and oil slinger.

Just out of interest on this subject..I am currently investigating two solutions two this problem for the ideal setup. A fully programmable ignition, so the ignition can be retarded for starting and then programmed perfectly for the entire rev range. Also a decompression lever cabled to lift the exhaust valve or a decompression button as used commonly on harleys.

keep us imformed on the decomp system if you could , i'm very interested

 

[Mack]

I'll start a new thread on this one, it definately needs attention this problem.

 

[Bones]

thats very interesting mack. im keen to hear how you go about all this. let us know how you get on with it all.

Cheers, Tony.