Jump to content
Sign in to follow this  

RHC 187 cams, 434cc BB kit, FCR39 Jetting?

Recommended Posts

I suspect this is a combo that's been done once or twice before, but most of the RHC builds I found in the searches were with stroker cranks, which I'm not planning (at the moment... :smashpc:)

What jetting are people running with the above?

I know my current exhaust will be strangling it a bit (it's not an MRD/SSW or a Yoshi Ti, it's a run-of-the-mill full system with open can). I may be tempted by another pipe at some later date but it's not part of the current "refresh" plan.

To be honest, I'm only going so far as the RHC 187s and RHC valves because my stock camshafts are shot (well their sprockets are, knackered camchain) and I got a good deal on the RHC kit (unused) on ebay (the valves are still in the box that Eddie sent them to the UK in!). And the BB is happening because the head'll be off anyway to fit the valves, and it'd be rude not to with those cams... You see how this has snowballed...? 👍

Share this post


Link to post
Share on other sites

I don't know anything really but my understanding is those cams were designed for stroker motors and have too much duration for the stock stroke? With that kind of duration they will really only work at high rpm and without a pipe (mdr/ti) and carb (fcr 41) to support the rpm it fall flat. I think ya may end up with no bottom end or top end? If ya were on this side the pond I'd trade ya set of nos stage 2 hotcams I'm gonna maybe try in a stroker build (fcr39/mrd).

Share this post


Link to post
Share on other sites
+2 on that.start with the settings stated in this thread and report back

Will do once I have the other bits installed. FCR just arrived and doesn't look promising - its the sort with the cast cable mounts etc, though the vendor says he had it on his SM... Yes, I know, I should've bought the TT or Epic kit - but paying import duty on top of US retail price sucks so if I can get something from within the UK/Europe I'll usually give it a try. This one may have been a mistake, however... 👍

I'd hold off on the cams and buy a MRD/SSW if it was me.

If this was a straight performance mod, that's what I'd do too - but my exhaust hasn't been trashed by a worn camchain and my cams have. And you guessed it, the price of the secondhand but unused RHC kit from within the UK was less than hotcams + import duty! Hence the slightly arse-about-face approach being taken here :smashpc:

Share this post


Link to post
Share on other sites

Can do. Not popped it open to check the jets etc - wanted to see if I could physically get it in there first. If I can't I'd like to still be able to send it back...

Share this post


Link to post
Share on other sites

Here's some pics of it dude - was about to head out to the garage with the camera, then remembered the pics off the listing.... :smashpc: They're not great but you get the idea.

carb5.jpgcarb3.jpg

The bloke says he had this fitted to an '08 SM, with similar mods to those mine currently has (airbox and pipe), so for the moment I'll give him the benefit of the doubt. Just not at all sure how I'm gonna get it in there with the bits provided...

Share this post


Link to post
Share on other sites

Hmmmm.... Still not looking promising.

Have been trying to get it in, have sent the pics below to the vendor, to find out how he managed to get it into his bike. Any ideas from any interested parties gratefully received...

IMG_2892.JPG

IMG_2891.JPG

IMG_2889.JPG

I should have sucked it up and paid the import duty on a TT or Epic kit!! :smashpc:

Share this post


Link to post
Share on other sites

It's a 3rd generation Fcr / 2nd gen FcrMX , it has a non removable air bell intake to the air boot and it has a cast cable tower .

It's not going to be a bolt on , it will need a lot of mods .

Share this post


Link to post
Share on other sites

Thanks for the info, even though it's not what I wanted to hear! :smashpc:

Not quite the bolt-on kit that was described, though I'm increasingly intrigued as to how matey boy got it to fit and run on his bike. I'll wait for his response, but after the time on here that I should have spent before I hit the "Buy it Now" button, I'm doubting my judgement!

Interestingly, the "E model" airbox boot supplied with this carb doesn't have a fitting for the breather pipe - is that normal? Are E-models open breather? I assumed the E-model airbox boot also had the same fitting...

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...