Honda HRC 450RR

[250rfan]

Do you have to run that carb?I am wondering if a Edelbrock aftermarket carb would fit better.More performance too.I would think a aftermarket carb,wont have that extra box on it and may fit without cutting the frame.Just a thought.
I am getting ready to put the 07 450R swinger on my 250r build.Can I use the stock 250r shock?I searched the forums and saw another member had to file the 450r swinger to accept the stock R linkage.So my question is,Will the 250R shock and linkage fit without modding the shock mount?
I heard they sit a little high in the rear after the 450R swinger is on,but I have a durablue lowering link to use,so that is not an issue.Also does the 86 250R axle fit the 450R carrier?
Good build 250Rfan.Cant wait to see it done

Hey Mosher,

Jeez, a few questions there, okay - ye the Edelbrock was an option a looked at, but i was'nt keen on spending the money just to find out that i still needed to cut the frame, if i had acess to an Edelbrock to try i would have went down that road.
But cutting the frame is'nt as bad as it may look, there's not that much metal removed and i have plated it up inside using 6mm plate - it's probably stronger now than before. Also Rob there's electrical sensors or something on the carb which plug into the wiring harness, it's esier for me at this stage just to use the OEM carb, basically because it's allready set up for this engine.

As for the swinger, i just checked, the shock linkage should fit into the 450 swinger no problem, you may have to make up a couple of spacer to go either side of the lowering linkage, as the lowering link is 4mm less in width than the 450shock linkage mount on the swinger.

I also slid a new 85/86 bearing over my 450 axle - no problem.
The OD of the 450 axle is 39.91mm or 1.5715" at the bearing placements.
The space between the bearing placements on the axle is about 5.67"., so i guess an 86 axle may well fit into the 450 carrier.

Thanks for the complements Rob, i saw the one in DR. Deaths thread also, if you like my 86, your really gonna like this bad boy!!!,,,,,

[ChrisD]

All I can say is.....do you wan't to sell it?

That is awsome. Will the stock tank (or short track for that matter) still fit over the top of the motor. That motor is tall. I would love to turn my 85R into a 450, so this thread is a real help. I love it.

[250rfan]

All I can say is.....do you wan't to sell it?

That is awsome. Will the stock tank (or short track for that matter) still fit over the top of the motor. That motor is tall. I would love to turn my 85R into a 450, so this thread is a real help. I love it.

Hey Chris,

Ye Chris, the stock tank will fit and HAS BEEN fitted, it needed some altering but as you will see in the upcoming posts it's not that hard to do. I have also started modifiying the short coarse tank, just as an alternative.

I'm trying to take as much pictures as possible during this build so that hopefully after the build is complete anyone who's thinking about upgrading there 85/86 250r atc/parts to the newer OEM or Aftermarket 450r parts will be able to see exactly whats involved and how to do it.

Mmmmm, it won't be for sale when completed, but i will have a template as far as the frame is concerned ,

Thanks for the complements,

G.

[350xBomb]

What's the weight difference between the 250 and 450 engines?

[3Razors]

The Keihin FCR carbs are a much superior carb over the Edelbrock. Lots of riders have tried those E-carbs and haven't found any performance increase over the Keihins.

[250rfan]

What's the weight difference between the 250 and 450 engines? - the 450 engine weighs 78.3lbs

The Keihin FCR carbs are a much superior carb over the Edelbrock. Lots of riders have tried those E-carbs and haven't found any performance increase over the Keihins.

- looks like i made the right decission not to buy one!



Okay, here's an update

Now that the engine is in, and the swinger and the carb fitted, i have went back to the frame and finished the front of the frame as far as tying it in is concerned.

I will have pipe machined the correct OD & ID then wrap it over the inserted pipe shown, weld and flush, as done previously with the main frame tubes. Once finished you will never know its been cut and welded.

I have also made the front engine mounting brackets, using the original OEM ones.

In the last picture you can see i have used the OEM upper rear suspension mounts from the donor frame, to make the new upper rear shock mounts.

[Louis Mielke]

I'm assuming that the upper shock mount is only temporary untill a better one is welded into place?

[250rfan]

I'm assuming that the upper shock mount is only temporary untill a better one is welded into place?

What exactly would a BETTER one be?

[Louis Mielke]

Hey now, didn't mean to offend, let me rephrase. I'm mearly saying that so far all of your other welds are almost invisible, the shock mount welding, eh...not so invisible. What are the plans for the mount if any...

That better? lol. :-) Didn't mean to ruffle any feathers, you seem very good at your modifications, I figured there was more work to be done there. Sorry if I was wrong.

[250rfan]

Louis, no feathers ruffled , as it happens there was more work done, after the frame/mounts for suspension/rear brake master cylinder mount ect were tacked /welded together, i took it to a friends workshop where all showable welds were ground and replaced by TIG welding prior to the frame going for Powder coating. A lot of the welds you have seen so far and will see latter were only for assembly purposes, just to make sure it did'nt fall apart while test riding.

[250rfan]

Well, now that the engine is in the frame, the rear swingarm/suspension & carb are installed, it's time for the next issue - THE FUEL TANK.



The first pictures show the HRC short coarse tank mounted on the bike, you can see where i have had to cut the tank to get it to clear the left hand side of the engine.

This is not the tank you see in the other pictures, i have modified a standard tank instead, i just put these pics up to let you see the tank and how much had to be cut out to make it fit over the 450 engine. There is no alteration needed on the right hand side of the tank.

[Mosh]

Thanks for taking the time to answer all my questions.This is a great build and post follow up by you.Keep up the good work.

[250rfan]

Okay, these pics show the standard tank and the process of cutting, fitting, and plastic welding.

I cut out the required amount to clear the 450 engine.
Then i made a template using card to get the rough shape needed.
Then, i cut a piece of plastic from a donor 250r tank using the template.
The cut piece of plastic was then folded in 2 places and grinded/filed to suit the cut out on the tank.
Then the formed piece of plastic was welded in place using a 5600HT Mini-Weld Model 6 Airless Plastic Welder.
The fuel cock had to be removed when the tank was cut to allow the tank to clear the engine, so i had to shift it along 2" or so to the end of the tank, as you can see.

[250rfan]

Here's the last of the tank modification pics,,,,, ANOTHER ISSUE SOLVED.

[250rfan]

Thanks for taking the time to answer all my questions.This is a great build and post follow up by you.Keep up the good work.

No problem Moshman, glad i could help, let me know if the 86 axle fits into your 450 swinger/bearing carrier.