Honda HRC 450RR

[factoryX]

i want to see a raptor 700 in one....

[250rfan]

Well, a raptor engine?, i dont know, possibly someone else may want to tackle that one,,,,,

Jason - all of your questions will be answered as this project progress's, i guess you'll just have to keep on viewing this thread.


Okay, now the engine is in, i need to sort out a few issues, as you can see from the first pic the water spiggots from the engine and the radiator are quite close, but the radiators are still in the HRC position, so once i move them back to there original position the hoses will fit no problem.

The second pic shows the bottom of the engine and how close it sits to the frame, to address this i will bend the 2 lower frame tubes to a more straight/horizontal angle, this will let the engine sit level with the ground and will allow me to re mount the OEM lower engine mountings which i cut of earlier. i will also cut the forward facing frame tubes and lower them, so they join the lower frame tubes.

The other pics show the engine from the right hand side.

[jeffatc250r]

Awesome! Cant wait to see it done, i think it will be the perfect combination.

[250rfan]

Okay, the engines been taken out, and the original lower engine mounts re fitted, i have also straightened the lower frame tubes to a more horizontal angle, allowing the engine to sit horizontal with the ground and to give clear access for installing and removing the OEM lower engine mounting bolt + nut.


Right, next issue is the carb!,,,,

[Nightbiker07]

i want to see a raptor 700 in one....

why? the 450's are a stronger motor tan the Craptor motor, and all that EFI garbage is EXPENSIVE when it takes a crap in 7 years or so.........you wont see no 07 craptors in 2030, guranteed.............but ill bet youll still see old 84 trikes!

[Derrick Adams]

I'm curious what your going to do to get around the chain clearance issue. Seems as if tilting the motor that far up will cause the chain to run right into the swingarm along the bottom.

[250rfan]

I'm curious what your going to do to get around the chain clearance issue. Seems as if tilting the motor that far up will cause the chain to run right into the swingarm along the bottom.

.



Derrick am not sure exactly what you mean when you say tilting the motor that far up, the engine is level to the ground as is the case in any atc / atv / m'c.

The swingarm is alined perfectly with the engine, because the swingarm pivot bolt aligns everything, sprockets, height in relation to the front sprocket and frame ect.


I have attached a picture which might answer your question better than i can explain - as you can see there are no issues with the chain and swinger.

Also for the record, i have and will take pictures all through this build and i'm amazed that after 22 years the geometry of the honda has'nt really changed that much, as this project advances you will see the the engine, swinger, suspension, brakes, exhaust, radiators, airbox ect all fit onto the 1985 250r frame with very little modification, basically showing that Honda had it right more than 20 years ago- or there now very lazy!!!!!,,,,,, i like to think they had it right 23 years ago!.

Allready you can see that the rear swingarm fits into the frame with no modification needed, you dont have to widen the frame or open or narrow the swingarm bolt holes
at all, it simply fits straight into the frame, using the OEM TRX 450 swingarm bolt. Also if am correct the OEM TRX 450R swingarm length is the same as the 85/86 250R


Thanks for yourself and Jasons questions, these are the questions which have been running around my head well before i started this build, i think i have overcome everything, as the build continues you will see all Major issues will have been overcome.

[Derrick Adams]

In the last picture it looked as if there was going to be an issue with it.

See how it appears as if the bottom of the sprocket is going to run the chain right against the bottom of the swinger? Just a camera trick I guess.

[Derrick Adams]

Here's another suggestion for you. If you wanted to try to keep the frame looking close to stock in the front you could possibly lay back your cradle tubes.

The front motor mount would have to be reconstructed using possibly a thru bolt design (thru the frame). Or a flush bolt design at the engine and then bolted conventionally to the frame.

Your making some huge headway on this project. Can't wait to see it finished and hear how it runs.

P.S. seems like I remember the 450R swinger being shorter than the 250R one, so you should have a wheelie machine on your hands!

[sandpuppi101]

Your build look's like it's coming along very nice,and it'll be nice too see it when it's done.I have a few question's on the suspension,I can see that the machine is laying Flat I guess you could say ,with the motor in,and you say you gave up ground clerance on dropping the cradle.Now Derrick bring's up a good point,if you are gonna run the stock 450 swinger ,your gonna have a wheelie machine on your hand's..Do you plan on stretching the swinger any?? If so your stock shock is gonna become mush,don't ya think.Food for thought is that you drop your top rear shock mount from the backbone and weld a gusseted crossmember about 2 inche's lower than the existing mount ,on the subframe ,and you will not only give yourself clerance for the carb /airbox tube's but you will also be changing the angle of the shock and gaining the clerance that you'd like to have on the lower cradle.I could see the headpipe as being an issue going that way,but I can't see a good angle of the right side upper cradle.I had to do someting quite similar to the 600 build..

[Jason Hall]

The 06 & up 450r swingarm Is the same length as a stock 85-86 250r swingarm. The 04-05 450 swinger Is 1" shorter than a stock 85-86 R. The 04-05 swinger Is the same length as a 88-89 TRX250r & the same as a 400EX.

I know from experiance you will have a blast tucking that big huge TRX wire harness under the tank on the R. That was one of the things I remember most about the 05 TRX engine I origionally put In my bike. I stuffed alot of the wires up In the main tube under the gas tank.

Looks great so far. It also looks like you might be able to use a stock 250r air box & carb boot. Clearance Is close, but looks like It will work.

[250rfan]

Here's another suggestion for you. If you wanted to try to keep the frame looking close to stock in the front you could possibly lay back your cradle tubes.
The front motor mount would have to be reconstructed using possibly a thru bolt design (thru the frame). Or a flush bolt design at the engine and then bolted conventionally to the frame.

Good point Derrick, but am trying to keep this build as simple a possible, am using as much of the OEM frame as possible (am also using a donor 85 frame), i could have made special tubes to cut the frame in closer to the engine but the way i have done it is the easiest, also - remember you need space around the engine for installing & removing the engine.

Thanks again for your suggestion.

Sandpuppi101:- Good points on the rear swinger and shock issues -

YES - I will be be using an extended swinger.
YES - The stock shock would possibly be mush, but stock OEM is very firm.
YES - I will not be using stock OEM shock.
YES - I will be replacing the upper shock mount ( will be shown latter in thread)
There will be no issues with the carb, airbox, induction tube, headerpipe, will be shown latter in thread.

Jason - Yes i will be using the stock 85 airbox, induction tube.

[Jason Hall]

Derrick & I know exactly how stiff the 450r rear shock's are when on a 3 wheeler, they are stupid stiff. The valving Is stiffer & so Is the spring by FAR. I think the reason Is the sub frame Is longer on the TRX frame. That gives you more leverage to push the suspension down. I bet you could put a +6 on there & It would still not be as soft as a stock R rear shock.

[250rfan]

Derrick & I know exactly how stiff the 450r rear shock's are when on a 3 wheeler, they are stupid stiff. The valving Is stiffer & so Is the spring by FAR. I think the reason Is the sub frame Is longer on the TRX frame. That gives you more leverage to push the suspension down. I bet you could put a +6 on there & It would still not be as soft as a stock R rear shock.

Ye Jason, your right, the OEM rear shock is very very stiff.


Okay guys, back to the build, next issue is the carb -

Pic #1 shows the carb just placed against the engine the upper frame tube is stopping it from fitting correctly.

Pic #3 shows the carb at a different angle, you can see the piggy back remote for the shock aslo in the pic, this is one of the reasons am not using th OEM rear shock, i need a remote reservoir, to leave space for the air box induction tube.

Pic #1 shows the carb from the right hand side, you can see where the top of the carb is hitting the frame, i have 2 options at this point :-
option 1 = cut a notch out of the frame, box it in latter.
option 2 = find a shorter carb.
* I'm going for option 1 cut a piece out of the frame, plate it in to re-establish strength*.

Pic #4&5 = shows the carb in place.

[Mosh]

Ye Jason, your right, the OEM rear shock is very very stiff.


Okay guys, back to the build, next issue is the carb -

Pic #2 shows the carb just placed against the engine the upper frame tube is stopping it from fitting correctly.

Pic #3 shows the carb at a different angle, you can see the piggy back remote for the shock aslo in the pic, this is one of the reasons am not using th OEM rear shock, i need a remote reservoir, to leave space for the air bix induction tube.

Pic #1 shows the carb from the right hand side, you can see where the top of the carb is hitting the frame, i have 2 options at this point :-
option 1 = cut a notch out of the frame, box it in latter.
option 2 = find a shorter carb.
* I'm going for option 1 cut a piece out of the frame, plate it in to re-establish strength*.

Pic #4&5 = shows the carb in place.

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