My New Honda 87 250es Big Red

[AussieATC]

Hi guys,

My 250es Big Red that I just bought got delivered today and I am planning on installing a new timing chain, piston, rings and valves. I am just interested to know if anyone would like me to upload pictures or videos on any of the processes?

-Alex

[tri again]

Hey there.

IF you can, it's always appreciated.
There might be some stuff posted but more is better.

Why do you want to do all that work?
Does it need it?
Low compression?
Timing chain noise?
Is it new to you?
Does it run now?

and as always, make sure the gear oil in the rear axle is nice and clean.

service manual

should get you some good info too.
And whatever you do do NOT loosen the allen bolts that hold the right angle output for the driveshaft.
There's a deeply buried internal spacer that drops down inside and requires way more disassembly that should ever be necessary.

I happen to have an 'extra' 250es engine but it's an 85 that was submerged.
Might be a good candidate to rebuild in the unlikely event I need a quick engine swap.

Pretty sure they made less than 5,000 of the 87 models.
(I'm one of the lucky few too)
I know the chain tensioners are different so you may want to source ALL your parts before you get started.

In any event, please keep us posted, good luck and have a good time.

[AussieATC]

To answer your questions,
The timing chain was warn and jumped a tooth and the valve to hit piston which broke the valve. So I figured while I have most of it apart I will put a new piston and rings in aswell.

-Alex

[tri again]

To answer your questions,
The timing chain was warn and jumped a tooth and the valve to hit piston which broke the valve. So I figured while I have most of it apart I will put a new piston and rings in aswell.

-Alex

oooh, ouch.
so sorry.

yeah, timing chain tensioner and maybe even the guide rails for the chain.
Check the search key for more info.
There may be something else to check for, like bent cam chain wheel but surely someone has been through this before and will chime in soon.

They really should run forever so maybe measure the cylinder bore somehow in case you need to go up a piston size.

Maybe an extra 100 bucks if it's needed but it will run another 25 years.

I think you got me thinking about rebuilding an 'extra' engine.

and as always, we like pictures.
It helps to take the sting out of the pain when you pass them around.

[AussieATC]

Glad to hear it hahaha and yeh ill post the pictures as soon as I get started.

[dustrunner]

alway like looking at any 87 atc...or 88 also....

[trike savior]

it would be nice to have someone with videos on here to show how its done. ive been thinking about making some myself but just do not have the time. like i said in one of your other posts i have seen that engine failure alot and i hope you have checked your other bikes as well. along with what you are doing already check the chain guides for wear and check that the self-tensioner works properly. do you have the tool to disassemble the valves because it is easily made and i can post some pics of mine if you dont have it yet.

as far as the engine: if the valve seats look clean enough (no damage) new valves should work without cutting seats. lapping compound is a plus but i have had them seal just fine. i always check though by pouring gas in combustion chamber and making sure it holds the fuel for a few minutes.

and the new piston might not be necessary unless you find it cracked from hitting valves like the one i talked aboout. i do not know if you have measuring tools but most of the engines i have run across with same problem still have piston to cylinder clearence well within spec. in most situations the rings are just what need replaced.

good luck and keep us posted

[AussieATC]

Yeh could you post some pictures of that tool?

Thanks

[trike savior]

sorry it took me so long I had a hard time finding the little bugger. this is actually the first one I made and quit using cause I made a longer one with bigger windows. so make it as long as you can for the size c-clamp you have. and larger tube is better too. I had no choice with this cause I was using it on my 110/125's but it still worked on 250s just not as much room to get keepers out. use solid base of c-clamp against valve and this between screw side and retainer. compress the valve spring and use a magnetized screwdriver or pick to get keepers our good luck

[trike savior]

the newer one I made only had about 1/4" of metal at bottom and between windows which made it a lot easier to get at keepers. and this only needs to be made from 1/8 wall tubing but thicker wall plumbing pipe will work fine too. I used a dremel with cutoff wheel to cut windows cause it is easier to control than large angle grinder

[AussieATC]

Ok will do

Thanks