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1996 honda xr400r not starting?

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Ok bought this bike from a kid who said the timing chain broke. So i tore the head off and the chain was still good but had some slack so i replaced it with a wiseco one .set the timing mark (T) on crank and cam sprocket Left, up, and right then adjusted the tensioner. still didnt have any compression so i took it back apart and found all four valves bent and stuck open. So i replace them with some wiseco ones and reset the timing again. Then cleaned the carb and replaced the spark plug NGK. tried starting it and got a fire for a second then nothing but turning over. replaced the plugs again and has fresh gas. Im out of ideas can anyone help me out please? It has spark and gas wont even hit off starting fluid.

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it seems to have descent compression also i've checked the timing several times its dead on with the (T) on flywheel and the marks on the cam sprocket and lobes down. I keep reading about the decompression lever but this bike doesnt have the lever or cable on it but the spring and clip is still on the engine?

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When you had the Tappet cover off did you notice whether it still

had all the stuff on the Cam that works the automatic decompression system

from the Cam. If it hasn't got any of that gear on the Cam it may have a Hotcam

of some description in it and the gaps you set for the Tappets for one of

them are different than for the standard Cam. Having the lever still on the side

of the head doesn't mean a lot. You need to id what Cams in it if 400s run the

auto mechanism like later model 600s and set the appropriate gaps for it..

Edited by Horri

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ok im still learning on these bikes so when you say tappets do you mean rockers? the decompressor is not connected so i assume it has a upgraded cam but does anyone know how to tell if its stock or aftermarket to be sure?

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<p><p>Yep..Tappet gaps rocker gaps are the same thing. I don't know how to tell

whether it's a Hotcam or not. If the stuff that controls the auto decompression

mechanism off the Cam is missing it doesn't necessarily mean it's a hotcam.

Some people remove that stuff from the stock cam as it's not needed for them

to have it on the bike. As I said the lever can still be there attached to

its arm in the cover that enables you to use the manual decompressor arm

which is normally on the handlebars. Thing is I don't know enough about modern

400s to know whether it's electric start or what. The electric start models

at least in the 650L version don't have any hand operated decomp on them..

All handled by the mechanism on the cam.,Guess you'd need to get the rocker/tappet

cover off and take a few pictures of the thing for anyone to know what's in there.,

Either that or see if the kid you got it off knows though I somehow doubt he knows ba.</p>

Interesting stuff this code.

Edited by Horri

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Righto,,Normally there are some little holes left over on the body of the cam from the various

bits removed from the auto mechanism. If they are there it's probably just

a stock cam with the mechanism removed. If it's a Hotcam none of those holes

will be present. If that's the case you may then need to get a few more decent

pictures of the actual cam itself to see if there's any identifiable markings

on it and take things from there.,

Edited by Horri

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Did you ever get a look at the piston itself? Something had to have caused the valves to become bent. Piston/valve contact?

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yes i looked at the piston and there wasnt any damage to it or the rings it had no carbon build up on it at all hardly. Aso another thing i forgot to mention is it backfires out of the exhaust every once and a while when i try starting it. also the kid i bought it from said it had a 440 kit on it but i dont see any number stamped on the piston it has KCY stamped on it but that is stamped on the bottom end as well so i assume it is all factory and he lied.

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Yep,,Well backfiring out the exhaust when you try to start it is generally a sign

of tappet/rocker gaps being wrong, If it has a 440 kit in it it'll almost

for certain have a hotcam in it. People that hot bikes up generally go the whole

hog,,ie High comp piston, hotcam, and maybe super dooper carb and exhaust. Have you

got the tappet/rocker cover off as yet and been able to see any numbers or markings

on the cam??,,Must be something stampted somewhere on the body of the thing.

Edited by Horri

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well i was going to post some pictures but not sure where i put my camera. So i tore it back down to the piston to recheck everything here is my findings. I could not find any number or stamps on the cam.The piston is stock bore 87mm is what i read on my caliper. but it was really clean with no scuffs or scrapes. I checked the rings and there all in good shape not stuck or worn almost look brand new. The cylinder itself was in good shape as well not scuffed either so i put some new gaskets on and put her back together and reset the timing. I'm going to recheck valves in the morning and see if it hits off again. ill let everyone know how it goes thanks for the help though everyone any other ideas i should try while i got it tore apart?

Edited by jeremypatrickreed

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So did the Cam have the automatic decompression mechanism on it or not??.

It's no use putting it back together and trying to start it if you or we

don't know what cams in it so we can check the appropriate sites for the

correct gaps. You need to look at a parts fiche of a standard cam with all

the parts on it to know what or if you have the standard cam in there or

whether you have a hotcam in it,,I will try and post a fiche for you..

http://www.serviceho...=1996&fveh=4288 .

4,3,8,35,34,7 and 27 should be on the cam if it still has the auto mechanism

on it. If they aren't on it and the holes/retainers which hold those bits in place are

still on the cam it's stock,.No holes or retainers left over from the removal of those bit's means

it's a Hotcam and you won't know what to

set the Tappet gaps to.

Edited by Horri

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It sure sounds like you know what your doing, but there is a possibility that even with the T mark in right location it may be 1 turn off where it should be. When at right TDC there should be play in the left exhaust valve. The backfire suggests it's the valves, but as said before w/o knowing what cam then you dont know what the valves should be set at.

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thanks for all the help everyone i had a guy offer me 400 for it so i sold it and got rid of the headache but it did have a stock cam with the mechanism on it but it wasnt working for some reason is what the guy told me. again thanks for all the help.

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