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Trx 350 won't start
Hey I'm new to this forum ...I just bought a 1991 honda fourtrax trx 350 4x4 ...Canadian model anyways it had busted intake valves when I got it and the kick start was seized I just replaced the valves times it replaced the spark plug drained the old dirty fuel and cleaned the carb the electric start has no gears in it BTW. I got the kick start to move nicely now but there's nothing the only thing it does is give a pop from the tail pipe the lift pump is pimping fuel to the carb spark plug has a nice blue spark and it has a new battery
 

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Did you rebuild the carb IAW the manual, esp the idle screw--common mistake is to run it all the way in. My experience with these carbs it that they have to be very clean, the choke plunger has to have a good seal and vacuum lines all seated.

Could be a bad CDI there's an ignition system troubleshooting guide in the manual. Will help you ohm out the CDI and fuel relay

Will it fire and try to start with a lil shot of starter spray (careful if it backfires there's lotta plastic to burn).
 

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I don't have a manual for it I haven't tried to start it with starter spray I may try that and see what happens. Is the compression supposed to blow my thumb off when I place it over the spark plug hole.....
 

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I don't have a manual for it I haven't tried to start it with starter spray I may try that and see what happens. Is the compression supposed to blow my thumb off when I place it over the spark plug hole.....
compression is suppose to be really high on these models, in order for them to run.
 

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if and when you go to locate parts ?, you have a 1989 trx350. Honda does not recognize any year of that model after 1989, yessssssss..I know they sold them up there after 1989 ?, but that does not mean it's a 1991 !.
 

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Ok so would that be bad timing.....I have 4 timing marks one with an f one with a t and 2 plain marks. The head got a bit beat up the spark plug got punctured and the intake valves broke
 

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I don't know what your timing comment was about--you seem to be getting good compression and spark, so unless the timing chain teeth are misaligned I don't think you can adjust

Ok I learnt this starting rules from Shadetree; since you're kicking it this might wear you out a bit:
1) Fuel has to be near or in the carb, so ignition and neutral light on
2) fully choke carb with button to left
3) fully depress throttle and roll back to a third open
4) kick over engine a few times
5) if no start open the air box take off filter
Start over only spray very little fluid in there you want it in cloud form not stream
Does it run maybe for 2-3 seconds?
 

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With the timing the "flywheel" has 4 marks I'm not sure which mark I should time it to so I timed it to the "t" mark. I'll get some starting fluid and try it
 

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Ok just be careful have a heavy cloth and fire stinguisher on hand if it backfires thru the carb you might get a leetle far goin
 

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T mark on the COMPRESSON STROKE !, to set valves and check timing.
 
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Roger that les git er cranked over now! If it putters but won't run then you need to follow troubleshooting for the ignition/CDI
Oh smiley face btw
 

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Discussion Starter #14
Got my brother to look at it today ....he is way smarter than me....the exhaust valves seats are Cracked so I'll bring it into a shop this week to get it fixed
 

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Got my brother to look at it today ....he is way smarter than me....the exhaust valves seats are Cracked so I'll bring it into a shop this week to get it fixed
I have never heard of anyone fixing a cracked valve seat ?, I don't think they can be fixed ?, and I know they can't be replaced !, as they are pressed into the head from the factory. keep us posted please, i'd love to know the out come on this !.
 

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Got my brother to look at it today ....he is way smarter than me....the exhaust valves seats are Cracked so I'll bring it into a shop this week to get it fixed
I have never heard of anyone fixing a cracked valve seat ?, I don't think they can be fixed ?, and I know they can't be replaced !, as they are pressed into the head from the factory. keep us posted please, i'd love to know the out come on this !.
Appears you are going to need a replacement head. I've re-installedvalve seats on small engines that popped out, but 99.99999% of the time if the valves or head was distorted and valve seat or guides involved the head is trash. If a seat is cracked the head took quite a beating. You need to look very close at the top of the cleaned piston for damage like small hole or crack. (Just saying from small engine experience)

When valves sealing (seating) is suspected I can usually lock the engine at TDC on comp stroke and nozzle inject about 20 psi (use a regulator so as to vary the pressure) into the spark plug hole and listen for air leaking at exhaust or carb by ear and get a hint as to which valve or vlaves is not sealing good before pulling the head.
Using low pressure air you can just use a rubber tipped injector and not have to hard plumb the air to the spark plug hole.:wink:

Keep us posted on this one?
 

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Got my brother to look at it today ....he is way smarter than me....the exhaust valves seats are Cracked so I'll bring it into a shop this week to get it fixed
I have never heard of anyone fixing a cracked valve seat ?, I don't think they can be fixed ?, and I know they can't be replaced !, as they are pressed into the head from the factory. keep us posted please, i'd love to know the out come on this !.
Appears you are going to need a replacement head. I've re-installedvalve seats on small engines that popped out, but 99.99999% of the time if the valves or head was distorted and valve seat or guides involved the head is trash. If a seat is cracked the head took quite a beating. You need to look very close at the top of the cleaned piston for damage like small hole or crack. (Just saying from small engine experience)

When valves sealing (seating) is suspected I can usually lock the engine at TDC on comp stroke and nozzle inject about 20 psi (use a regulator so as to vary the pressure) into the spark plug hole and listen for air leaking at exhaust or carb by ear and get a hint as to which valve or vlaves is not sealing good before pulling the head.
Using low pressure air you can just use a rubber tipped injector and not have to hard plumb the air to the spark plug hole.:wink:

Keep us posted on this one?
yep, from what I know of ?, once the valve seat is damaged ?, it calls for a new head, no way around this, not that I know of any way ??.
 
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