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1999 fourtrax 300 running rugh

3047 Views 20 Replies 4 Participants Last post by  shadetree
hello I recently perches'ed a 1999 honda fourtrax 300 4X4 and it was burning oil so I got a gasket kit and took the engine apart removed the old gaskets and seals and installed the new ones then put it back together and adjusted the timing then I went to start it and I had to give it a bit of throttle for it to start and the it would run really rough. Why? It allways ran vary well and smooth.
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most old Honda's are 0.006.
Well I was right the timing was off so I got it right and it still ran a little rough so I cleaned the carb and now it runs great. Compression cold is 180 psi and hot is 170 psi thanks for your help
Good work Tractorboy, compression is steering towards the low side but if your not a hard rider it should see you another season before you want a top end build.

Since you've had it apart doing gaskets etc now would probably be a good time to do an oil and filter change too, maybe throw a new spark plug in at the same time ;-)
180 psi is low ?....ummmm..maybe I missed the short little yellow bus again ?, but I know for a fact !!, the trx300's ( most ), have a min of 100 psi to just run, and your saying 180 psi is low ?
good deal OP !!.
170 is his warm reading, 180 cold so Yeah.. it's on the lower side of the FSM spec. 176 to 201 i think it is.. it may run at 100 but it's not right, there underpowered as it is, I dread to imagine what 100psi compression is like!
trx300's will crank and run at 100 psi, anything lower than this ?, they just won't act right. 170-180 will run a long time before it needs a top end job, take my word on this !
I agree, it will run, but it's not right, hence Honda specifying 178 to 206. I advised the OP as per the FSM specs ;-)
and your right, Honda specs WANT you to replace his psi is fine for a long time, not arguing your point, your point is valid, my point is, he can run that trx300 for a few more years before he needs to do a top end job :).
Here here.. We'll agree to disagree then lol :)
agreed !..lmao.
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