What the hell is up with my motor?

[Honda 250r 001]

Alright went to the dunes this weekend and it kept running hot. Looked down at the gauge multiple times and it was pegged at 250 degrees. So i started running the choke all the time thinking it was lean, and it worked but it still ran like 225. It was blowing blue smoke when it was wide open. What gives here? I have ALWAYS had trouble with my motors cooling. The water pump is good and no corrosion, the radiator is mint. 190 compression on pump fuel with octane booster.

Is she detonating? Should i start by dropping the comp 10 psi and do a leak down check, or maybe a esr trx 5 centermount?

Thanks

ct 310
rad valve
dyno port exhaust
39 pwk, 175 main needle on the middle and a 50 pilot
190 comp

[headache]

it may be your compression. I'd try some higher octane fuel and see what happens. What was the temp outside? whats your elevation that your riding at?

[86 Quad R]

the very first thing i would do is a leakdown test. if that passes then i'd plug chop it in all ranges. if that passes then i'd either drop the compression or raise the fuels octane and give it a whirl.

a side note................. make sure your silencer isnt clogged or similar. :cool:

[Honda 250r 001]

Originally posted by headache
it may be your compression. I'd try some higher octane fuel and see what happens. What was the temp outside? whats your elevation that your riding at?

elevation is 1400, it was 65 degrees out..

[Honda 250r 001]

Originally posted by 86 Quad R
the very first thing i would do is a leakdown test. if that passes then i'd plug chop it in all ranges. if that passes then i'd either drop the compression or raise the fuels octane and give it a whirl.

a side note................. make sure your silencer isnt clogged or similar. :cool:

i just got the exhaust not long ago, maybe i will have to see if its clogged.

[1promodfan]

Let me tell ya a secret on the octane booster....DON'T RUN IT!! My cousin ran some in his quad, and had to rebuild his top-end.

Also, check for any leaks (leak down test). Mine was running hot like yours is, and it was my intake boot leaking. Fixed it and haven't ran over 200* since.;)

[headache]

I'm with 86 quad r on this one.. Get a gallon of 110 and mix it half and half with some 93 and try it..

[Honda 250r 001]

Originally posted by headache
I'm with 86 quad r on this one.. Get a gallon of 110 and mix it half and half with some 93 and try it..

i will get a gallon and try it, but i cant afford to run race fuel. i burnt prolly 25 gallons of gas on out dune trip and thats wayyyy to much to pay for race fuel.

the only reason i was running octane booster to help it from detonating which i know im pushing it.

[86 Quad R]

Originally posted by Honda 250r 001
i will get a gallon and try it, but i cant afford to run race fuel. i burnt prolly 25 gallons of gas on out dune trip and thats wayyyy to much to pay for race fuel.

the only reason i was running octane booster to help it from detonating which i know im pushing it.

sakes alive son!!! how you manage to consume 'at much fuel? you dang near have to be leaving a solid trail from a leak for me to burn 'at amount. :eek2:

[Honda 250r 001]

Originally posted by 86 Quad R
sakes alive son!!! how you manage to consume 'at much fuel? you dang near have to be leaving a solid trail from a leak for me to burn 'at amount. :eek2:

i went through a tank every 3 hours... i was running with the choke on trying to keep it from blowing up, but still it was very depressing. the ol pwk 39 is thirsty lol.

maybe it was more like 15 gallons, but my friends with their 450rs only had to fuel twice during the whole trip, me like 50 times haha

[1promodfan]

Originally posted by Honda 250r 001
i will get a gallon and try it, but i cant afford to run race fuel. i burnt prolly 25 gallons of gas on out dune trip and thats wayyyy to much to pay for race fuel.

the only reason i was running octane booster to help it from detonating which i know im pushing it.

I gotta agree with 86 Quad R on that one. Thats a lot of fuel to burn. I went out on a two day trip the other day and I might have burn 9 gallons.......and I did a lot of riding, and a LOT of drag racing.

You keep burning that octane booster and running it with the choke on, your gonna be buying a new piston soon:rolleyes:

Man told me once, you wanna play, you gotta pay. Either you need to at least burn 50/50 mix on your fuel or change to a pump gas dome.

[Honda 250r 001]

Originally posted by 1promodfan
I gotta agree with 86 Quad R on that one. Thats a lot of fuel to burn. I went out on a two day trip the other day and I might have burn 9 gallons.......and I did a lot of riding, and a LOT of drag racing.

You keep burning that octane booster and running it with the choke on, your gonna be buying a new piston soon:rolleyes:

Man told me once, you wanna play, you gotta pay. Either you need to at least burn 50/50 mix on your fuel or change to a pump gas dome.

im running a pump gas dome and a stock thickness base gasket. Im wanting to drop the comp back down, but i dont know how? im running a esr pump gas done.

[1promodfan]

You sure its a pump gas dome?

[Honda 250r 001]

Originally posted by 1promodfan
You sure its a pump gas dome?

pretty sure, the guy that sold it to me said it was. Dont you have one for sale? What are the numbers on the top of it i will see if they match mine.

[1promodfan]

Originally posted by Honda 250r 001
pretty sure, the guy that sold it to me said it was. Dont you have one for sale? What are the numbers on the top of it i will see if they match mine.

Mine just says ESR 310 pump on it.

[Honda 250r 001]

Originally posted by 1promodfan
Mine just says ESR 310 pump on it.

how much do you want for your dome?

[machwon]

Originally posted by Honda 250r 001
im running a pump gas dome and a stock thickness base gasket. Im wanting to drop the comp back down, but i dont know how? im running a esr pump gas done.

run an extra base gasket, that should help out on the compression.

Need a leak down tester? If so I make them for $48 shipped.

Otherwise, did it have any other symptoms of overheating? You may want to grab something to verify the accuracy of your temp gauge.

[1promodfan]

Originally posted by Honda 250r 001
how much do you want for your dome?

PM sent.......

[C-LEIGH RACING]

At 65* you shouldnt be having heating problems, but that is a dry heat out west.
Your either sucking air from somewhere causing a lean engine or that water pumps not flowing coolant fast enough. Could be the pump impellars worn on the end & not pumping like its suppose to.
Also if that is an old pipe, check the core on the silencer make sure its in place. Not umcommon for the core to break loose & block the exhaust & bottle up the heat backinto the engine.

:p :p :eek: When you put that engine together & while you were putting the head on, you did put the head gasket on with the little holes to the front over the exhaust, :D right.
Neil

[Honda 250r 001]

Originally posted by C-LEIGH RACING
At 65* you shouldnt be having heating problems, but that is a dry heat out west.
Your either sucking air from somewhere causing a lean engine or that water pumps not flowing coolant fast enough. Could be the pump impellars worn on the end & not pumping like its suppose to.
Also if that is an old pipe, check the core on the silencer make sure its in place. Not umcommon for the core to break loose & block the exhaust & bottle up the heat backinto the engine.

:p :p :eek: When you put that engine together & while you were putting the head on, you did put the head gasket on with the little holes to the front over the exhaust, :D right.
Neil

actually im running a 310, so i use o rings. Maybe i will get a brand new impellar and try that? I will try a leak down test and see how bad it really is. The silencer looks good but not sure how plugged the expansion chamber may be. Last time i was pegged a 250 degreees was when i blew a base gasket. So im thinking leak down test first.

Machwon. I might just have to pick up a tester from you. Ive been wanting one for a while.

Thanks guys.

[C-LEIGH RACING]

:D :D :p Yeah,, I was jus picking at you on the head gasket.

Sometimes over the years, the impellars will get damaged on these old engines & not pump like they are suppose to.
Normaly it is from the balancer bearing being ran to long in a worn out state & then transmitting the flop into the water pump shaft & bearing wearing it out causing the end of the impellar to drag aginst the defuser tin wearing it.
The impellar need to have a good tight clearance between the defuser tin & the tip of the impellar so it can force the coolant out & up to the inlet on the cylinder. If the impellars worn on the end, just that little gap at the end of the fins can disrupt the flow.

Lot of people never think of it, but the end of the impellar & the pump cover defuser tin would be an item one would need to clay & check clearance on to be sure it was good & tight between each other. Just something to think about.
Neil

[Honda 250r 001]

Originally posted by C-LEIGH RACING
:D :D :p Yeah,, I was jus picking at you on the head gasket.

Sometimes over the years, the impellars will get damaged on these old engines & not pump like they are suppose to.
Normaly it is from the balancer bearing being ran to long in a worn out state & then transmitting the flop into the water pump shaft & bearing wearing it out causing the end of the impellar to drag aginst the defuser tin wearing it.
The impellar need to have a good tight clearance between the defuser tin & the tip of the impellar so it can force the coolant out & up to the inlet on the cylinder. If the impellars worn on the end, just that little gap at the end of the fins can disrupt the flow.

Lot of people never think of it, but the end of the impellar & the pump cover defuser tin would be an item one would need to clay & check clearance on to be sure it was good & tight between each other. Just something to think about.
Neil

**** im not even sure mine has a tin in it. Im gonna pull the cover off tonight and see what it looks like in there and i might have to order me a new impellar.

[BA400R]

YOU CAN BUY MY 440 POLONDA MOTOR AND GET RID OF YOUR OVERHEATING PROBLEM.LOL:confused:

[C-LEIGH RACING]

Originally posted by Honda 250r 001
**** im not even sure mine has a tin in it. Im gonna pull the cover off tonight and see what it looks like in there and i might have to order me a new impellar.


Look at the pump cover real close, should be the cover, a gasket, the defuser tin & then another gasket on the clutch cover.

If that defusers not in there, its a wonder its not running hotter than it is, because flow would be disrupted like crazy.
Neil

[C-LEIGH RACING]

Originally posted by BA400R
YOU CAN BUY MY 440 POLONDA MOTOR AND GET RID OF YOUR OVERHEATING PROBLEM.LOL:confused:

What you looking to get for that polo, where all you listed it so far.
Neil

[All250R]

Neil obviously knows better, so i think he misspoke. The large hole goes over the exhaust side, not the small hole.

Something to consider: if you have a high temp in the coolant, that most directly means the cooling system is extracting heat from the engine. If the coolant were very stagnant, the temp would drop in the line and the cylinder temp would rise. Coolant temperatures are more accurately a measure of how well the water is pulling heat energy from the engine, and secondarily how much heat was in the cylinder. if you want to know how hot the cylinder is, the most accurate way is to put a CHT gauge on the head. Just something to think about. If the impeller is intact though, the tin is only 8 dollars or so. I never reuse them.

My thinking would be to start asking why the system is pulling so much heat from the cylinder. ANYone who does work enough to replace a reed cage needs a leak down tester. Work with jetting next. Check the spark plug for bits of aluminum. If none, peer down the hole and see if you can find pitting on the piston top. If none, back the jetting off a few notches across the board and see if it blubbers or if it still runs well. Check temps running it like that. Check the advance on your ignition too... there are several variables... Your first concern is ensuring there are no leaks in your engine. I'd bet lunch money your problem is there maybe around the reed cage area.

[Honda 250r 001]

Originally posted by All250R
Neil obviously knows better, so i think he misspoke. The large hole goes over the exhaust side, not the small hole.

Something to consider: if you have a high temp in the coolant, that most directly means the cooling system is extracting heat from the engine. If the coolant were very stagnant, the temp would drop in the line and the cylinder temp would rise. Coolant temperatures are more accurately a measure of how well the water is pulling heat energy from the engine, and secondarily how much heat was in the cylinder. if you want to know how hot the cylinder is, the most accurate way is to put a CHT gauge on the head. Just something to think about. If the impeller is intact though, the tin is only 8 dollars or so. I never reuse them.

My thinking would be to start asking why the system is pulling so much heat from the cylinder. ANYone who does work enough to replace a reed cage needs a leak down tester. Work with jetting next. Check the spark plug for bits of aluminum. If none, peer down the hole and see if you can find pitting on the piston top. If none, back the jetting off a few notches across the board and see if it blubbers or if it still runs well. Check temps running it like that. Check the advance on your ignition too... there are several variables... Your first concern is ensuring there are no leaks in your engine. I'd bet lunch money your problem is there maybe around the reed cage area.

My plan right now is to check the intake. im running a rad valve, so im going to replace the rubber connector piece, i know the gasket is good on the cage. Then im going to jet up about 5 jets and try a leak down test. We will see how it comes out. I pulled my radiator line off and reved it up and it flowed good. Im running my inline temp gauge in the top line, so it would be measureing degrees from right out of the cylinder.

[All250R]

Do one thing at a time is my advice. Do the leak down test first. Fix that obviously if there is one and then do the jetting change only if the temps don't come down to normal after the leak fix. You're not running 250* of coolant temp because its normal. You have an issue that ideally you isolate a cause for because you don't want to mask the issue with some other change and think you solved the problem. The best way to do that is to be systematic. It takes longer, but you're smarter for it when you discover the problem.

Your temp gauge is in the right place to give the best indication how much heat the cylinder is shedding into the coolant.

[1promodfan]

Originally posted by All250R
Your first concern is ensuring there are no leaks in your engine. I'd bet lunch money your problem is there maybe around the reed cage area.

Thats what I was thinking. When mine was overheating, that was the source.

[QUOTE]Originally posted by Honda 250r 001
My plan right now is to check the intake. im running a rad valve, so im going to replace the rubber connector piece [QUOTE]

That was the problem on mine. That rubber boot was cut at the wrong angle (I cut it) so the carb. was not getting a good seal.

[jhtrx250r]

Look, I have seen good info on this forum and I have sen bad,
So I will just get to the point STOP!!! running octane booster in your 2 stroke !!!!!!!!!, I think I saw you had 190comp in the post some where thats fine for super, better if you run AV gas but you dont seem to want to spend the money on the correct fuel.
What ever you try STOP with the octane boost it is mostly ethonal/methonal or laqure none of those will cool your engine they only make it run hoter! adding octane boost to your fuel will rase you internal combustion temp 30+ degrees, I have seen way to many dumb ***** riders try this to save money, the first step is over heating, the second is a hole right in the top of your piston.
Either buy the good 100+ octane fuel (that will make your motor run much cooler) or lower your comp to 175 that seems to be the safest for riders who dont work on their quads

[BA400R]

Re: .

quote:
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Originally posted by BA400R
YOU CAN BUY MY 440 POLONDA MOTOR AND GET RID OF YOUR OVERHEATING PROBLEM.LOL
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What you looking to get for that polo, where all you listed it so far.
Neil


$2000 for complete motor.it has all new seals, bearings,crank,piston and rings