Author Topic: 1982 YZ 490 cylinder / IT 490 head  (Read 178 times)

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Offline storie585

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1982 YZ 490 cylinder / IT 490 head
« on: July 11, 2019, 11:22:41 AM »
Anyone here ever run the combination of a 1982 YZ 490 cylinder and an IT 490 head? Thinking of that combination in a 83 IT 490 frame. Any issues? Compression?
Dave

Offline 4V5

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Re: 1982 YZ 490 cylinder / IT 490 head
« Reply #1 on: July 11, 2019, 05:50:39 PM »
downtube clearance will be an issue.
IT465x4 IT400C IT175F YZ465G YZ250C YZ250WR XJ650G RD350LC RD250LCx5 DT175Nx3 TW200x2 DT200L DT200R RT3 RX100G GT80F YZ80L PW50J KH250B1 KZ250D1 PE175C TS250ER TS185ER AG175B AG100

Offline storie585

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Re: 1982 YZ 490 cylinder / IT 490 head
« Reply #2 on: July 12, 2019, 05:40:37 AM »
Sounds easily fixable
Dave

Offline Kickaha

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Re: 1982 YZ 490 cylinder / IT 490 head
« Reply #3 on: July 12, 2019, 04:50:51 PM »
Anyone here ever run the combination of a 1982 YZ 490 cylinder and an IT 490 head? Thinking of that combination in a 83 IT 490 frame. Any issues? Compression?

What are you trying to achieve with this combo compared to the IT490 cylinder?
Eat right
Stay fit
Die anyway

Offline storie585

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Re: 1982 YZ 490 cylinder / IT 490 head
« Reply #4 on: July 14, 2019, 11:37:50 AM »
Spare cylinder mostly, but I had success mounting a 1983 YZ top end on an IT bottom end.. better gearing and more low end... not sure I will reproduce that with the 82 YZ cylinder.. I built another similar motor using 1981 YZ 465 gearbox , IT 490 crankshaft / clutch and a YZ 465 top end that was ported.. I had good results with that engine but I was using a modified cr 250 pipe... great low end but it peedered out mid to top.. the bike is at dynoport in union springs in New York getting a custom pipe built... my 2001 wr250 frame / 465 motor project.. I?m basically addicted to making old junk run awesome...
Dave